diff options
Diffstat (limited to 'old/66998-0.txt')
| -rw-r--r-- | old/66998-0.txt | 4163 |
1 files changed, 0 insertions, 4163 deletions
diff --git a/old/66998-0.txt b/old/66998-0.txt deleted file mode 100644 index 0fb5cb4..0000000 --- a/old/66998-0.txt +++ /dev/null @@ -1,4163 +0,0 @@ -The Project Gutenberg eBook of Rubber Hand Stamps and the -Manipulation of Rubber, by T. O'Conor Sloane - -This eBook is for the use of anyone anywhere in the United States and -most other parts of the world at no cost and with almost no restrictions -whatsoever. You may copy it, give it away or re-use it under the terms -of the Project Gutenberg License included with this eBook or online at -www.gutenberg.org. If you are not located in the United States, you -will have to check the laws of the country where you are located before -using this eBook. - -Title: Rubber Hand Stamps and the Manipulation of Rubber - -Author: T. O'Conor Sloane - -Release Date: December 22, 2021 [eBook #66998] - -Language: English - -Produced by: deaurider, Charlie Howard, and the Online Distributed - Proofreading Team at https://www.pgdp.net (This file was - produced from images generously made available by The - Internet Archive) - -*** START OF THE PROJECT GUTENBERG EBOOK RUBBER HAND STAMPS AND THE -MANIPULATION OF RUBBER *** - - - - - -Transcriber’s Note - - -Subscripts are represented by bracketed numbers preceded by an -underscore: C_{10}H_{16}. - - - - -BY THE SAME AUTHOR. - - -Arithmetic of Electricity. - -A Complete and Indispensable _vade mecum_ for amateur, student, and -electrical engineer. - - Fully Illustrated. Price, $1.00. - - -Home Experiments in Science. - - 252 Pages. 96 Illustrations. Price, $1.50. - - - - - RUBBER HAND STAMPS - AND THE - Manipulation of Rubber - - A PRACTICAL TREATISE ON THE MANUFACTURE OF INDIA RUBBER HAND - STAMPS, SMALL ARTICLES OF INDIA RUBBER, THE HEKTOGRAPH, - SPECIAL INKS, CEMENTS, AND ALLIED SUBJECTS - - BY - T. O’CONOR SLOANE, A.M., E.M., PH.D. - - Author of - “Home Experiments in Science,” “Arithmetic of Electricity,” etc. - - - FULLY ILLUSTRATED - - - NEW YORK - NORMAN W. HENLEY & CO. - 150 NASSAU STREET - 1891 - - - - - COPYRIGHT, 1890, BY - NORMAN W. HENLEY & CO. - - - - -PREFACE. - - -The present work hardly needs a preface. The object is to present in -the simplest form the subject of the manipulation of india rubber. To -mould and cure the mixed gum but few appliances are needed, and these -can be made at home. The articles produced are of more than ordinary -utility. These two facts give value to the art and furnish a _raison -d’être_ for this book. If its instructions do not prove practical it -will have missed its object. - -For some reason the methods of moulding the material are not generally -known. Experiment has taught many the futility of attempting to -melt and cast it. While thus intractable by the usual methods, it -is the most plastic of materials when properly treated. Its power -of reproducing the finest details of a mould, of entering all the -intricacies and undercuttings of a design, cause one to feel a peculiar -pleasure in working with so responsive a material. It is not saying -too much to affirm that to some readers this book will disclose a long -hidden secret. To make it more generally useful it is written for such -readers, to meet the want of those knowing of the subject. It was felt -that in following this course, and in treating the subject from its -first steps, including the simplest as well as most advanced methods, -the book would appeal to a larger body of readers. - -The allied subjects to which some chapters are devoted will be -acceptable to many readers. The hektograph is given in several -modifications. A substitute for rubber stamps which stands the severe -usage of the Post Office has very distinct merits, and the manufacture -is accordingly described in detail. Cements and inks embody many -special formulæ. In the last chapter interesting and practical notes -will be found. - -For the use of certain cuts we are under obligations to the Buffalo -Dental Manufacturing Co., Messrs. E. & F. N. Spon & Co., and to Mr. L. -Spangenberg. - - - - -CONTENTS. - - - PAGE - CHAPTER I. - - THE SOURCES OF INDIA RUBBER AND ITS HISTORY. - - The Trees--The Sap--Caoutchouc--Early Uses by the - Indians--First knowledge of it in Europe--Goodyear, Day, and - Mackintosh 9 - - - CHAPTER II. - - THE NATURAL HISTORY AND COLLECTION OF INDIA RUBBER. - - African, East Indian, Central and South American - Gums--Different Methods of Collection and Coagulation 15 - - - CHAPTER III. - - PROPERTIES OF UNVULCANIZED AND VULCANIZED INDIA RUBBER. - - Properties of Unvulcanized Rubber; its Cohesion - and importance of this property--Analysis of Sap and - Caoutchouc--Effects of Heat and Cold--Distillation - Products--Vulcanized Rubber, and its Properties 24 - - - CHAPTER IV. - - THE MANUFACTURE OF MASTICATED, MIXED SHEET AND VULCANIZED - INDIA RUBBER. - - Treatment by the Manufacturer--Washing and - Sheeting--Masticating--Making Sheeting and - Threads--Mixing--Curing--Coated Tissues 35 - - - CHAPTER V. - - INDIA RUBBER STAMP MAKING. - - Mixed Sheet--Outlines of Moulding--Home-Made Vulcanizing - Press--Further Simplifications of Same--Securing Accurate - Parallelism of Platen and Bed--Distance Pieces--Wood vs. - Iron as Material for Press--Use of Springs on the Home-Made - Press--Metal Flask Clamps--Large Gas-Heated Vulcanizing - Press--Preparing Type Model--The Matrix--Plaster of Paris and - Dental Plaster as Substances for Matrices--Dextrine and Gum - Arabic Solutions for Mixing Matrix--How Matrix is made--Shellac - Solution for Matrix--Matrix Press and Spring-Chase--How to - retard the Setting of Plaster of Paris--Oxychloride of Zinc - Matrices--Talc Powder--Moulding and Curing the Stamp--Kerosene - Heating Stove--Manipulation of Press--Degree of Heat--Simple - Test of Curing--Time Required--Combined Matrix Making and - Vulcanizing Apparatus--Chamber Vulcanizers--Object of Steam - in Vulcanizers--Temperature Corresponding to Different Steam - Pressures--Jacketed Vulcanizers--Gas Regulator--Flower - Pot Vulcanizer--Fish Kettle Vulcanizer--Making Stamps - without any Apparatus Whatever--Notes on Type, Quadrats and - Spaces--Autograph Stamps 47 - - - CHAPTER VI. - - INDIA RUBBER TYPE MAKING. - - Movable Type Making--Simple Flask and Matrix--Precautions - as to Quantity of Rubber--Moulding--Curing--Cutting Type - Apart--Special Steel Moulds--Wooden Bodied Type 73 - - - CHAPTER VII. - - THE MAKING OF STAMPS AND TYPE FROM VULCANIZED INDIA RUBBER. - - Ready Vulcanized Gum as Material for Stamps--Simplicity - of the Process of Using It--Advantages and - Disadvantages--Availability for Type 77 - - - CHAPTER VIII. - - VARIOUS TYPE MATRICES FOR RUBBER STAMPS AND TYPES. - - Electrotype Matrices--Papier Maché--Flong Paste--Flong - Matrices--Beating into Model--Drying and Baking--Struck-up - Matrices--Chalk Plates 80 - - - CHAPTER IX. - - THE MAKING OF VARIOUS SMALL ARTICLES OF INDIA RUBBER. - - Suction Discs--Pencil Tips--Cane and Chair Leg - Tips--Corks--Mats--Cord and Tubes--Bulbs and Hollow Toys 85 - - - CHAPTER X. - - THE MANIPULATION OF SHEET RUBBER GOODS. - - Sheet Rubber Articles--Toy Balloons--Uses of Sheet Rubber in - the Laboratory 94 - - - CHAPTER XI. - - VARIOUS VULCANIZING AND CURING PROCESSES. - - Liquid Curing Baths--Sulphur Bath--Haloids and Nitric - Acid as Vulcanizers--Alkaline Sulphides--Sulphur Absorption - Process--Parke’s Process 97 - - - CHAPTER XII. - - THE SOLUTION OF INDIA RUBBER. - - Mastication with Solvent--Peculiarities of - the Process--Different Solvents and their - Properties--Paraffin--Vulcanized Rubber Solution--Aqueous - Solution 103 - - - CHAPTER XIII. - - EBONITE, VULCANITE AND GUTTA-PERCHA. - - Ebonite and - Vulcanite--Manufacture--Manipulation--Gutta-Percha and its - Manipulation 108 - - - CHAPTER XIV. - - GLUE OR COMPOSITION STAMPS. - - Substitute for Rubber Stamps--The United States Government - Formula--Models and Moulds--Dating--Handles 113 - - - CHAPTER XV. - - THE HEKTOGRAPH. - - How Made--The French Government Formula--Hektograph Sheets 121 - - - CHAPTER XVI. - - CEMENTS. - - Marine Glue, and other special Cements 125 - - - CHAPTER XVII. - - INKS. - - Hektograph, Stencil and Marking Inks--White and Metallic Inks 129 - - - CHAPTER XVIII. - - MISCELLANEOUS. - - Preservation and Renovation of India Rubber--Burned Rubber - for Artists--India Rubber Substitutes--General Notes of - Interest 134 - - - - -RUBBER HAND STAMP MAKING AND THE MANIPULATION OF RUBBER. - - - - -CHAPTER I. - -THE SOURCES OF INDIA RUBBER AND ITS HISTORY. - - -India rubber or caoutchouc is a very peculiar product, which is found -in and extracted from the juice of certain trees and shrubs. These are -quite numerous and are referred for the most part to the following -families: Euphorbiaceæd, Urticaceæd, Artocarpeæd, Asclepiadaceæd, and -Cinchonaceæd. It is evident that a considerable number of trees are -utilized in commerce for its production, and it is certain that it -exists, quite widely distributed, in many cases as a constituent of the -juice of plants not recognized as containing it. - -When an india rubber tree is tapped, which is effected by making -incisions in the bark, the sap of the tree exudes. It is a milky -substance and is collected in various ways; it may be in vessels of -clay, in shells, or in other receptacles by the india rubber hunters. -If this substance is examined it is found to be of very remarkable -and characteristic constitution, resembling in its physical features -ordinary milk. It is composed of from fifty to ninety per cent. of -water, in which is suspended in microscopic globules, like the cream -in milk, the desired caoutchouc or india rubber. If the juice is left -to stand in vessels, like milk in a creamery, the globules rise to -the surface, and a cream of india rubber can be skimmed off from the -surface. If the juice is evaporated over a fire, the water escapes -and the india rubber remains. By dipping an article repeatedly in the -juice and drying it, a thick or thin coating of india rubber can be -developed. Before the modern methods for the manipulation of the gum -had been developed, and before the invention of vulcanization, this -method was adopted for the manufacture of shoes. The original “india -rubbers” for protection of the feet in wet weather were made in this -manner. A clay last was used, upon which the india rubber was deposited -as described. The clay last was then broken out and removed. Great -quantities of overshoes were thus made in South America, and many were -exported to Europe. - -When caoutchouc has once been removed from this watery emulsion, -which for all practical purposes is a solution, it cannot be restored -to the former state of liquidity; it remains solid. It will absorb -a considerable quantity of water, but will not enter again into -the _quasi_ solution or combination. This property of permanent -coagulation, which interferes to a degree with its easy manipulation, -was early discovered. In the last century quantities of the natural -milk were exported to Europe to be used in what may be termed the -natural process of manufacture, because once solidified it could not be -redissolved, and because the manufacturers of those days had not the -present methods of dealing with the apparently intractable gum. - -The natives of South America before the advent of Europeans, were -familiar with the treatment of the juice by evaporation just described -and used to make bottles, shoes and syringes of it for their own use. -The name _Siphonia_ applied to several species of rubber tree, and -_seringa_ (caoutchouc) and _seringari_ (caoutchouc gatherer) in Spanish -recall the old Indian syringes and tubes. - -The gum is now collected for export in many parts of the world. South -and Central America are, as they have always been, the greatest -producers. Some is collected in Africa, Java and India. The best comes -from Para. However carefully treated a great difference is found in the -product from different countries. The Brazilian india rubber, known as -Para, from the port of shipment, ranks as the best in the market. - -Its history as far as recorded, does not go back of the last century. -Le Condamine, who explored the Amazon River, sent from South America -in 1736 to the _Institute de France_, in Paris, the first sample of -india rubber ever seen in Europe. He accompanied the sample with a -communication. He said that the Indians of that country used the gum in -making several domestic objects of utility, such as vessels, bottles, -boots, waterproof clothing, etc. He stated that it was attacked and -to a certain extent dissolved by warm nut oil. In 1751 and 1768 other -samples were received through MM. Fresnau and Maequer, who sent them to -the Academy of Sciences, Paris, from Cayenne in Guiana. - -Although from this period numerous experiments were tried with the new -substance little of importance was done with it for many years. Its -first use was to rub out pencil marks, whence it derived its name of -“india rubber.” As late as 1820 this continued to be its principal use. - -An interesting reminiscence of its early history is given by Joseph -Priestley, the great English chemist of the last century, celebrated -as the discoverer of oxygen. In 1770 he mentioned the use of the gum -for erasing pencil marks, and speaks of its cost being three shillings, -about seventy cents, for “a cubical piece of about half an inch.” - -As we have seen, its solubility was early studied. In 1761 Hérissant -added turpentine, ether and “huile de Dippel” to the list of solvents. -In 1793 its solubility was utilized in France by Besson, who made -waterproof cloth. In 1797 Johnson introduced for the same manufacture -a solution in mixed turpentine and alcohol. - -The year 1820 is the beginning of the period of its modern use on a -more extended scale. Nadier developed the methods of cutting it into -sheets and threads and of weaving the latter. Mackintosh in 1823 began -the manufacture of waterproof cloth, using the solution of the gum in -coal tar naptha, which was caused to deposit by evaporation a layer of -the gum upon a piece of cloth which was covered by a second one. This -protected the wearer from the gummy and sticky coating of raw india -rubber. At the best the original Mackintoshes must have been very -disagreeable articles for wear. - -In 1825 india rubber shoes of raw india rubber were imported from South -America and formed for a while an important article of commerce. - -In 1839 Charles Goodyear, of Massachusetts, invented the art of -vulcanizing, or combining india rubber with sulphur. It was patented -on June 15, 1844, and covers only the manufacture of soft rubber. -Vulcanite or hard rubber (whalebone rubber) is disputed as to its -origin, its invention being assigned by some to Nelson Goodyear and by -others to Austin G. Day, of Connecticut. Goodyear however succeeded in -obtaining a patent on May 6, 1851. Day obtained a patent on August 10, -1858. - -Vulcanization is the most important invention ever made in connection -with india rubber and may fairly rank as one of the greatest -discoveries of the present century. It is claimed by the English, an -inventor named Handcock being cited as the rival of Charles Goodyear. -The latter inventor had as an associate Nathaniel Hayward, who is -probably entitled to some of the credit. - -By vulcanization india rubber loses susceptibility to heat and cold, -becomes non-adherent, and insoluble in almost all substances. It is -converted from a comparatively useless substance into one of wide -applicability. - -The subject of india rubber is so interesting in its theoretical as -well as practical bearings that it seems impossible that those who -are workers in it should not feel an interest in its natural history. -For such readers the chapter on the natural history and collection of -india rubber has been written. As it is a product of widely separated -lands on both hemispheres, and as it is yielded by an immense number -of plants, it is impossible in the limits of a chapter to give a full -outline of its natural history. - -The chapter in question is, therefore, with this apology, inserted -where it belongs, near the beginning of the book. Those who are -entirely practical may pass it over. There is no doubt that the few -minutes necessary for its perusal will be bestowed upon it by some. - - - - -CHAPTER II. - -THE NATURAL HISTORY AND COLLECTION OF INDIA RUBBER. - - -African india rubber is mostly exported from the west coast. The belt -of country producing it extends nearly across the continent. Those -who are familiar with the india rubber plants of our conservatories -are apt to think of the gum as the product of trees, but in Africa -it is largely yielded by climbing plants of very numerous varieties, -belonging generally to the Landolphia species. It is collected by -the natives by careless or desultory methods, probably less advanced -than the ways followed by the South Americans. Possibly its marked -inferiority may be partly attributed to this. It is also supposed by -many that, were the gathering restricted to the vine producing the -best gum, better results would follow. As it is now all gums are mixed -indiscriminately. African gum is of very inferior quality. - -The African india rubber vines grow often in dark moist ravines, where -no valuable product other than themselves could be cultivated. They -are entirely wild. The vines when cut exude an abundance of sap, -which differs from the South American product in its quickness of -coagulation. As it escapes from the wound it at once solidifies and -prevents the further escape of juice. The negroes are said to employ -the following highly original method of collecting it. They make long -gashes in the bark. As fast as the milky juice comes out they wipe it -off with their fingers and wipe these in turn on their arms, shoulders, -and body. In this way they form a thick covering of inspissated juice -or caoutchouc over the upper part of their body. This from time to -time is removed by peeling. It is then said to be cut up and boiled -in water. This is one account. According to others the natives remove -a large piece of bark, so that the juice runs out and is collected in -holes in the earth or on leaves. Wooden vessels are said to be used -elsewhere. Sometimes the juice is said to be collected upon the arms, -the dried caoutchouc coming off in the shape of tubes. A clew to the -inferiority of African india rubber is afforded by the statement that -too deep a cut liberates a gum which deteriorates the regular product -if it mixes with it. The drying of the gum is thought to have much to -do with its quality and it is highly probable that this affects the -African product. Some samples seem to be partly decomposed they are -so highly offensive in odor. The South American rubber is often dried -in thin layers, one over the other, by a smoky fire, which may have -an antiseptic effect upon the newly coagulated caoutchouc. No such -process as far as known is used in Africa. - -The African india rubber appears under different names in commerce. -From the Congo region lumps of no particular shape called “knuckles”; -from Sierra Leone smooth lumps, “negro-heads,” and “balls” made up -of small scrap; from the Portuguese ports “thimbles,” “nuts,” and -“negro-heads;” from the gaboon “tongues;” and from Liberia “balls” -are received. It is all characterized by great adhesiveness and low -elasticity. - -From Assam, Java, Penang, and Rangoon there is considerable gum -exported. It is supposed to be the product of trees of the _ficus_ -species, in all these places, as it is known to be in Java and Assam. -In the latter place rigid restrictions are imposed as far as possible -upon the gathering. In the case of wild trees scattered through the -forest the carrying out of these restrictions is not practicable. The -trees are cut with knives in long incisions through the bark and the -juice is collected in holes dug in the ground, or often in leaves -wrapped up into a conical form, somewhat as grocers form their wrapping -paper into cornucopia shape for holding sugar, etc. - -It has seemed reasonably certain that the india rubber producing plants -might be cultivated with profit, and it is as certainly to be feared -that without such cultivation they will become extinct. Efforts have -been made in the direction of raising them artificially but without -much success. In Assam numerous experiments have been made to propagate -the india rubber bearing _ficus_ tree. - -A good instance of the ill effects of carelessness in the original -gathering of the crop is afforded by the Bornese collectors. The source -of Borneo india rubber is a variety of creepers. These are cut down and -divided into short sections from a few inches to a yard in length. The -sap oozes out from the ends. To accelerate its escape the pieces are -sometimes heated at one end. It is coagulated by salt water. Sometimes -a salt called _nipa_ salt, obtained by burning a certain plant (_nipa -fruticans_), is used for the purpose. In either case it is coagulated -into rough balls and masses. These masses are heavily charged with the -salt water, often containing as much as fifty per cent., and rarely -much less than twenty per cent. - -[Illustration: TREE FELLED FOR COLLECTION OF INDIA RUBBER.] - -Central America and Panama are great producers of the gum. In Panama -the custom of felling the trees is often adopted. In this case -grooves are cut around the prostrate trunk, and under each groove as -the trunk lies on the ground a vessel is placed to collect the sap. -Its coagulation is often effected by leaving it for a couple of weeks -standing at rest in a hole, excavated on the surface of the ground, -and covered over with leaves. The caoutchouc separates under these -conditions. A quicker method, but one yielding an inferior product, -is obtained by adding to the fresh juice some bruised leaves of a -plant (_ipomæa bona nox_) which acts something like acid upon milk, -in separating the desired solid matter or caoutchouc. A jelly like -accretion saturated with blackish water is thus obtained. By working -it together a blackish liquid is caused to escape, and comparatively -pure gum is gradually obtained. As much as one hundred pounds of india -rubber may be obtained from a single tree where this destructive system -is employed. Further north, where a better counsel has prevailed, the -trees are only tapped, and the india rubber hunter is satisfied if from -a tree eighteen inches in diameter he obtains twenty gallons of sap, -giving fifty pounds of gum. Even where tapping is done the tree is -often destroyed by carelessness or ignorance. - -Two systems are followed in Nicaragua. The operator ascends by a ladder -if he has one, or in any case climbs as high as he well can and begins -to make a long incision. Sometimes he carries one long straight cut -clear down to the ground. This is made the starting point for a number -of side cuts, short, and running diagonally into it. This is also one -of the Brazilian methods. The Nicaraguan sometimes also makes two -spiral incisions, one right-handed and the other left-handed, crossing -each other as they descend so as to divide the surface of the tree -into roughly outlined diamonds. In either case the juice flows down -to an iron spout, placed at the bottom of the tree, which spout leads -to an iron pail. The milk is gathered and passed through a sieve, and -coagulated in barrels by the _ipomæa_ plant as before mentioned. This -gives three grades of rubber. The bulk is obtained from the barrels and -is called often _méros_; the small lump which forms in the spout is -rolled into a ball and called _cabezza_; the dried strips pulled out of -the cuts is of very good quality and is called _bola_ or _burucha_. - -From Brazil is exported the famous Para india rubber. This is of very -high quality, and is greatly esteemed by all manufacturers. No process -can make a poor gum give a really good product. The system of gathering -it varies. Sometimes the tree is cut into by gashes from an axe, such -gashes extending in a row all around the trunk. Under each gash a small -clay cup is luted fast with some fresh mixed clay. These collect from -a tablespoonful of juice upward, which is collected, and the cups are -removed on the same day. The next day a second row of cuts is made -below the others, and the same process is repeated. This is continued -until from a point as high as a man can reach, down to the ground the -tree is full of cuts. Sometimes a gutter of clay is found partly around -the trunk with gashes above it. In other cases a vine is secured around -the tree and a collecting gutter is worked with it for a basis. - -[Illustration: TREE TAPPED FOR INDIA RUBBER.] - -The juice is coagulated in a smoky fire. A bottomless jar is placed -over the fire and some palm nuts are mixed with the fuel. The mould, -which is often a canoe paddle, is smeared with clay to prevent adhesion -and is then heated. A cup of juice is poured over it, and after the -excess has dropped off it is moved about rapidly over the smoke and -hot air which ascends from the mouth of the jar. This series of -operations is repeated until the coating is quite thick; it may be as -much as five inches. After solidifying over night it is cut open and -the paddle or mould is removed. After a few days drying it is sent to -market. With all the heating, during which it sweats profusely, it -still retains fifteen per cent. of water. - -[Illustration: INDIAN DRYING AND SMOKING INDIA RUBBER.] - -India rubber sap may be coagulated by an aqueous solution of alum. The -process has been tried in Brazil, and is used to a considerable extent -in Pernambuco. It was proposed by an investigator named _Strauss_, and -the process is still called by his name. One objection is that it gives -a very wet product, and apparently one of inferior value to the smoked -gum. - -The feeling that india rubber suffers in the gathering has been so -much felt that it has been recently suggested that if possible the -uncoagulated juice should be exported to Europe there to be worked up -from the beginning. - - - - -CHAPTER III. - -PROPERTIES OF UNVULCANIZED AND VULCANIZED INDIA RUBBER. - - -There are two broad divisions to which all varieties of india rubber -can be assigned--unvulcanized and vulcanized rubber. Speaking with -a certain amount of license it may be said that more properties -characterize the former than the latter. The vulcanized article is very -slightly affected by ordinary changes of temperature, cannot to any -considerable extent be changed by heat short of absolute destruction or -decomposition, cannot be united or moulded except in simple forms, is -highly elastic, and is insoluble in almost every solvent for ordinary -caoutchouc. - -Unvulcanized caoutchouc possesses very interesting and peculiar -properties. The first part of the present chapter is devoted to this -substance. Those who have never seen the crude gum as imported are -familiar with the article almost pure in the form of sheet rubber and -black rubber articles generally. These are of nearly pure caoutchouc, -though recently the tendency is to vulcanize them to a considerable -degree. - -A piece of pure gum containing no combined sulphur, iodine, or other -vulcanizing constituent will be found to exhibit a very striking -peculiarity. Two freshly cut surfaces when placed in contact will -adhere. This is not in consequence of any viscous or sticky coating. -When india rubber is cut the surface is perfectly dry and non-adherent -except to itself. - -The writer once had this property of adhesion brought strongly to -his attention. In some analytical investigations of coal gas he had -proposed to use finely divided india rubber as an absorbent of sulphur. -This constituent it absorbs from gas, and it seemed that a basis for a -quantitative determination of sulphur might be found in such property. -Accordingly some raw india rubber was procured and with some trouble -was cut up into little pieces which were put into a bottle. A day or -two afterwards the pieces united wherever they were in contact, and an -irregular cavernous lump was the result. This involved no melting or -softening or change of shape. Each little piece was there intact and -distinct but firmly attached to its neighbors. - -The analogy of this action is seen in lead. Two fresh surfaces brought -together, preferably with a twisting or wrenching pressure, adhere -quite firmly. The adherence of india rubber and of lead each to -itself is often exhibited by physical lecturers as an illustration of -cohesion. The cohesion of india rubber is however far more perfect than -that of lead, probably because of its comparatively great resistance -to oxidation, and because, owing to its elasticity larger areas can -be brought in contact. Comparatively great though this resistance to -oxidation is, oxygen, especially in the allotropic modification known -as ozone, may act quite powerfully on the gum. Sunlight also can affect -it injuriously. - -A more familiar illustration of the uniting of two pieces of the -same material is seen in the welding of iron. The blacksmith heats -two pieces of iron until they are nearly white hot and are pasty in -consistency. On placing them in contact and hammering to force them -together they unite so firmly as to be practically one. It is necessary -that the surfaces of clean metal should be brought together. If the -pressure induced by the hammering is insufficient to bring this about, -a flux is added which dissolves the oxide and causes the metal to come -in contact with metal and to weld. The analogy with india rubber in its -cohesive action is evident. Surfaces long exposed or which are dusty do -not cohere. The relegation of ice is similar in effect. - -The cohesion of india rubber is important and should be thoroughly -appreciated. It is not saying too much to assert that the entire -treatment of the raw gum depends upon this interesting property. The -great lumps of gum are torn to pieces and washed free from gravel and -dirt without going to powder, because owing to their elasticity they -yield and as fast as torn apart the pieces tend to reunite. Again -india rubber is mixed with pigments and vulcanizing reagents by a -method practically one of grinding or masticating, but the material -while it changes its shape, and by the admixture of the various -ingredients becomes less strong or easier torn, still remains intact, -as it welds together or coheres as fast as disintegrated. - -As regards its chemical constitution the sap of a Para rubber tree has -been analyzed with the following general results: (Faraday). - - Caoutchouc 30.70 - Albuminous, extractive, and saline matter, etc. 12.93 - Water 56.37 - ------ - 100.00 - -Its specific gravity is 1.012. - -Caoutchouc itself or raw india rubber is a mixture of several -hydrocarbons of the following composition in general: - - Carbon 87.5 - Hydrogen 12.5 - ----- - 100.0 - -Its specific gravity is from .912 to .942. - -The hydrocarbons composing it are isomeric or polymeric with -turpentine. This fact brings it well within the range of familiar -vegetable products. As will be seen the products of its distillation -fall among the same polymers and isomers. - -When pure it is nearly colorless, the dark color being due to -impurities. In thin sheets it is almost or quite transparent. It burns -readily, and with a very luminous, smoky flame, as might have been -anticipated from its composition. The action of heat and cold on it is -dependent on the degree of the temperature. At ordinary temperature -it is elastic and firm. It can be stretched and will return almost -to its original size when released from tension. Yet the return -to its shape is so liable to be incomplete, especially after long -sustained stretching, that pure unvulcanized india rubber is considered -imperfectly elastic. - -Any elasticity it possesses is principally elasticity of shape as -distinguished from elasticity of volume. In other words when pressed or -stretched it may change shape to a great extent but hardly change its -volume at all. A cube of 2½ inches under a weight of 200 tons lost 1-10 -of its volume only. This is largely due to the fact that it represents -an approximately solid body, or one destitute of considerable physical -pores. Solids and liquids are very slightly compressible. Whatever -degree of compressibility caoutchouc possesses is due principally to -its minute pores. - -If the temperature is reduced to the freezing point of water a piece -of raw india rubber becomes rigid and stiff. On application of heat -it returns to its former pliable condition. The same return to -flexibility may be brought about by stretching it mechanically. This -may be rather a fallacy. Stretching india rubber warms it, so that in -this mechanically imparted rise of temperature we may find at least a -probable cause of the softening. - -If the temperature is raised several effects are produced, according -to circumstances. A piece which has been stretched and held stretched, -has its tension increased by a degree of heat considerably less than -that of boiling water. Some offer the theory that it contains air -enclosed in its pores which, expanding, produces this effect. As the -boiling point is reached the material softens and becomes somewhat -plastic, so that it can be moulded into shape to a considerable extent -and stretched to threads of great fineness. Its elasticity also -disappears as the heat is maintained. These effects increase in extent -up to a heat of 248° F. (120° C.). The return to its original state is -not immediate however. Some time is required before the reduction of -temperature will have full effect. - -If now a still higher degree of heat is applied, 392° F. (200° C.) the -india rubber softens to a viscous body, or melts. From this state it -cannot be restored. It remains permanently “burned” or melted whatever -is done to it. Some attempt at hardening may be made by the use of -vulcanizing chemicals, but the result will be very imperfect. - -A further increase of heat brings about a destructive distillation. -India rubber treated in a retort to a heat exceeding 400° F. (204° C.) -evolves volatile hydrocarbons of oily consistency, and it distills -almost completely, a small residue of gummy matter or of coke if the -final heat has been pushed far enough being left. The distillate is -called caoutchoucin. According to Mr. Greville Williams it consists of -two polymeric hydrocarbons: one, caoutchin C_{10}H_{16}, boiling point -340° F. (171° C.); the other, isoprene C_{5}H_{8} (in formula equal to -one-half of caoutchin), boiling point 99° F. (37° C.). The mixture has -a strong naptha-like odor and has won considerable reputation as being -the best solvent for india rubber. How far it deserves its reputation -is a matter open to discussion. - -The solution of india rubber like its fusion is a vexed point. There is -little question that it can be dissolved by proper treatment. Usually -naptha, carbon disulphide or benzole are used as solvents, the choice -being guided by motives of cheapness and efficiency. - -It is worthy of remark that the formula given for caoutchoucin is -the same as that of the principal constituent of oil of turpentine, -and that the latter is often recommended as a solvent. Turpentine is -slightly more volatile than caoutchoucin, its boiling point being 322° -F. (161° C.) Other hydrocarbons have been recognized in the distillate -by Bouchardat, Himly and G. Williams, varying in boiling point from 32° -F. (0° C.) to 599° F. (315° C.), and in specific gravity from 0.630 to -0.921. - -Although it has been spoken of as approximately solid it does possess -microscopic pores, to which its limited amount of elasticity of volume -is mostly due. Thus it is found to absorb water, in which it is quite -insoluble. As it does this it acts like a dry sponge and increases in -volume a little, owing to dilation of these minute pores. The water -absorbed may be as much as 18.7 to 26.4 per cent. with an increase of -volume of the gum of 15/1000 to 16/1000. When it has once absorbed -water it is very hard to get rid of it. Although the minute surface -orifices communicate with the entire system of capillary vessels and -pores, the surface pores on drying contract and seal up the absorbed -water within the mass. This is a clew to the impracticability of -the gatherer shipping dry rubber, and to the great difficulty the -manufacturer experiences in drying his washed and sheeted stock before -working it up by masticating or mixing and curing. - -By proper manipulation caoutchouc may be made inelastic. This can be -done by the freezing process or by keeping it stretched for two or -three weeks. In this way threads can be made to extend and to remain -extended to seven or eight times their original length. They can then -be woven into a fabric. On gentle heating their original elasticity -reappears and they contract. In this way fluted braids can be made -which will have a high capacity for stretching. - -The solution of caoutchouc is difficult often to bring about. We have -seen that in water it swells a little without dissolving. In benzole -it does the same, but swells to a greater extent, to 125 times its -original volume or even more. Some authorities (_Watts_) go so far -as to assert that no solvent completely dissolves it. Acting on it -repeatedly with benzole or other solvent and taking care not to break -up the swelled mass, from 49 to 60 per cent. of soluble matter can -be extracted. On evaporation this is deposited as a ductile adherent -film. The swelled up residue which remains undissolved is assumed to be -the constituent giving strength and elasticity, and is only sparingly -soluble. If the gum is masticated or kneaded at the temperature of -boiling water a change occurs not well understood, by which its -solubility is greatly increased. As solvents many liquids have been -named. Oil of turpentine, caoutchoucin, coal-tar, naptha, benzole, -petroleum-naptha, coal-tar-naptha, anhydrous ether, many essential -oils, chloroform, bisulphide of carbon, pure, or mixed with seven -or eight per cent. of alcohol, are among the solvents recommended. -A mixture of fifty parts of benzole and seventy parts of rectified -turpentine has been given as a solvent for twenty-six parts of the gum. -Mastication before or after immersion in the solvent is to be advised. -More will be said on this subject in a succeeding chapter. - -Vulcanized india rubber is unaffected by changes of temperature within -ordinary range. It softens a little on heating. Even hard vulcanite -when heated can be bent and will retain the bend on cooling. It is -exceedingly elastic with elasticity of shape but far less compressible -as regards absolute change of volume than the raw gum. It melts at -392° F. (200° C.) It cannot be made to cohere, and no cement has yet -been discovered that will satisfactorily unite two surfaces. It is -unaffected by light, by ordinary acids and rubber solvents. In contact -with the latter solvents it swells sometimes to nine times its original -volume, but on heating returns to its original volume and shape. Of -water it will absorb no more than four per cent. and often much less. -If it is maintained at a high temperature 266° to 302° F. (130° to 150° -C.) for a long time it gradually loses its flexibility, especially -if in contact with metals. Often the escape of sulphuretted hydrogen -may be observed under these conditions. A small admixture of coal tar -operates to prevent this action. - -Its composition and specific gravity vary widely as the most varied -mixtures are added by the manufacturer. Its relation of carbon to -hydrogen is unaffected by the mixtures added. While it may contain -twenty per cent. or more of sulphur it is believed that but a very -small quantity is combined with it, although the excess of sulphur -or some equivalent, such as sulphide of antimony is essential to -vulcanization. The combined sulphur is from one to two per cent. Some -or all of the excess of sulphur is mechanically retained, and as the -rubber in ordinary use is worked about, keeps escaping and forms a -whitish dust upon the surface. By treatment with alkali some of the -excess of sulphur can be removed when the rubber acquires the power of -absorbing a little more water, up to six and four-tenths per cent. - -Boiling oil of turpentine is given as its solvent. - - - - -CHAPTER IV. - -THE MANUFACTURE OF MASTICATED, MIXED SHEET, AND VULCANIZED INDIA RUBBER. - - -The manufacture of india rubber relates to the production of two -principal products. One is masticated unvulcanized sheet and thread -rubber; the other is unmasticated mixed and cured rubber, otherwise -vulcanized rubber. For the purposes of the rubber-stamp maker an -intermediate product is required, namely, unmasticated mixed sheet -which is uncured. This is really incompletely vulcanized india rubber. - -It will be evident from the description to come that it is not -advisable for any one without considerable apparatus to attempt to -clean and to wash (“to sheet”), to masticate, or to mix india rubber. -These operations are best accomplished in the factories. The partially -vulcanized (“mixed sheet”) or the pure masticated article are regular -articles of commerce. Yet a full insight into the manipulation of india -rubber can only be obtained by understanding its treatment from the gum -up to the two separate lines of products we have indicated. - -A third type of product is coated tissue, such as Mackintosh. This -really is a sequence of one of the other two processes and a few words -will be said of it in concluding the chapter. - -As the caoutchouc is received by the manufacturer it appears an -utterly intractable mass. It occurs in lumps of every size, varying in -color and odor, and very tough but elastic. In virtue however of the -properties already described, its power of cohering when cut, and its -softening when heated, it becomes amenable to treatment. - -It is to some extent received in such assorted condition as to secure -even grades, and then each grade may be washed by itself. It is -thrown into water which is in many cases kept at the boiling point by -steam-heat and left there for some hours. It absorbs some water and -also softens. Some gum is so soft that it will not stand hot water. For -such the water is kept cold. The purer gum floats; such pieces as have -stones, dirt, iron, etc. in them, perhaps placed there purposely from -fraudulent motives, sink and can be picked out for separate treatment. - -The lumps are next cut up. A revolving circular knife driven by power -is often used, and sometimes an ordinary knife is adopted. At this part -of the operation there is frequently need for sorting, as the grades -received may have inferior pieces mixed with the good. The cutting is -mainly to secure good grading, and to remove concealed impurities. The -gum then goes to the washing rollers, called the washer and sheeter. -(See cut, p. 37.) - -[Illustration: WASHER AND SHEETER.] - -These are heavy corrugated rolls made very short, 9–18 inches in -length, to prevent springing. They are grooved or corrugated and have a -screw adjustment for regulating their distance apart. They are geared -together so as to work in corresponding directions, like a clothes -wringer or a rolling mill of any kind. The pieces of gum are fed into -the rolls and are drawn between and through them. The friction tends -to heat the gum. To prevent this and also to effect the washing, a -supply of water, either hot or cold, is kept playing upon the mass. -This dissolves out all soluble matter and washes away mechanically the -chips, dirt, etc. which may be present. The whole operation is one of -main force. The caoutchouc is torn and distended and delivered as a -rough perforated sheet. It is passed repeatedly through the machine, -the rollers being gradually brought closer together, or else different -sets of rolls are used, set to different degrees of fineness. The -wash water passes through a screen which catches any small detached -fragments of gum. - -Other types of machines have been introduced; the above is a -representative form. - -The rough sheets must now be perfectly dried, as water impairs the -final product. This is done in drying rooms by steam heat, generally, -at a temperature of about 90° F. (32° C.) The windows, if there are -any, are painted to exclude sunlight, which operates to deteriorate raw -gum. When absolutely dry the caoutchouc is removed and stacked away for -use. - -[Illustration: MASTICATING MACHINE.] - -To prepare pure gum for the manufacture of sheet rubber and as a -starting point for many other preparations, the india rubber is -“masticated” in special apparatus. The machine consists of a fixed -cylinder within which is a corrugated roller set eccentrically and -rotated by power. The perfectly dry sheets in the masticator are -pressed and rolled and ground and produce a mass of even consistency. -Here the welding or cohering action again appears in its fullest -development. The perfect dryness of the mass enables it to keep -reuniting as fast as divided. The action is assisted by the heat -generated, which is not inconsiderable. Sometimes the caoutchouc is -warmed before introduction, and sometimes the roller is heated by -passing steam through it. - -[Illustration: MASTICATING MACHINE.] - -The masticating machine the French picturesquely term the wolf (_loup_) -or devil (_diable_). It is given from sixty to one hundred turns a -minute, and a machine large enough to treat fifty pounds of gum in a -charge, requires five horse-power to drive it. In it the sheeted gum is -ultimately brought to the state of a perfectly homogeneous dark brown -translucent mass. - -The masticated rubber is peculiarly amenable to mechanical and chemical -treatment. It can be shaped by heat and pressure, and it is the most -soluble form and is used for making cement and solution, and is moulded -into blocks for the manufacture of sheet and thread rubber. In the -process neutral body pigments, such as oxide of zinc, or soluble -transparent ones, such as alkanine may be introduced; easily decomposed -matter cannot be incorporated on account of the heat. - -In all these machines special provision is made to prevent any oil from -getting into the gum. There is no greater enemy to india rubber than -oil or fats of any description. The flanges in the masticator that roll -just inside the bearing are for this purpose. - -Sheet rubber is made from the blocks of masticated gum by slicing. A -machine is used for the purpose which carries a knife which works back -and forth in the direction of its length at high speed, making two -thousand cuts a minute. The knife is kept wet by a stream of water, -and about sixty cuts are made per inch. In many articles made from -this sheet the marks of the cuts can be seen as a fine ribbing. The -appearance is familiar to many readers. - -The sheet is often cut from rectangular blocks, but cylindrical blocks -are also used. The latter are rotated in front of the knife edge and a -long, continuous sheet can thus be obtained. - -The sheet rubber can be cut into threads on webbing and braid. Everyone -has noticed that these threads are usually square. The method of -preparation accounts for it. Vulcanized sheet is now almost universally -used for threads. - -Round threads however can be made by forcing softened or partly -dissolved gum through a die. - -It is from unvulcanized masticated sheet that toy balloons, tobacco -pouches, etc., are made. It is the starting point for india rubber -bands. For the usual form of the latter article the sheet is cemented -into a long tube which is afterwards cut transversely, giving bands -of any desired width. To make any of these articles satisfactory -vulcanization is imperative. Unvulcanized rubber for many years was -used, but it is now completely displaced by the vulcanized product. -Sheet rubber is made as above; is vulcanized by some of the absorption -processes described in the chapter on vulcanization. - -We now come to the second product: regularly mixed and cured rubber. -Its starting point is the washed india rubber from the washer and -sheeter. - -We have seen that the pure gum or caoutchouc is very sensitive to -changes of temperature. At the freezing point of water it is hard and -rigid, and at the boiling point is like putty in consistency. There -are several substances which can be made to combine with the gum and -which remove from it this susceptibility to change of temperature. The -process of effecting this combination is called vulcanization, and the -product is called vulcanized india rubber. Sulphur is the agent most -generally employed. - -[Illustration: MAKING MIXED RUBBER.] - -In the factory the normal vulcanization is carried out in two steps, -mixing and curing. The washed sheet india rubber which has not been -masticated and which must be perfectly dry is the starting point, and -the mixing rolls shown in the cuts are the mechanism for carrying out -the first step. These are a pair of powerful rollers which are geared -so as to work like ordinary rolls, except that one revolves about -three times as fast as the other. They are heated by steam, which is -introduced inside of them. The sheet is first passed through them a few -times to secure its softness, and then the operative begins to sprinkle -sulphur upon it as it enters the rolls. This is continued, the rubber -passing and repassing until perfect incorporation is secured. About ten -per cent. of sulphur is added, and a workman can take care of thirty -pounds at a time. - -This material is incompletely vulcanized. It is in its present -condition very amenable to heat and is ready for any moulding process. -Generally it is rolled out or “calendered” into sheets of different -thickness from which articles are made in moulds by curing. - -These sheets are of especial interest to the reader as they are the -material from which most small articles are made, including rubber -stamps. - -This rolling of the mixed india rubber into sheets of definite -thickness is done by special calendering rolls. The product is termed -“mixed sheet.” - -In the mixing rolls the incorporation of other material is often -brought about. Zinc white, lead sulphide, antimony sulphide, chalk, -clay, talc, barium sulphate, plaster of paris, zinc sulphide, lead -sulphate, white lead, oxides of lead, magnesia, silica, form a list -of ordinary mixing ingredients. These lower the cost of the finished -material and are often serious adulterants. For some cases the addition -if not carried too far is not injurious, or even may be beneficial. A -proper admixture renders the gum more easily moulded and treated in the -shaping processes. - -[Illustration: MIXING ROLLS.] - -The next step in the vulcanizing process is the heating of the mass, -which step is called “curing.” Up to a temperature in the neighborhood -of that of boiling water the mixed rubber can be heated without change -except as it is softened. But if the heat is increased it begins to -get a little more elastic and less doughy, and eventually becomes -“cured” or vulcanized. The temperature for vulcanization is about 284° -F. (140° C.). The word “about” is used advisedly, for it is not only a -question of heat but of time of exposure. After vulcanizing, including -the curing, india rubber cannot be moulded to any great extent. In the -manufacturing process, therefore, it is before curing placed in the -moulds, heated, shaped by pressure, and by exposure to a higher heat -in a steam oven called a vulcanizer, is at once cured. - -To prevent adherence to the moulds they are dusted over with ground -soapstone, and the rubber itself is often thus coated. - -The methods of vulcanization and curing, which may be of special use to -the reader, are given in the chapters devoted to that subject (chapter -XI.), and in the one devoted to rubber stamps. - -Hard rubber, termed ebonite when black, and vulcanite when of other -colors, is simply vulcanized rubber containing a large percentage of -sulphur added in the mixing process. - -The manufacture of coated tissues is effected in several ways. The -following is a typical process. A mixture of one part washed and -sheeted india rubber with one part zinc white, one fourth part sulphur, -and about one third part naptha is mixed into a dough-like mass and is -spread upon the cloth by machinery. The latter is simple. It consists -of a bare board arranged to move under a scraping bar. The cloth is -placed on the board and carried under the bar. The coating mixture is -fed on one side of the bar upon the surface of the cloth. As it passes -under, a regulated amount, according to the set of the bar, adheres. It -is then dried by steam heat and recoated, until ordinarily six coats, -each about one one-hundredth of an inch in thickness, have been given. -Three coats are given in each direction with intermediate drying. The -fabric is then cured by heat in vulcanizers. - -Sometimes the sulphur is omitted from the mixture and cold curing, as -described later, is adopted. When the goods are made up the seams are -secured with rubber cement, a thick solution of masticated gum. Such -seams have to be vulcanized. - -Sometimes two such fabrics before curing or vulcanization, are placed -face to face and allowed to adhere and are then cured or vulcanized. - -Enough has been said in this outline of the manufacturer’s treatment -of india rubber to show that the first treatment requires machinery. -Very little can be done with mortar and pestle, although in making up -solution these simple instrumentalities are available. As a starting -point for making small articles masticated sheet rubber and mixed -sheet rubber are the staple materials. The preceding steps are best -accomplished in the factory. - - - - -CHAPTER V. - -INDIA RUBBER STAMP MAKING. - - -We have seen that india rubber cannot be cast in moulds. Except in -special cases deposition from solution is not available. It has to -be shaped by a combination of heat and pressure. When gently heated -it softens and can be pressed in a mould. As it cools it retains the -shape thus given and is moulded. This applies to all unvulcanized india -rubber. If mixed rubber is moulded and heated to a higher temperature -without removal from the mould the curing process is brought about and -the rubber may be not only moulded but cured and the product is moulded -vulcanized india rubber. The mixed sheet whose manufacture is described -in chapter IV. (page 42) is the starting point in rubber stamp making. -It is made for this purpose by the manufacturers. - -When the material is examined it looks like ordinary white india -rubber, being firm in texture and quite strong. On heating to 280° F. -to 290° F. (137° C. to 143° C.) it begins to become “cured,” and if in -a thin sheet one to ten minutes are sufficient for the process. As the -heat is applied the india rubber first softens and becomes much like -putty. It can now be pressed through the smallest orifice and will fill -up the finest details of anything it is pressed against. It is at this -point that pressure must be applied to drive it into the interstices of -the mould. - -As the heat continues it begins to lose its doughy or putty-like -consistency. This marks the reaction of the vulcanizing materials. -They gradually combine with and change the nature of the caoutchouc. -The rubber while still quite soft is elastic. If pressed by the point -of a knife it yields, but springs back to its shape when released from -pressure. The india rubber is vulcanized. - -On removal from the mould it will be found to reproduce its smallest -detail. The color and appearance have not changed much, but its nature -and properties are now those of vulcanized rubber. It is unaffected by -heat or cold within ordinary ranges of temperature, and if the india -rubber is of good quality and made by a proper formula it will last for -years. - -[Illustration: SIMPLE VULCANIZING PRESS FOR RUBBER STAMPS.] - -The first thing to be described is the mould, which includes the -arrangements for pressing the sheet of india rubber while heated. A -small press is needed for this purpose. It may be of the simplest -description, and as an example of a home-made but perfectly efficient -one the illustration may be referred to. The base of the press is a -piece of iron, if heat is to be directly employed. Where a chamber -vulcanizer is used both base and platen may be of wood. But from every -point of view iron is the best. It lasts forever, admits of direct -heating, and does not split, warp, or char. Through two holes drilled -near its opposite sides two ordinary bolts are thrust. It is best to -use flat headed bolts, and to countersink a recess for the heads in -order to keep the bottom level. The heads may need to be filed off -so as to reduce their thickness, in order to secure this object. The -bolts may be soldered in place. One thing should be carefully watched -for--the bolts should be set true so as to rise vertically from the -plane of the base. - -The platen is best made of iron, cut of the shape shown. This is an -excellent disposition of the screw-bolt slots, as by swinging the -right end of the platen back it can be taken off without removing the -nuts and lifting it over the ends of the screws. Besides the two nuts -fitting the thread of the screws it is well to have half a dozen extra -ones larger than the others, which will slip easily over the bolts, -so as to act as washers. The object of these is to adapt the press to -objects of different thickness. The thread upon an ordinary bolt does -not extend clear to the head, but by slipping on some loose nuts the -plates can be forced together if desired. - -This press can be simplified. Both base and platen can be made of wood, -the platen being simply bored for the bolts, and the latter driven -tightly through the holes in the base so as to retain their place. -Even this can be improved on as regards simplicity. Two blocks of wood -screwed together by two or more long wood screws may be made to do -efficient work. - -One trouble is apparent with all these devices, and that is the want of -parallelism of the opposed planes. The base and platen may be true and -parallel or they may not. Perhaps the simplest way of securing this is -the best. It consists in placing across the base two distance pieces, -which may be slips of wood. These must have perfectly parallel faces. -As the press is screwed up they will be gripped between the platen and -base and will not only ensure their parallelism but will keep them at -an exact distance apart. Such distance pieces are shown in the same -cut. Pieces of printers’ “furniture,” spaces, or “quads,” may be used -for this purpose. They should not be fastened in place if there is need -to adapt the press to more than one thickness of material and matrix. - -The above described apparatus is a vulcanizing press. A further -improvement in it may be effected by the use of spring pressure. Two -strong spiral springs may be dropped over the bolts, the nuts being -screwed on above them, or a powerful spring of flat brass or steel -ribband bent into the shape of a shallow letter V may intervene between -nuts and platen, the centre of the bend bearing against the centre of -the platen. - -As regards the strength of the springs there is this to be said. The -distance pieces will prevent a spring that would ordinarily be too -powerful from doing any harm. Such distance pieces should be used, as -the springs must be based upon giving a pressure of many pounds per -square inch of surface to be acted on. They should have a range of an -eighth of an inch or more. The greater the range the more evenly will -they work. - -The next cut shows an excellent little screw press, that is made for -the purpose of pressing vulcanizing flasks. This is so simple that it -will suggest to the mechanical reader how he can make a single-screw -press, which is by far the most convenient to use. In the stationery -stores very small model cast iron copying presses designed for use as -paper weights are sold. They are excellent for a limited amount of -small sized work. - -[Illustration: VULCANIZING FLASK CLAMP.] - -A large sized gas heated press, such as made for the purpose of -manufacturing rubber stamps, is shown in the next cut, p. 53. Its -construction is obvious. It is termed by the trade a vulcanizer. Its -manipulation will be given further on. - -Type are generally the object to be copied. These are best set up with -high quads and spaces. Naturally rather a large type is chosen, with -extra wide spaces between the letters. Some advise rubbing the type -faces full of hard soap, afterwards brushing off the face, leaving the -hollows filled. Sometimes wax is recommended for the same purpose. -This prevents the plaster of the matrix entering so deeply into the -cavities of the letters. - -[Illustration: GAS-HEATED STAMP VULCANIZER.] - -The type forming the model to be reproduced, is locked in a frame. Two -pieces of printers’ furniture or other wooden strips screwed together -by wood screws at their ends will answer for a locking frame for small -inscriptions. - -The model to be copied need not be type, but any desired relief may be -used, such as an electrotype, a stereotype, an engraving or another -rubber stamp. In any case it is to be placed upon a flat surface, best -an “imposing stone” or piece of marble, with the inscription upwards. -On each side of it distance pieces reaching about one-eighth inch above -its upper surface are to be placed. - -The next shaping appliance is the matrix or mould, or reverse of the -model which is to be copied. This in the case of rubber stamps is -properly called the matrix. Those who have witnessed the stereotyping -of a large daily newspaper have seen the matrices of the type made of -paper and paste, the whole mixture being termed “flong.” Such a matrix -is required for rubber type, but paper is rather too susceptible to -heat although good work can be done with it. It also does not enter -as deeply into the cavities of the type as is desirable. As a rule a -fine quality of plaster of paris is to be recommended. What is sold as -dental plaster is the best, but common plaster can be used. It is mixed -with water or with a solution of gum arabic or dextrine in water. For -the latter enough gum should be added to make the mixing solution as -thick as thin syrup. - -A piece of iron, perfectly flat and true, is now to be taken, large -enough to more than cover the inscription to be copied. Upon its -surface a putty made of the plaster and the liquid used in mixing is to -be spread. This should be rather stiff. The surface of the iron should -not be too smooth as it is desirable that the plaster should adhere -well on setting. The plaster should be smoothly spread to a depth of -three-sixteenths or a quarter of an inch. It is best applied with a -palette knife or trowel, although a table knife will answer perfectly. -If its surface does not become smooth it can be made so by applying a -little of the solution with the knife or trowel. - -Before this has been done the model must be oiled. Olive oil or other -clear oil is applied to all parts of the type faces, and the excess -is then wiped off and cleared out of the interstices with a piece of -blotting paper. - -Next the plate with the plaster is inverted and is pressed steadily -down upon the model until it strikes the distance pieces. It is left to -set. In about ten minutes it can be raised, when it will be found to -give a beautiful impression true to the smallest detail of each letter. - -It has been said that water may be used as the mixing fluid. If this -is done it is well to strengthen the mould by saturating it with an -alcoholic solution of shellac, after it has dried thoroughly, best -for a few hours in an oven. This operates to strengthen the small -projections that are liable to crumble or to break off in use. - -The dealers in rubber stamp supplies sell a lever press for conducting -the operation of producing the matrix. The type is locked in a special -chase, which is carried on a bed that travels under and out from under -the platen of the press upon rollers. From each corner of the chase in -which the type model is locked, a pin rises which is encircled by a -spiral spring. A square frame of flat iron with holes at the corners -for the pins to pass through, rests upon these springs well above the -type. The pins pass through holes in its corners. The matrix plate -with its coating of plaster is placed upon this frame, which supports -it above and not touching the type. The whole is now rolled under the -press and the lever pulled to produce the impression. As the pressure -is released the frame with the matrix is raised from the type by the -action of the springs. This can be done immediately, and before the -plaster has set. It is almost impossible to raise it by hand with the -requisite steadiness. The same chase with corner pins and springs can -be used in a screw press, the one press answering for making the matrix -and for moulding and curing the stamps. The plaster matrix can also -be made by casting from a thinner mixture of plaster and water. After -the type has been set up, or the model has been selected and placed -face up and horizontal, a little ridge or projection must be made all -around it. Paper can be pasted around it, and wound with thread for -this purpose. It is oiled and wiped off as before. The plaster is now -mixed with water to the consistency of cream, and is poured upon the -model until it lies even with the projecting ledges or paper border. In -an hour or less it can be removed. If water is used the mould should -before use be treated with shellac solution as already described. The -plaster may also be mixed with gum arabic solution, or with three -to ten per cent. of powdered marshmallow root. This increases its -toughness. - -What is known as the oxychloride of zinc cement appears to the author -to be far preferable to common plaster of paris. It is a trifle more -expensive, but it costs so little that it is well worth trying. It -is made by mixing oxide of zinc with a solution of zinc chloride. No -particular strength of solution or proportions are prescribed; the zinc -chloride solution should be a strong one, and the mixture should be of -about the consistency of soft putty. - -Zinc chloride may be bought as a solid substance or in strong solution. -The latter answers for the mixing directly. It may also be simply -made by dissolving metallic zinc in strong hydrochloric acid. The -manipulation is exactly the same as with plaster of paris. - -The manufacture of papier maché and of other matrices is given in -a special chapter. For all ordinary purposes the plaster or cement -matrices are ample. - -The stamp is made from the mixed uncured sheet rubber, whose -preparation in the factory, including the operation of calendering it -into sheets, has already been described. The best advice the reader can -be given is not to attempt to make it except as a matter of interest -and experiment. It can be purchased especially prepared for stamps from -the dealers in india rubber. - -A piece is cut from the sheet large enough to cover the face of the -matrix. It should have a perfectly smooth surface, without cloth -wrapper marks sometimes found impressed on it. The sheet as received -from the maker is about one-eighth of an inch thick. It is thrown into -a box of powdered soapstone or talc to secure a coating of the same on -both sides. A little is dusted over the matrix and the excess is blown -off. The matrix is now placed upon the base of the press, and heat is -applied. - -To carry out the process most simply the press if of metal may be -placed upon a support over a gas burner or kerosene lamp, or even on a -kitchen range or stove. It will in a few minutes become warm. The sheet -of india rubber is now dusted off and is placed in the press upon the -matrix. The platen of the press is screwed down upon it. - -As the india rubber becomes hot it begins to soften and flow. By the -action of the screw of the press it must be forced down from time to -time as it softens. This drives the putty-like material into all the -interstices of the mould. The excess escapes from the sides of the -tympan in cases where the latter is of restricted area. The press -theoretically should be heated to the vulcanizing temperature, which -is 284° F. (140° C.). In practice the heat is not determined with a -thermometer. The operator learns by experience how much heat to apply. -The regulation type of gas heated press or stamp vulcanizer is shown in -the illustration on page 53. - -As some of the india rubber is sure to protrude, the progress of the -work can be watched from its action. By pressing the point of a knife -against it the period of vulcanization can be told. Before the material -is heated it is elastic and resists the pressure of the knife; as heat -is applied it becomes soft like putty; as the heat increases it again -stiffens and becomes quite elastic. At this point the press can be -opened and the sheet and matrix can be taken out or the platen swung -aside. On pulling or stripping the sheet from the matrix it will be -found to reproduce the model in elastic india rubber to the minutest -detail. - -[Illustration: OIL STOVE FOR HEATING VULCANIZERS.] - -As regards the minor details there is something to be said. Distance -pieces to gauge the thickness have been recommended for the home-made -press, page 48. Care must be taken to have these low enough to provide -for enough excess of material to produce a good impression. For -ordinary stamp work they should allow about one-sixteenth of an inch -for the “squeeze.” It will be seen that by using the distance or gauge -pieces both for making the matrix and for moulding and curing the -stamp, absolute parallelism of surfaces will be secured. - -The reader will have noticed in the description and will find at once -in practice that the press has to be screwed up as the rubber softens. -Where heavy iron presses are used the large mass of heated iron -comprised in the platen of the press instantly heats the upper surface -of the india rubber sheet and the heat immediately penetrates into it, -while the heated matrix heats it from below. Thus it softens at once, -and the press is directly turned down and the india rubber is driven -into the mould and curing at once begins. But where small presses are -used this manipulation is not so easy. For such the springs mentioned -on page 51, are highly to be recommended. The matrix and india rubber -can be put into the cold press, and the tympan with intervening springs -can be screwed down so as to compress them. Then on applying heat the -moulding takes place automatically. - -With a hot press and good sheet a period of three to ten minutes is -ample for moulding and curing. - -Instead of sprinkling with talc the matrix may be oiled and sprinkled -with plumbago and afterwards polished with a brush. This is not so -clean a material as talc and is not to be recommended for general use, -especially as oil is a bad substance to bring in contact with rubber. - -The distance or gauge pieces whose use has been recommended are not -necessary where presses working truly parallel as regards their -opposing faces are used. But where home-made apparatus is used they -will be found a valuable addition. - -In describing the simple press it was said that it could be made of -wood. It is evident that a wooden press could not be used for direct -heating. Such a press must be used in a hot chamber or vulcanizer, -properly so called. Originally rubber stamps were generally made in -chamber vulcanizers. - -The next cut shows a combined matrix making, moulding and vulcanizing -apparatus of very convenient and compact form and adapted for rapid -work. As the press stands in the cut the matrix press is seen in front. -A box or chase is carried under its platen by two trunnions, so as to -be free to oscillate to a limited extent. The type model is secured in -this box. Above this box or chase is a cross-bar with screw and platen -attached, connected at will to two standards or pillars, so as to -constitute the matrix press. - -A matrix plate swings on a hinge joint between the two presses. The -hinge-pin is removable. Its ends can be seen projecting to right and -left of the press columns. The hinge is at such a height that when the -matrix plate is swung forward over the type box it will rest upon it in -a nearly horizontal position. The pivoted box will adjust itself so as -to come into parallelism with the plate. - -[Illustration: MATRIX MAKING, MOULDING AND VULCANIZING APPARATUS.] - -When the matrix plate is swung back it falls upon the base plate of the -vulcanizing press seen in the rear. - -In use the composition used for the matrix is spread upon the matrix -plate, which may for this purpose be removed from the apparatus. It -is replaced and the hinge-pin is pushed home. This is done with the -composition coated side facing the front of the apparatus as it stands -in the cut. The plate is then swung forwards, the platen of the matrix -press being turned forward out of the way, and is pressed down upon the -type or other model that rests in the type box. If desired the press is -used to force it home. The cross-bars of both the presses are arranged -to swing each one on one of the pillars, so that the platens are turned -to one side out of the way of the matrix plate as it is swung back and -forth. - -The pressure is released and the platens are turned aside. The matrix -plate is swung over to the rear upon the bed-plate of the vulcanizing -press. Here it lies with the composition-matrix upwards. - -A lighted lamp, either alcohol or gas, is placed beneath the bed-plate -of the vulcanizing press on which the matrix rests. This quickly dries -it and brings it to a good curing temperature. The cross-bar and platen -may be swung over it during the heating so as to be heated at the same -time. The matrix is talced when dry and hot; the mixed sheet itself -talced, is placed upon the matrix, the platen is screwed down upon it, -and in a minute or two the moulding and curing is completed. - -[Illustration: RUBBER STAMP VULCANIZER.] - -A vulcanizer, properly speaking, is a vessel arranged to heat to a -definite degree any desired articles which are to be cured. The -favorite type have been the steam vulcanizers. If steam is generated -from water at a constant pressure, other things being equal a constant -temperature will be produced. By raising or lowering the pressure -the temperature can be made to rise or fall. A steam vulcanizer is a -tightly sealed vessel which contains water and which is provided with a -thermometer or a pressure gauge as well as a safety-valve, safety disc -or safety plug. By keeping the gauge at constant pressure or by keeping -the thermometer constant the temperature can be limited and kept -steady. The following table gives some pressure in pounds per square -inch with temperatures corresponding to steam of such pressures: - - Lbs. per square inch. Temp. Fahr. Temp. Cent. - - 45.512 275° 135° - 52.548 284° 140° - 60.442 293° 145° - 67.408 300.2° 149° - -The illustration, p. 64, shows a vulcanizer of modern type made for -rubber stamp work. In some recent vulcanizers the water and steam are -excluded from the vulcanizing chamber, being contained within double -walls forming a steam jacket and maintaining a constant heat within the -chamber. These illustrate a point that has been much misapprehended, -namely that curing is independent of pressure or atmosphere. Because -vulcanizers have generally been filled with steam at high pressure -many have supposed that the steam or pressure had something to do with -their action. The fact is that it is only the heat due to the steam at -such pressure that is instrumental. Steam is a very powerful radiator -and absorber of so called radiant heat. For this reason an atmosphere -of steam maintains all parts of the vulcanizer at an even temperature -and is to that extent advantageous. Its presence and the pressure it -generates are not by any means required for vulcanizing. Its pressure -is entirely without effect. - -[Illustration: STEAM JACKET VULCANIZER.] - -To use a steam vulcanizer, water is introduced, the article in the -press or mould is placed in it, and the top is secured. Heat is then -applied, best if on the small scale, from a Bunsen gas burner gas, or -oil stove. Either the pressure gauge or thermometer may be watched, and -the flame turned up or down to keep it at the proper temperature. - -Moulding cannot be executed in the ordinary closed chambers. The press -must first be heated to the temperature of boiling water or thereabouts -and the moulding is then effected by screwing down the mould screw, -upon the sheet and matrix. It is then placed in the vulcanizer and -cured. - -The manufacturers supply gas regulators which automatically regulate -the gas supply. These are worked by the steam pressure. If any one -wishes to study the practical manipulation of small steam vulcanizers -he can see them in use at any dentist’s office. - -There is no need of a steam vulcanizer for ordinary stamp work. The hot -press system already described answers every purpose and is in use by -the most advanced manufacturers for thin sheet work. But if a wooden -moulding press is used then it must be heated in a vulcanizer or some -kind of oven or hot chamber. - -A very simple and reasonably satisfactory oven or air bath can be -made from a flower pot and a couple of tin plates. A plate larger -in diameter than the mouth of the flower pot forms the base of the -apparatus. This is supported on a stand over the gas lamp or other -source of heat. A smokeless flame or one depositing no lampblack should -be used. Alcohol or a kerosene oil stove illustrated on page 59 are -excellent. On this plate a smaller plate is inverted, which latter must -be so small as to be surrounded by the flower pot and to be included -within it when the pot is placed over it like an extinguisher. - -[Illustration: FLOWER POT VULCANIZER ON STAND.] - -A chemical or round stemmed thermometer is arranged to go through the -aperture in the upturned bottom of the pot. This may be hung from a -support or it may be secured by passing through a hole in a cork or -block of wood. Its bulb should be near the part of the chamber to be -occupied by the mould or press. - -The press with the article to be cured is placed upon the inner plate. -The temperature is maintained at the proper point by regulating the -heat, and all the conditions for excellent work are supplied. The -disposition of the apparatus is shown in the cuts. - -[Illustration: INTERIOR OF FLOWER POT VULCANIZER.] - -Another arrangement equally simple is given in the next cut. An iron -kettle has a layer of type metal or lead poured an inch thick cast -within it upon its bottom. A thermometer passing through a hole in the -cover enters a cup of glycerine that stands upon the bottom. This gives -the temperature. - -The object of having a thick or a double bottom is to prevent excessive -radiation of heat from any one part. The essential condition for good -operation is to maintain an even temperature throughout the chamber. - -[Illustration: FISH KETTLE VULCANIZER.] - -The thermometer is not an absolute necessity. By removing the press -from time to time and inspecting the overflow of india rubber the -progress of the operation can be watched. An extra piece of india -rubber may be placed on a piece of wood by the side of or upon the -wooden portion of the press, and its condition can be taken as the -criterion. Pressure with the point of a knife will tell the vulcanizing -point. - -By the press system of curing, a heat far above the vulcanizing -temperature may be made to do good work by a very short application. -There is however danger of burning the work if left in too long. If -the air-bath with thermometer or the steam vulcanizer is used, and -the heat is kept down to the proper curing temperature, there is no -danger of burning the india rubber even if the curing is considerably -prolonged. - -As the flower pot has often to be lifted off for introduction or -removal of the press, and as it gets quite hot, a holder of some kind -is requisite. A piece of heavy blotting paper is very convenient for -this purpose. - -The flower pot system with thermometer can be further simplified by -being used on a stove or range. A china saucer inverted, or some -similar support, should be placed under the pot. A part of the stove at -very low heat will suffice. The kettle vulcanizer, can also be placed -on a stove so as to dispense with gas or oil. - -Finally, as the last step in simplifying the work, a stamp can be made -without any special apparatus beyond a hot flat iron. The matrix may be -placed on a stove where the heat is rather low, the talc-coated mixed -rubber sheet placed upon it, and on this a hot flat iron. In a few -minutes if the heat is sufficient the stamp will be finished. - -A few words may be said about the type. High spaces and quads between -the letters should be used, such as will come up to the shoulder of the -type, as has been said. But a very nice effect is produced by using -low quads between words. This leaves each word elevated by itself, -producing a good appearance. - -Autograph stamps are made from a model cut in wood by a wood engraver. -The autograph is written in some form of copying ink upon a piece of -paper, and is transferred by moistening and pressure to a block of -wood. With an engraver’s tool the wood is cut away from the lines, as -the block is routed after the inscription has been “outlined.” The -woodcut is used as a model for making a matrix. - -It is evident that an autograph of fair quality could be obtained from -a chalk plate. But in rubber stamp work to get good results certain -essential parts should be of the best. These parts include the mixed -rubber, model and matrix. A departure from excellence in any of these -tends to the production of an inferior stamp. What is known as a -“healthy cure” is above all essential to the appearance of the product. - -The stamp thus made is attached to a wooden handle by common glue or by -one of the rubber cements given in chapter XVI. - - - - -CHAPTER VI. - -INDIA RUBBER TYPE MAKING. - - -India rubber type are often used to set up different inscriptions in -wooden handles, or different date figures in rubber stamps. The latter -are in such cases made with slots or recesses to receive them. Rubber -type are much shorter than regular type, and as a rule are larger in -the body in proportion to the face of the letter. Where only a few are -required the following process is the simplest way of making them from -mixed rubber sheet. - -The type which are to be copied are set up on a level base or imposing -stone, and quads or spaces are put between them. High quads and spaces -should be used; otherwise they should be pushed up until even with the -shoulders of the type. After oiling the faces a matrix is produced -exactly as described for stamps. Before it has set quite hard the -plaster or cement is cut off so that it will just fit within a little -“flask” or frame. - -The latter may be made of tin or wood and may be rectangular or -circular, provided it is large enough to include within its area the -full working face of the matrix. It should be about half an inch or -five-eighths of an inch deep. Its object is to prevent the softened -india rubber from spreading, so as to secure the requisite height of -the type produced. - -[Illustration: INDIA RUBBER TYPE MOULD.] - -A piece of wood or metal is cut so as to fit closely within this frame -like a plunger. It is provided with shoulders or cross pieces, so as -to limit the depth to which it can be inserted. It will be seen that -when matrix, flask, and plunger are all put together a complete mould -for a block of type is produced, as shown in the illustration, the -matrix with its plate forming the bottom of the box. After the flask is -placed upon the matrix it is filled with the mixed uncured india rubber -sheet. As a matter of preference thick sheet is used, but scraps of all -shapes can be employed as it all fuses together. The mould and matrix -are of course first well dusted with talc powder. The plunger is put on -and the whole is pressed. Heat is next applied in a vulcanizer or hot -air chamber, such as the flower pot arrangement, or in boiling water. -As the sheet reaches the boiling point 212° F. (100° C.) the flask is -removed and the plunger examined. If it goes down to its seat without -expelling any india rubber more of the latter is required and is -accordingly inserted, the plunger being taken off for the purpose. The -softened gum should ooze out around the sides of the plunger. The whole -is again put under pressure, and the platen is screwed down, and if all -is right an excess of rubber showing itself, the whole is put in the -hot chamber, the heat is raised to 284° F. (140° C.), and is maintained -there for half an hour. - -It is almost a necessity to secure the matrix plate to the bottom of -the flask. This for a single operation may be done by screws, or for -several operations by hooks or catches. - -When the curing is complete the mould is removed from the vulcanizer, -is allowed to cool and is opened. The block of type will come out -with perfect reproduction of the letters upon one side. If all the -directions have been followed as regards distance pieces, level -imposing surface, etc., both faces will be exactly parallel, and any -number of other blocks can be reproduced of exactly the same height, -not necessarily from the same matrix, although one good matrix can be -used many times. - -The type have now to be cut apart. This is done with a sharp knife -which is kept wet. It is worked with a sawing motion, and if sharp and -properly used will cut with regularity, and smoothly. Type with knife -marks on the sides are always unmechanical in appearance and seem to be -“home made.” - -The object of using high quads and spaces or of pushing them up, will -now be evident. It secures the evenness of the general face of the -block of letters, which otherwise would have a deep depression between -each pair of letters. If the quads and leads are properly arranged, the -letters will project upwards from a smooth, plane surface. - -The dealers in rubber stamp maker’s supplies sell special steel moulds -for the purpose of making them. This does away with all necessity for -making matrices, and making up a flask, etc. The general manipulation -is that given above. Where many are to be made the regular mould is by -all means to be recommended. - -Sometimes type are made by cementing single letters made by the stamp -process upon wooden bodies. - - - - -CHAPTER VII. - -THE MAKING OF STAMPS AND TYPE FROM VULCANIZED INDIA RUBBER. - - -Although all reference hitherto in the matters of stamps and type has -been to their manufacture from uncured india rubber, a good deal can -be done with vulcanized and cured gum. The stock that is known in the -trade as pure gum, such as is used for bicycle tyres, for steam packing -and the like, can be made to yield to moulding to a certain degree. -It will not flow and unite as will the uncured gum, but it is evident -that in certain cases its stiffness is even an advantage. Thus with it, -rubber type can be made without any flask or frame. The material has -stiffness enough to support itself. - -The manipulation is of the simplest. A piece is cut out with a knife so -as to be of proper thickness and size. It should be a little thicker -than will ultimately be required. The two opposite surfaces should be -smooth and parallel. It is talced, and placed in the press with the -matrix beneath it, and subjected to pressure by the screws being turned -down. It is then placed in the vulcanizing chamber and heated to about -284° F. (140° C.). After it has become hot it softens a little. The -press is removed from the hot chamber and is again screwed down as hard -as the matrix can stand. This point is largely a matter of judgment. -The heat is largely indifferent as long as it is anywhere near the -above temperature. - -By one or two repetitions of the pressing and heating the softened -india rubber can be made to take quite a deep impression from a -suitable matrix. It is allowed to cool under full pressure. When -removed from the press, it will retain the characters. - -It is evident that impressions in as high relief or as deep and clear -as those yielded by uncured india rubber need not be expected. But -where the other cannot be had, or where some experimental or temporary -work only is on hand, this process will be very convenient. - -The material may be half an inch thick. From such india rubber type can -be cut with advantage. - -Old rubber can be thus used. The writer has obtained excellent results -from pieces of an old discarded bicycle tyre. - -The great point is to apply a heavy pressure to the hot material. Many -other articles can be thus produced extemporaneously. At the same time -it must be considered only a makeshift. One who has used the soft, -easy flowing uncured gum would never be reconciled to the use of so -rigid and difficultly moulded a material, one too that can never be -trusted to reproduce intricate moulds of considerable depth. In the -slow yielding of the half melted uncured gum, so amenable to slight -pressure, a quality of availability is found that is missed in the -other. One is worked by main force where the other readily yields and -takes the most complicated shapes. - -By the above process stamps of such thickness may be made that they can -be used without handles. It is also useful for impressing a designation -of any kind upon ready cured articles. It suggests a very useful -department of manipulation of india rubber. - -The heating and moulding can be done also in a hot liquid bath such as -described in chapter XI. - - - - -CHAPTER VIII. - -VARIOUS TYPE MATRICES FOR RUBBER STAMPS AND TYPES. - - -Matrices for stamp moulds can be made by several of the methods used by -stereotypers. Thus an electrotype could be taken directly from the face -of the type. There would be little or no utility in doing this where -the simpler processes are available. - - -PAPIER MACHÉ MATRICES. - -The stereotyper for daily newspaper work uses very generally the -papier maché or “flong” process of reproducing the page. This is also -available for rubber stamp making. - -The first requirement is paste. This is made by softening twelve parts -of whiting in forty parts of water, letting it soak for an hour or -more. Nine parts of wheat flour are added. This is best mixed with a -little water before adding to the main mixture. It is then brought to -the boil and seven parts of glue softened by soaking in twenty-one -parts of water, are added. For each gallon of such mixture, one ounce -of white crystallized carbolic acid is added if it is to be kept for a -long time. - -The “flong” is made by pasting together, one on top of the other, a -sheet of fine hard tissue paper, three sheets of blotting paper (about -23 pounds to the ream), and a heavy sheet of manilla paper. The pasting -must be smooth and each layer must be pressed and rubbed down, but -not too hard. It is very important to secure perfect smoothness and -regularity, and entire absence of air bubbles. - -Every printing office where the process is used has its own -traditions as to the preparation of flong. As a great deal depends on -manipulation, it would be well to endeavor to inspect its practical use -in a newspaper printing office before making it. Ready prepared flong -can also be procured. - -The form of type must be very clean and there must be no paste on -the tissue paper face of the flong. The type are lightly oiled, some -powdered talc is dusted over the damp tissue paper face of the flong, -and the mass is laid face downward on the type. With a stiff haired -brush the paper is now beaten down against the type. Great care must be -taken to beat vertically; a slight side action will ruin the resulting -matrix. If the brown paper will not stand the beating, a cloth may be -spread over it. - -The progress of the work can be watched by raising up a corner from -time to time. When sufficiently deep the last touch is given by the -printer’s planer. This is a block of hard wood. It is placed upon the -back of the flong and is hammered down. The operation is repeated until -the entire area has been treated. For much rubber stamp work the area -would be so restricted that shifting would be unnecessary. - -The work is then put into a heated screw press, such as the vulcanizing -and matrix press, and is dried for a period varying from some minutes -up to half an hour. Some blotting paper is advantageously pressed -on top of the whole in the press while drying. The press is opened, -the flong removed, and dried in an oven. It is kept under a piece of -wire net while drying to keep it flat. The net may be of wire, .064 -inch thick, with six meshes to the inch. This baking is not strictly -necessary for rubber stamp work. - -This gives a matrix which may be used as rubber stamp moulds. In use it -is recommended to place a piece of smooth tin foil over it. This tends -to give a smoother surface to the rubber. - - -STRUCK UP MATRICES. - -Didot’s polytype process may be advantageously used for producing type -metal matrices. The following is the method of applying it. - -The type form is firmly locked and is backed up by and secured to a -solid block of wood. It is suspended in a sort of gallows frame with -the face of the type downward and exactly level a few inches above a -table. Underneath it a shallow tray is placed, into which some melted -type metal is poured. The melted metal is carefully watched. The block -and type are held by a catch so as to be released at will. Just as the -type metal is on the point of solidifying, the block is released and -drops upon the metal in the tray. The type should be slightly oiled. -The force of the blow produces a matrix in the metal, and the form can -at once be removed. - -It is well to have accurately adjusted distance pieces for -corresponding striking pieces on the type block to impinge upon. The -process is highly spoken of, especially for small forms such as those -mostly required for rubber stamps. - - -CHALK PLATES. - -The base for this form of matrix is a metal plate whose surface is -slightly roughened with sand-paper. It is next rubbed over with white -of egg, and flooded with the chalk wash made as follows: Flong paste -(described under Papier Maché Matrices, page 80), six ounces; whiting, -twenty-four ounces; water, three pints. The whiting is softened by -soaking for an hour or more. The whole must be intimately mixed. It -should cover the plate to the depth of one-thirtieth to one-twentieth -of an inch. The plate is dried in a perfectly horizontal position. - -When dry the design or writing, etc., is made with a smooth steel -point, the lines being carried clear through the white layer to the -metal. The mould is now baked at a temperature well above boiling -water; as high as 392° F. (200° C.) may be reached without harm. - -If the coating seems too thin, an extra coat can be given between the -lines especially over the larger areas. This must be done before the -baking. A pipette may be used for putting on this coat. This deepening -has the bad effect of increasing the chance of the coating stripping -from the metal. - -The matrix thus prepared is used in the press just as is the ordinary -plaster matrix. It is suited for reproduction of autographs, scrip, -diagrams, etc. - - - - -CHAPTER IX. - -THE MAKING OF VARIOUS SMALL ARTICLES OF INDIA RUBBER. - - -India rubber can be so readily shaped in moulds and the latter are so -readily made of plaster of paris that any one who is interested in such -things will find endless amusement in working out different designs. -Before suggesting any specific articles the following are the general -points to be kept in mind. - -The material may be uncured mixed sheet of any thickness. As we have -seen this material when heated and pressed runs together. It can be -forced into any shape by comparatively slight pressure. So exactly does -it reproduce the smallest line or mark, that care must be taken to have -the moulds very smooth and free from defect. Powdered soapstone is used -to prevent adherence to the mould, but great care must be taken not to -mix it among the pieces of the india rubber, where several are used in -one article, as it will prevent their coalescing or running together. - -Another point is to contrive to introduce the proper quantity of -rubber. The aim must be to have a slight excess, but to avoid -waste this should be as little as possible. Unless some rubber is -squeezed out there is no certainty that the mould has been filled. -Any projecting “fins” from the overflow are cut off with a knife or -scissors after the article is removed from the mould. - -Plaster of paris or dental plaster mixed with dextrine or gum arabic -water or the zinc oxychloride cement, already described, is to be -recommended for the moulds. They should be made, if deep, in frames or -“flasks” of tin, as plaster if unsupported is liable to split open when -the rubber is forced home. - -For many articles the hot press can be used. Such articles are mats -and other thin flat pieces. The rubber stamp sheet is a good material -for them. For thicker articles a thicker sheet can be used, and sheet -of any gauge can be procured from the maker. Much of what has been -said about india rubber type applies to the making of miscellaneous -shapes. It will also be understood where wooden moulds are spoken of -that plaster, or, still better, metal can be substituted, and is to be -recommended for nice work as the grain of the wood is very apt to show -where the india rubber comes in contact with it. - -Suction discs and similar small articles into which an extra thickness -of india rubber enters are best cured in a vulcanizer. The flower pot -arrangement is excellent for such. The time for curing may be somewhat -extended on account of the greater thickness of material to be acted -on. - -_Suction Discs._--For suction discs a mould is required which will -produce a shallow cup with the edge feathered or reduced to a very -slight thickness. Its outer surface should be raised in the centre -so as to give a projection for attachment of the hook. The discs are -generally made small, not over an inch in diameter, as they are not -reliable for any heavy service. Their principal use is to suspend -advertising cards and light articles to the glass of show windows. The -following is a method of making a simple mould. - -A hole to give the outside contour should be bored in a small piece of -wood. A marble which will exactly fit the hole is next required. Some -plaster of paris is mixed with water and put into the bottom of the -hole, and the oiled marble is pressed down until the plaster rises and -fills the entire space under the marble. After it has set the marble is -removed. The proportions should be so arranged that the plaster will -have risen at the sides within an eighth of an inch of the surface of -the wood. This gives the exterior mould. For the cup or hollow a marble -a shade too large to enter the hole may be used. - -One or if necessary two thicknesses of mixed sheet rubber cut into disc -shape so as to fit the hole are inserted in the block, and the larger -marble is placed on top and screwed down by the press. Heat is now -applied in the vulcanizer. When the thermometer indicates 212° F. (100° -C.), or better a little more, the mould is withdrawn and the screws -turned until the rubber is forced down and the excess begins to squeeze -out between the marble and the wood, which two should now nearly touch. -It is replaced and the heat is brought up to the curing temperature -284° F. (140° C.). It is possible that a second screwing up may be -needed. The spring press is in such cases particularly convenient as -it avoids the necessity for removing the press from the vulcanizing -chamber. After half an hour it will be thoroughly cured. A hole is made -through its centre from side to side thereof, but not penetrating the -disc, and through this hole a brass nail is thrust and bent into hook -form. - -[Illustration: MOULD FOR SUCTION DISCS.] - -In the cut the correct shape for the mould and consequently for a -suction disc is shown. This can be easily secured where a disc already -made is procurable by casting in plaster, or, with a little ingenuity -the template for the mould and the plunger to be used instead of the -marble can be whittled out of wood. The lower body of the mould in such -a case can be made of plaster of paris. To secure the alignment of the -two parts of the mould, dowel pins, indicated in dotted lines, should -be placed near the periphery. The gum should be introduced in a lump -near the centre, in order that it may sink well downwards to the bottom -of the mould before spreading laterally. Sometimes the tips have a -recessed end. This is secured by the use of a mandrel, shown in dotted -lines in the axis of the mould. Such discs are sometimes made to be -cemented to arrows to be discharged against smooth surfaced targets, to -which they adhere on impact by atmospheric pressure, giving rise to a -very interesting game. - -Another use of suction discs is as photographic negative holders. They -can be fastened to a wooden handle and be attached by suction to the -back of a negative under treatment. For this purpose they should be at -least two inches in diameter. - -_Pencil Tips._--These are generally little cylinders of india rubber, -which fit into a tube that slides over the end of the pencil. They can -be thus simply made. A hole is bored in a piece of wood the diameter of -and a little more than the depth of the pencil tip. A short cylinder -that exactly fits the hole is required for plunger. The gum is put into -the hole in little discs, or rolled up into a cylinder, the plunger is -placed on top, and the mould put in the press. It is shaped by pressure -and cured as described. - -Sometimes the tips are cup shaped. For these the mould is made in two -sections fastened by catches or by pins set in the plaster as shown in -the cut. The hole is made larger at bottom than at top, and at the -top is a little smaller than the shaft of the pencil. A plunger that -nearly fits the small end is provided. The india rubber is placed in -the mould and heated. When soft, the plunger is forced down to the -proper distance in the press and the article is cured. Care must be -taken to give the plunger a good coating of talc, and it must be made -to sit vertically. The arrangement of a cylindrical hole shown in the -cut secures this result perfectly. As distance piece a pin is passed -through the plunger. - -[Illustration: MOULD FOR PENCIL TIPS.] - -_Cane and Chair Leg Tips, etc._--By carrying out the process just -described with larger moulds and of slightly different section very -convenient tips for chair legs and walking canes can be made. Such -tips can be modified in size and thickness to answer as covers for the -mouths of bottles, test-tubes, etc. - -_Corks._--These may be made in moulds tapering from top to bottom. -The india rubber must be packed in with great care to secure as solid -filling as possible. A plunger is used that enters the larger end and -is a very little smaller in diameter, so as to descend a little way -into the mould. This distance determines the length of the cork. As the -perimeter of the plunger strikes the walls of the mould it cuts off -almost completely the excess of rubber that has squeezed up past it. An -excellent modification of the mould is shown in the cut. The upper part -with parallel sides serves as a guide for the plunger. It is a similar -extension as the one recommended to be used for the plunger in the -hollow pencil and chair leg tip moulds just spoken of. - -[Illustration: MOULD FOR RUBBER CORKS.] - -_Mats._--These may generally be made in the hot press. Designs for them -in great variety may be found in cut glass and pressed glass dishes. -Many of these have patterns on their bottoms that can be moulded in -plaster to serve as matrices. - -_Cord, Thread and Seamless Tube._--By placing the mixed india rubber in -a cylindrical mould fitted with piston and with one or more round holes -in the bottom, the material may be softened by heat and forced out of -the holes by depressing the piston. This will form cylindrical thread -or cord. As it descends it may be received in a box of powdered talc -and be afterwards cured. By providing the hole with a mandrel seamless -tubing may be thus made. In making such the mandrel usually remains in -place during the curing. Plenty of powdered talc must be used. - -_Skeletonized Leaves as Models._--These would form interesting models -from which matrices could be made in plaster. It would be possible to -produce some very pretty stamps or mats from these and similar models. - -After some experience inspection of any article will show how it was -moulded. The fin will indicate the joint in the mould, and with this as -a clew the mould can be almost certainly constructed like the original. - -_India Rubber Bulbs._--Bulbs and hollow articles generally, such as -dolls, toys and the like, cannot be made without special high pressure -hollow moulds. The general process consists in cutting out gores from -mixed sheet as for a balloon. The edges are coated with cement (thick -benzole or carbon disulphide india rubber solution) and while the -rubber is warm the seams are pressed and knitted together with the -fingers. A hole is left in one place through which some pure water -or water of ammonia is introduced. The bulb is now blown up with the -mouth or otherwise, and while inflated the hole is pressed shut. This -is often done with the teeth. Any projections around the seams are -cut off with curved scissors. The mould is of iron and in two halves. -Powdered talc is applied, and the bulb is placed in and shut up in the -mould which it should exactly fill. The mould is clamped together and -the whole is put into a vulcanizer, and the rubber is cured. The steam -and vapor formed by its liquid contents expand it and press it with -great force against the sides of the mould. After curing the mould and -bulb are removed from the vulcanizer, cooled by a shower bath of cold -water, the mould is opened and the bulb is removed. Often an iron pin -is left projecting through the side during the vulcanizing, which pin, -when withdrawn, leaves the necessary aperture, or it is perforated. The -bulbs are polished by tumbling in a revolving cylinder. Considerable -skill and practice are needed to succeed in making hollow bulbs. Great -accuracy is needed in cutting out the gores and in joining the seams. - - - - -CHAPTER X. - -THE MANIPULATION OF MASTICATED SHEET RUBBER. - - -The manipulation of pure sheet rubber is simple, yet is liable to -lead to disappointment. When two pieces are laid face to face and cut -across with a sharp knife, or scissors, the edges will adhere with -considerable tenacity. This may be increased by applying some thick -solution of india rubber in a volatile solvent, and by manipulating the -sheets so as to bring the entire surfaces of the cuts together. Finally -the material may be charged with sulphur by absorption or by Parkes’ -process, and cured in a glycerine or calcium chloride bath, all of -which are described in chapter XI. The same treatment will affect the -cement used in making the joint also, bringing about its vulcanization. - -Such in a few words is the main process in the treatment of this class -of goods. Where it is desired to prevent adherence, soapy water or -powdered talc is used. - -Adherence may be produced between the surfaces of the sheets if they -are clean, by pressure and a little warmth. The method of making toy -balloons will give an example of how the article is dealt with by the -manufacturer. - -A pile of pieces of masticated sheet rubber is made. Every piece -has one side coated with powdered talc, and two talc-coated sides -are placed in contact in each pair. As they are piled up, the outer -surfaces of each pair are moistened with water. A steel punch or die, -pear shaped in outline, is used to cut down through the pile, cutting -all the pieces into that shape. - -The pile is then taken apart in pairs. The separation takes place -between the wet surfaces, the edges of each pair adhering slightly -so as to enclose the talc-coated surfaces. The neck is opened if -necessary. A rather weak or thin solution of india rubber in benzole -is now brushed over the freshly cut edges. By pulling out the centre -of each piece the edges are brought into contact, and adherence is -produced. - -If the Parkes process of vulcanizing, chapter XI., is employed they are -cured to the slight extent necessary upon a tray coated with talc. The -balloons are then ready for inflation. - -They are rather delicate articles to make except for immediate use as -the thin material is liable to become over vulcanized. - -In the chemical laboratory sheet rubber can be used for covering the -ends of glass stirring rods. These answer very nicely for cleaning out -from beakers the last particles of a precipitate. The sheet is cut of -proper size and is bent around the end of the rod and cut off close -with a pair of scissors. It adheres where cut. It is then pinched with -the fingers to bring the edges into better contact and the operation is -complete. A slight heat makes it adhere better. - -To connect glass tubes in setting up laboratory apparatus the same -material was formerly used. It was wrapped around the joint, tied with -thread and slightly warmed. At present this form of connection is -wholly displaced by ready made rubber tubing. - -It is interesting to observe in all articles made from this sheet the -marks of the original cutting knife. These may be observed in inflated -balloons, as parallel lines running all over the surface, and magnified -by the expansion due to the inflation. - - - - -CHAPTER XI. - -VARIOUS VULCANIZING AND CURING METHODS. - - -The regular methods of vulcanizing and curing can be departed from and -good results obtained. A few excellent methods differing essentially -from the ordinary ones are described which will be of service to -workers on the small scale, as they enable one to dispense with -vulcanizer and air bath entirely. - -One type of curing process does away with the air or steam vulcanizer, -and substitutes, as the curing agency, a hot bath of liquid. For -this purpose a fluid is required that will not act injuriously upon -the india rubber, and which will give a curing temperature without -boiling away. One favorite liquid is glycerine. This can be heated -to the necessary degree and is an excellent substitute for the -expensive apparatus often used. For experimental work it is exceedingly -convenient. - -In use it is placed in a vessel of proper size and a thermometer is -suspended so that its bulb dips into the liquid near one side and -does not touch the bottom of the vessel. The heat is applied by a gas -burner, alcohol lamp or oil stove. Of course the vessel may be placed -on an ordinary cooking stove or range, and the heat may be graduated -and adjusted by moving it about until it reaches a part of the stove -where the proper heat will be maintained. - -The mould with its contents is immersed in the glycerine, care being -taken to see that it so placed as to assume the mean temperature of -the liquid and not to be heated too hot. This might happen if it stood -on the bottom of the vessel, so it is well to have it supported or -suspended a little above it. - -It is easy to see that the whole may be so arranged that the screw -handle or pressure nuts of the mould will rise above the liquid. In -this case the press can be screwed down while the article is heating. - -Instead of glycerine a strong solution of some salt in water has been -recommended. A solution of calcium chloride, or some other salt can be -substituted. Either are very cheap and will be quite satisfactory. - -Another treatment which applies also to the mixing operation is by the -sulphur bath. Sulphur is melted in an iron vessel and brought to a -temperature of 248° F. (120° C.). A piece of unmixed pure caoutchouc -immersed in this bath will gradually absorb sulphur. The case is almost -parallel with the absorption of water or benzole by the gum. The piece -swells and thickens as it is acted on and eventually will contain -enough sulphur for vulcanization. It may absorb as much as fifty per -cent. The point of proper absorption must be settled more or less -empirically or by successive trials. - -After enough has been taken up the piece is removed and dipped into -cold water, which cracks the adherent sulphur so that it can be brushed -or rubbed off. This gives a piece of mixed rubber ready for moulding -and curing. It can be heated and moulded and may be cured as desired, -in a liquid bath, hot press or vulcanizer. - -It will be observed that this provides for the admixture of sulphur -only; no talc or other solid can be thus introduced. The addition of -these solids tends to make the rubber of a more attractive color and -their use is not to be deprecated in all cases. Hence the sulphur bath -process is not to be considered a perfect one. - -In the sulphur bath the mixing and curing processes can be combined. -If the liquid sulphur is heated to the vulcanizing temperature, 284° -F. (140° C.), a thin strip of gum immersed in it will be vulcanized -completely in a few minutes. A heating of several hours at the lower -temperature will effect the same result. - -The sulphur bath processes must be regarded as unsatisfactory. It is -not easy to feel that any dependence can be placed upon them as regards -reliability or constancy of product. The sulphur also will mostly -effect the surface. Thin pieces may be satisfactorily treated, but the -same confidence cannot be felt as is experienced when specific amounts -of ingredients have been mixed in with pure caoutchouc in a regular -mixing machine. - -The sulphur bath is of value to the experimenter, enabling him to do -his own mixing without expensive apparatus. - -Bromine, iodine, chlorine and nitric acid are vulcanizers. A piece of -sheet rubber dipped into liquid bromine is instantly vulcanized. Iodine -and nitric acid have also been used in commercial work. - -Alkaline or alkaline earth sulphides can be employed in solution under -pressure for vulcanizing. At a vulcanizing temperature their solutions -will answer for thin sheet very well. Polysulphides of calcium have -thus been employed. - -By simply lying embedded in finely divided sulphur at a temperature of -233° F. (112° C.) as much as ten per cent. of sulphur may be absorbed -by thin sheet rubber. This is one of the processes peculiarly suited -for work on the small scale. It may be used instead of the Parkes -process next to be described. - -Chloride of sulphur is an orange red mobile liquid of a peculiar and -disagreeable odor. It boils at 276° F. (136° C.). It dissolves both -sulphur and chlorine so that it is not easy to obtain it in a pure -state. If unmixed india rubber is exposed to its action it will quickly -become vulcanized. At ordinary temperatures the mixing action takes -place, though it is much accelerated by a slight application of heat. - -It is quite possible that this action may be of use to the reader -in his manipulation of india rubber. Thin sheet may be vulcanized -by being immersed in a solution of this substance in bisulphide of -carbon followed by slight heating. The thin layer of caoutchouc left -by evaporation of the chloroform solution of india rubber may thus be -vulcanized so as to become comparatively strong and elastic. Where the -same solution has been used as a cement or for patching overshoes and -finishing the patch, a vulcanization can thus be given to it. - -The process is known as Parkes’ cold curing process. - -A solution of one part of chloride of sulphur in forty parts of -bisulphide of carbon is of good strength for rapid work. A thin article -needs but an instant of immersion. It then is placed in a box or tray -upon some talc powder and is heated to about 104° F., (40° C.). One -minute of curing will suffice. It is advisable to wash off the articles -afterwards in water or in weak lye to remove any traces of acid. - -Petroleum naptha can be used as the solvent instead of bisulphide of -carbon. The latter substance has an exceedingly disagreeable odor, and -its vapors must be considered rather injurious especially to those who -are not accustomed to them. - -When thick articles are to be cured by this process a much more -diluted solution is used. One per cent. or less of the chloride of -sulphur is the proportion used. The object of this is to enable a -longer immersion to be employed so that the interior will be affected -before the outer layers become too much charged with the vulcanizing -material. - -In this short description of the Parkes curing process hints for a -useful method may be found. The process is beyond doubt by far the -simplest known for treatment of india rubber. Exactly what reaction -takes place is unknown. Whether the sulphur or the chlorine is the -acting vulcanizer has not as yet been determined. - -Its defect is that it produces surface action, analogous to -casehardening. One method of avoiding this is to remove the articles -from the sulphur chloride bath and at once to immerse them in water. -This prevents the rapid volatilization of the solvent and an equalizing -of the absorption ensues. - - - - -CHAPTER XII. - -THE SOLUTION OF INDIA RUBBER. - - -India rubber presents some difficulties in its solution. If a piece -of pure gum just as received by the factory is placed in hot water -it will swell and whiten after a while, but will not dissolve. If a -similar piece is placed in benzole a similar but greatly exaggerated -action takes place. The piece if left to soak for a day or more swells -enormously, but very little solution is effected. - -The swollen india rubber can be removed from the benzole in a single -piece. It will display all the layers and marks of the original piece -which was perhaps of not one hundredth part of its volume. Some parts -will be a perfect transparent jelly. - -It has been found that masticated india rubber dissolves with -comparatively little difficulty. If the experimenter will place in a -porcelain mortar, the jelly-like mass obtained as above detailed, and -will rub it up thoroughly, it will be effectually masticated. This -requires a little patience, as the slippery material seems to elude -the pestle. Yet eventually it will all be reduced to a perfectly -homogeneous mass. Its action while being rubbed up is very peculiar. -At first no progress seems to be made. After a little the lumps yield -to the friction. The rubber then begins to attach itself to the pestle -and mortar, and begins to be drawn out into ever changing webs and -threads. As the operation approaches completion the material makes a -snapping, crackling noise familiar to all rubber workers. When complete -there will be no lump left, and the whole will be a uniform pulp. - -If benzole or a volatile solvent has been used, the rubber will -easily be removed from the mortar with a spatula or palette knife. If -turpentine was the solvent it will be impossible to remove the last -traces except after long standing or by solution. - -If replaced in the original solvent it will now come into nearly or -quite perfect solution. This is the best way of masticating on the -small scale. It is almost impossible to masticate untreated gum in an -ordinary mortar. - -The dealers sell a special india rubber for the manufacture of cement -and solutions. This is so treated by mastication that it dissolves with -great readiness. It is also said that heating under pressure is used to -dissolve it in some factories. - -Many solvents have been used and none work without some difficulty. -Benzole, coal tar naptha, petroleum naptha, carbon disulphide, ether -and chloroform, oil of turpentine and caoutchoucin are the best known. -The naptha best suited for its solution is termed solvent naptha. It -has a specific gravity of .850 at 60° F. (15½° C.); it boils at from -240° F. (115½° C.) to 250° F. (121° C.) and on evaporation should leave -no more than ten per cent. of residue at 320° F. (160° C.) - -Payen recommends a mixture of 95 parts bisulphide of carbon with 5 -parts of absolute alcohol. - -Commercial chloroform is apt to be too impure to act as a good solvent. -It is apt to contain alcohol mixed with it as a preservative, which -impairs its effectiveness. - -Some of these solutions are better suited than others for the -deposition of thin layers by evaporation. Turpentine gives a very -sticky and unmanageable solution, which dries very slowly. Payen’s -solution and the chloroform and the benzole solutions may be cited as -especially adapted for this purpose. Careful vulcanization by the cold -curing method can be applied to articles made by such deposition from -evaporation. - -In the case of all of them some form of mastication for the india -rubber is needed. The simple mortar grinding of the gum swelled by the -solvent is the only practical treatment without special apparatus. - -When it is remembered that fixed oils are destroyers of vulcanized or -unvulcanized india rubber it will be obvious how important it is to use -pure solvents. Too great care cannot be taken to preserve the liquids -pure and free from such matter. - -A solid hydrocarbon may be used. Thus paraffin wax, such as candles -are made of, when melted acts as a solvent. The resulting liquid -solidifies when it cools, retaining an almost greasy feel. - -Boiling oil of turpentine is recommended by some for the solution of -vulcanized india rubber. Phenyle sulphide, it is stated, will soften it -so as to render it workable. The latter discovery is credited to Dr. -Stenhouse. - -It is stated that a solution or pasty mixture of one part of caoutchouc -in eleven parts of turpentine with one half part of a hot concentrated -solution of sulphur (potassium sulphide) gives on evaporation a film -neither tacky nor soft, a species of vulcanization taking place. - -It is of much interest to note that an aqueous solution of india rubber -has been proposed in which the vehicle is a solution of borax in water. -This is well known to be a solvent for shellac and other resins. It -has been recommended often as a vehicle for rubbing up india ink. -The ink made by mixing lampblack with the shellac solution is nearly -waterproof. A shellac varnish is given by the plain solution. - -The experiments upon india rubber were published in a recent trade -paper. One method of making the solution is as follows. - -A solution of borax two fifths saturated is made by adding to two -volumes of saturated solution three volumes of water. To this is added -a solution of india rubber in benzole or other hydrocarbon of such -strength and in such quantity as to contain from three and one-half -to four and one-half per cent. of india rubber referred to the borax -solution. It is now vigorously shaken and heated to 120°-140° F. -(49°-60° C.) and the agitation, not too violent, is continued until it -cools. Ceara or Madagascar rubber answers best; Para is not so good for -this formula. This may be termed the indirect or emulsion method. - -For direct solution from two to three volumes of water may be added to -three volumes of saturated borax solution. The india rubber is added in -extremely thin shavings and the solution is heated. For weak solutions -the boiling point need not be reached. For strong solutions the heating -should be done under pressure so as to bring up the pressure to one to -three atmospheres. - -Such solutions may contain as much as eight per cent. of the gum. The -mixture is liable to coagulate or gelatinize just at the wrong time, -but it may be of value as a vehicle or as a waterproofing agent. It -deserves further investigation, which it is to be hoped it will duly -receive. - -Great care is necessary in working with naptha, benzole, carbon -disulphide and similar liquids. Their vapor is given off at ordinary -temperatures and may travel some distance to a lamp or fire and become -ignited and carry the flame back to the vessel. Their vapors are also -anæsthetic and should be avoided as regards inhalation. - - - - -CHAPTER XIII. - -EBONITE, VULCANITE AND GUTTA-PERCHA. - - -_Ebonite and Vulcanite._--These two well known substances are india -rubber, in which the vulcanization process has been intensified. From -twenty-five to fifty per cent. of sulphur is added in the mixing, and -the curing is prolonged to several hours. A temperature of 275° F. -(135° C.) for six to ten hours is sometimes recommended, but generally -a shorter period at the regular temperature, 284° F. (140° C.), may be -employed. - -The mixed sheet is made and sold extensively for dentists’ use. It -is soft and flexible and very easily moulded. It is treated like the -regular mixed sheet in every respect, except that plumbago brushed on -the slightly oiled surface of the mould is recommended instead of the -light colored talc, to prevent adherence. Wax where available is better -than oil. - -Sometimes specimens are built up in sections. About an hour before full -vulcanization in the fourth stage, new material can be added and will -attach itself to the old. The stages of vulcanization are thus given by -Bolas. - -“Several distinct stages or steps may be traced during the curing -of ebonite; and I wish to call your attention to some specimens -illustrating these various stages. - -“Here, in the first place, is the plain mixture of sulphur and rubber, -this being nearly white, and capable of becoming quite plastic or soft -by the application of a gentle heat. - -“The second specimen illustrates the action of a very moderate degree -of heat on the mixed material, this particular sample having been -heated to 128° Centigrade for twenty minutes. It is, as you see, -somewhat darkened, and has lost a little of its original softness; -while a degree of heat which would have rendered the original mixture -plastic, like putty, fails to make much impression upon it. - -“The third specimen illustrates the effect of a more prolonged heating, -this sample having been heated for an hour to 135° Centigrade. It is -olive green in color, and has acquired a certain amount of elasticity, -resembling that of a rather inferior quality of vulcanized caoutchouc. - -“The fourth stage of curing is illustrated by this specimen, which -you see is brown, and tolerably hard. Ebonite in this state refuses -altogether to become plastic by heat, and a temperature of 150° -maintained for half an hour or less would suffice to bring it to the -fifth stage, or that of finished ebonite. - -“The fifth stage, or that of properly cured ebonite, is the goal -to be arrived at in manufacturing the material. There should be no -places where the curing is imperfect, a kind of defect which is likely -to happen when articles of unusual thickness are vulcanized, and no -portion of the ebonite should be spongy or honeycombed by air bubbles. - -“The sixth, or spongy state, is generally the result of over-heating, -bubbles of gas forming in the material, and converting it into a kind -of porous, cinder-like mass. - -“A specimen will now be handed round, which illustrates the third, -fourth, fifth and sixth stages, as already described. The specimen in -question was cured on a hot plate, this having probably been heated to -160° or 170° Centigrade; and you will be able to trace all gradations -in the curing operation, from the first setting of the plastic material -to the destruction of the ebonite by overheating.” - -Cement for uniting pieces of the partially cured material may be made -by rubbing up some of the untreated scrap with benzole. - -At the heat of boiling water, ebonite can be bent to a certain extent, -which bend it retains on cooling. When warm an impression of a coin or -relief die may be made on it by heavy pressure which it will retain. On -heating the image disappears. If before heating the surface is planed -off and the piece is heated the image formerly in intaglio will expand -into relief. - -By the exact process of rubber stamp making excellent stereotype -plates may be made of ebonite. - -It can be turned at high speed in a lathe and polished with fine 000 -emery paper followed by a cloth bob with rotten stone, etc., and water -or oil. Blotting paper, charged with the above or with tripoli, is -excellent for polishing small surfaces by hand. - -Ebonite is a good connecting material between softer rubber and iron, -the whole being vulcanized together; the iron should be well roughened -or cut into rasp-like or file-like projections. - -Ebonite is properly the name for black hard rubber, and vulcanite for -the colored products such as used by dentists and others. - - -GUTTA-PERCHA. - -Gutta-percha is prepared by coagulation from the juice or sap of -several trees, among others the _Isonandra gutta_, of Borneo and the -East Indian Archipelago. The product gutta-percha is identical in -composition with india rubber. It is hard at all ordinary temperatures. - -Its manufacture includes purification and mastication. It is far more -amenable to treatment than is india rubber. Many materials are mixed -with it as adulterants or otherwise in the factories. - -It is more useful in the form of sheets. These when heated to 122° F. -(50° C.) become pliable and can be moulded by pressure to any degree. -At the temperature of boiling water it becomes pasty and adhesive, and -at 266° F. (130° C.) it is so soft that it may be considered as melted. - -It is an admirable moulding material. Stereotypes and other relief or -intaglio images can be made by pressing it while heated. These are -often absolutely perfect reproductions of the original. - -Dishes for photographic purposes, etc., are easily made out of the -sheet. By gentle warming they become pliable, and a greater heat makes -surfaces capable of adhering by pressure. - -Tubes can be made by the squirting process, as used for india rubber. -Wires are coated with it in a similar manner. - -It has several defects. It is not durable if exposed to the air with -consequent changes of temperature. It is also too easily softened by -heat, as of course no hot liquid can be introduced into a gutta-percha -vessel. The Parkes cold curing process can be applied to it, which -makes it more indifferent to heat. This is applied by dipping an -instant and drying. After several repetitions the period of dipping -is prolonged and ultimately it is left immersed some time. If left -immersed at first it would dissolve. - -It is soluble in most caoutchouc solvents, particularly in carbon -disulphide. - - - - -CHAPTER XIV. - -GLUE OR COMPOSITION STAMPS. - - -Stamps made from a mixture of glue, glycerine, and molasses or from -similar mixtures are an excellent substitute for india rubber stamps. -Properly made they possess all the flexibility that characterizes the -rubber ones, while for fatty inks such as that used by printers and -lithographers, which inks tend to destroy rubber stamps, they are much -better. They are adopted by the United States government for making -dating stamps for use in the Post Office Department; by publishers -of directories for printing advertisements on the edges of their -publications, and in many other cases. Our description shall follow as -closely as possible the process and methods used in the United States -Post Office. They are there termed “composition blotters.” - -The composition of which they are made is printer’s roller material. -Nine and one-half pounds of fine quality glue are soaked in just enough -soft water to cover it until it is thoroughly softened. It is then -melted. In the Government Department a steam kettle is provided for -the purpose. An ordinary glue pot will answer for smaller quantities. -When melted four and one-half pounds of best molasses and seven pounds -of glycerine are added, and the whole is thoroughly mixed. The formula -varies a little according to the prevailing temperature, less molasses -being added when the weather is warm, and _vice versa_. Experience is -here the best teacher. When well mixed it is poured out into tin pails -whose inner walls or sides and bottom have been rubbed over with oil. -It solidifies in cooling and becomes a clear brown jelly quite free -from any stickiness or superficial moistness. - -[Illustration: MODEL FOR COMPOSITION STAMP MOULD.] - -In use it is turned out of the pails to which, owing to the oiling, it -does not adhere. It is cut off as wanted, melted by heat and cast in -oiled moulds. - -The latter are made of type metal to which one-third its weight of lead -has been added. As model for the mould or matrix a brass model of the -stamp is employed. This represents a sort of oval based cut-off or -truncated cone, about an inch high and a little over an inch long on -its base. A flange extends outward from its base and a tube is provided -to fit this flange. Its smaller end corresponds to the face of the -stamp, and on it are engraved in full relief any permanent characters, -circles or border lines, etc. Through its centre one or more apertures -are made. Into these, changeable steel, iron or brass type may be -introduced and set fast with plaster of paris. - -[Illustration: COMPOSITION STAMP MOULD.] - -To make the mould, the brass model with its movable type set as -required is placed upon a flat table or plate, face upward, and -surrounded by the tube, as shown in partial section in the cut, page -114. The tube is a strip of sheet iron, which is bent around the flange -and is secured in place by a wire twisted around it. The melted alloy -(type, metal and lead) is poured into the space thus formed until -it rises a quarter of an inch above the face of the model. In a few -minutes it sets and is removed and allowed to cool. This gives a cup -with the inscription and design depressed or in _intaglio_ upon its -inside base. This is shown in the cut, page 115, partly in section; it -will of course be understood that the mould forms a complete cup. - -To make the stamp the interior surface of the mould is oiled with a -stiff brush. It is not material what oil is used. The composition -melted by heat is then poured into the cup, and is allowed to solidify. -Owing to the conical shape of the mould it is readily removed. The -mould must be hot but not too much so. - -In the Post Office stamps the date requires to be changed frequently. -Some of the figures do duty for two or three days each month. Thus the -figure 8 is in the designation of three days, the eighth, eighteenth, -and twenty-eighth. There are three changes involved therefore in -connection with this day numeral. When a stamp mould or matrix is -cast the place of numerals that are to be changed is filled with a -blank space in the part where the type would otherwise come. A number -is stamped in this space when needed, by means of an ordinary steel -number-punch. - -When the number is to be changed the old character is scraped or cut -out, leaving a small irregular hollow. A very small piece of soft -lead, about one-sixteenth of an inch on each side, is dropped into -the hollow. With a flat faced punch it is flattened out, and on it the -new number is impressed by a steel punch. This operation is repeated a -great many times before the matrix is worn out. - -[Illustration: - - OPEN SHUT - -COMPOSITION STAMP HANDLE.] - -In the cut, page 115, one number is shown as stamped into the soft -lead, and at the other end of the stamp is a blank space ready for a -number. - -The casting of a stamp is so extremely simple that no attempt is made -to use movable type, as in permanent rubber dating stamps. - -While it is obvious that these composition stamps could be attached -directly to wooden handles, a special style of handle, shown in the -cuts, is employed by the Post Office. A wooden handle carries at -its end a brass base, to which is pivotted a swinging piece that is -perforated by a conical oval aperture a little larger than the small -end of the stamp. The edges of this aperture are slightly rounded. - -It is swung around as shown in the first figure, and the stamp, -previously moistened on its sides, is forced in. If the stamp is -properly made it is surprising how much force may be used to insert -it. If the edges of the brass swinging piece are not rounded there is -danger of the composition being cut. The stamp in its brass frame is -then swung back over the brass base, where it is secured by a catch. -The stamp is now ready for use, as shown in the second figure of the -cut. - -It is imperative that no aqueous or glycerine ink be employed for -continuous work with such stamps. Common printers’ ink is perfectly -satisfactory, and the work may be nearly or quite as good as that -executed by an india rubber stamp. - -The Post Office manufactures a pad for use with printers’ ink into -whose manufacture the same composition enters. The ink retainer is a -piece of fine felt, one-quarter to one-half an inch thick. This is -placed in the bottom of a shallow steel mould, where it enters for half -its depth into a recess that it accurately fits. The composition from -old stamps, melted up, is then poured upon and around it, the mould -being previously oiled. When it is full a piece of strong manilla -paper, of the area of the felt only, is placed upon the bottom of the -glue pad on its centre, which as it lies in the mould is its uppermost -part. The paper adheres strongly as the glue hardens. Eventually it -is turned out of the mould, and a pad, shown in the cut, is produced. -The dotted lines show the limits of the felt pad. The glue composition -underlies, surrounds and extends outwards from the felt portion. It -is found that the elasticity of the composition makes the pad much -pleasanter for rapid stamping. - -[Illustration: COMPOSITION INK PAD.] - -The above description gives the clew to making any stamp of this -description. The matrix may be of dental plaster, or of oxychloride of -zinc cement. The mould may be built up of type of any kind. - -The composition is so cheap that the stamp can be made quite thick. -This gives it a high degree of elasticity and adaptability to uneven -surfaces. It may be mounted by adherence upon a flat board or block, -provided, if necessary, with handles. If the board or block is -placed upon the composition while it is still warm and liquid, as it -solidifies the board and composition will adhere with great tenacity. - -All moulds or surfaces to which it is desired that the melted -composition shall not adhere must be oiled. - -The moulds must not be cold or the composition will not enter the fine -divisions. If on the other hand they are too hot the mixture will -adhere. Experience will teach the right conditions for success. - -Below are given other formulæ for roller composition. The formula -already given in this chapter is that used by the United States Post -Office Department. - -I. “Old Home Receipt:” Glue 2 lbs., soaked over night, to New Orleans -molasses 1 gallon. Not durable, but excellent while it lasts. - -II. Glue 10½ lbs., molasses 2½ gal., Venice turpentine 2 oz., glycerine -12 oz.; mix as directed above. - - - - -CHAPTER XV. - -THE HEKTOGRAPH. - - -For obtaining multiple copies of writing, the apparatus called the -Hektograph or Papyrograph has been extensively adopted. In general -terms it consists of a tray filled with a jelly like composition. Any -imprint made upon the surface with aniline ink can be transferred to -paper by simple pressure. The tray filled with composition is called -the tablet. It is thus prepared. - -The tray may be made of tin or even of pasteboard or paper, and should -be about one half an inch deep. It may be of any size, according to the -work it is to do. The composition is made from the best gelatine and -glycerine. One ounce by weight of gelatine is soaked over night in cold -water, and in the morning the water is poured off, leaving the swelled -gelatine. Six and one-half fluid ounces of glycerine are now heated -to about 200 F. (93 C.) on a water bath preferably, and the gelatine -is added thereto. The heating is continued for several hours. This -operates to expel the water and to give a clear glycerine solution of -gelatine. - -The composition is then poured into the tray, which must be perfectly -level in order to obtain a surface nearly even with the edge. It is -then covered so as to keep off the dust. The cover of course must not -come in contact with the smooth surface. In six hours it will be ready -for use. - -The original copy that is to be reproduced is made upon ordinary paper -in aniline ink. One formula for the ink reads as follows: Aniline -violet or blue (2 R B or 3 B) 1 oz., hot water 7 fluid oz.; dissolve. -After cooling add alcohol 1 fluid oz. and glycerine ¼ fluid oz., a few -drops of ether and a drop of carbolic acid. Keep in a corked bottle. -Other formulæ are given in chapter XVII. - -The writing is executed with an ordinary steel pen. The lines should be -rather heavy so as to show a greenish color by reflected light. - -The surface of the pad is slightly moistened with a wet sponge and -is allowed to become nearly dry. The paper is then laid upon it and -smoothed down. This is best done by placing a second sheet over it and -rubbing this with the hand. No air bubbles must remain between the copy -and the tablet, and the paper must not be shifted. - -It is allowed to remain for a minute or less and is then raised by one -corner and stripped from the gelatine surface. It will have left the -reversed copy of its inscription perfectly reproduced upon the tablet. - -At once a piece of ordinary writing paper of the desired size and -quality is laid upon the tablet, smoothed down, and stripped off, -when it will be found to have taken with it a complete copy of the -inscription or writing. This is repeated over and over again with -another sheet of paper, until the ink on the pad is exhausted. Fifty or -more good copies can be thus obtained. - -[Illustration: THE HEKTOGRAPH.] - -As soon as the work is completed the remains of the ink should be -washed off with a moist sponge and the tablet, after drying a little, -will be ready for a second operation. - -Some practice is required to ascertain the proper strength of the -writing and degree of wetness of the surface. When the gelatine surface -becomes impaired it can be remelted in a water bath if it is not too -dark from absorption of ink. - -_French Ministry of Public Work Formula._--Glue 100 parts, glycerine -500 parts, finally powdered kaolin or barium sulphate 25 parts, water -375 parts. Use a little hydrochloric acid in the water for washing off -the pad after use. - -_Hektograph Sheets._--Four parts of glue are soaked in five parts of -water and three parts of ammonia until soft. It is then heated and -there is added to it three parts of sugar and eight parts of glycerine. -The mixture is applied to blotting paper. This is saturated with it, -and successive coats added until a smooth surface is produced on one -side. This is the side for reproduction. It is used like the regular -tablet except that it is claimed that sponging off the writing is not -necessary. Owing to the capillary action developed by the blotting -paper it is supposed to be self-cleaning by standing. - - - - -CHAPTER XVI. - -CEMENTS. - - -Before cementing vulcanized rubber the surface should be roughened or -still better it may be seared with a red hot iron. For bicycle tyres -this is especially to be recommended. - -_Cement for Cuts in Bicycle Tyres, Rubber Belts, etc._--Carbon -bisulphide, 5 ounces; gutta-percha, 5 ounces; caoutchouc, 10 ounces; -fish glue, 2½ ounces. After it is applied and has dried the excess can -be removed with a wet knife. Bad cuts should first be stitched up. - -_Bicycle Tyre Cement to fasten Tyres to Rims._--Equal parts of pitch -and gutta-percha are melted together. Sometimes two parts of pitch are -prescribed. This cement has extended application. - -_Cement for Paper Boats and for Mending Rubber Goods._--Fuse together -equal parts of pitch and gutta-percha, and to this add about 2 parts of -linseed oil containing 5 parts of litharge. Continue the heat until the -ingredients are uniformly commingled. Apply warm. - -_Waterproof Cement._--Shellac, 4 oz; borax, 1 oz; boil in a little -water until dissolved, and concentrate by heat to a paste. - -_Another._--10 parts of carbon disulphide and one part of oil of -turpentine are mixed, and as much gutta-percha is added as will readily -dissolve. - -_Cement for Mending Hard Rubber._--Fuse together equal parts of -gutta-percha and genuine asphaltum; apply hot to the joint, closing the -latter immediately with pressure. - -_Glue to Fasten Leather, etc., to Metals._--1 part crushed nut galls -digested 6 hours with 8 parts distilled water and strained. Glue is -macerated in its own weight of water for 24 hours, and then dissolved. -The warm infusion of nutgalls is spread on the leather; the glue -solution upon the roughened surface of the warm metal; the moist -leather is then pressed upon it and dried. - -_Marine Glue, Various Formulæ._--I. Dissolve 1 part of india rubber -in 12 parts of benzole, and to the solution add 20 parts of powdered -shellac, heating the mixture cautiously over a fire. There is great -danger of conflagration. Apply with a brush. - -II. Caoutchouc, 1 oz; genuine asphaltum, 2 oz; benzole or naptha, q. s. -The caoutchouc is first dissolved (as described in chapter XII.), and -the asphaltum is gradually added. The solution should have about the -consistency of molasses. - -_Cement for Vulcanized India Rubber._--Stockholm pitch, 3 parts; -American resin, 3 parts; unmixed india rubber, 6 parts; oil of -turpentine, 12 parts. Heat and mix very thoroughly. More oil of -turpentine may be added as required. - -_Gutta-Percha Cement for Leather._--Soak gutta-percha in boiling water. -Soften in benzole after cutting up for a day. Heat on a water bath -until the greater part of the benzole is expelled. When cool it will -solidify. Use by heating. - -_Cement for Rubber Shoes._-- - - (1) Chloroform 280 parts. - India rubber (masticated) 10 ” - (2) India rubber 10 ” - Resin 4 ” - Venice turpentine 2 ” - Oil of turpentine 40 ” - -For first solution dissolve by mastication. For second, melt the finely -divided gum with the resin, add the Venice turpentine and finally the -oil of turpentine. Use heat if necessary. Mix both solutions finally. -To apply, saturate a piece of linen with the cement and apply to the -spot previously coated with the cement. As it dries apply a little more -as required. A finishing varnish is given in the last chapter. Parkes’ -cold curing process may be applied as described in chapter XI. - -_Chatterton’s Compound_ for uniting sheets of gutta-percha in cable -cores and for general work with gutta-percha coated wires.--Stockholm -tar, 1 part; resin, 1 part; gutta-percha, 2 parts. - -_Waterproofing for Wooden Battery Cells._--Resin, 4 parts; -gutta-percha, 1 part; boiled oil, a little. - -_Another Formula._--Burgundy pitch, 150 parts; old gutta-percha in fine -shreds, 25 parts; ground pumice stone, 75 parts. Melt the gutta-percha -and mix with the pumice stone and then add the pitch, melting all -together. Apply melted and smooth off with a hot iron. - -_Cement for Celluloid._--Shellac, 1 part is dissolved in spirits of -camphor 1 part, with 3 to 4 parts strong alcohol. It is applied warm -and the parts united must not be disturbed until the cement is hard. - - - - -CHAPTER XVII. - -INKS. - - -RUBBER STAMP INK. - - Aniline blue soluble, 1 B 3 parts. - Distilled water 10 ” - Acetic acid 10 ” - Alcohol 10 ” - Glycerine 70 ” - -For other colors the following aniline colors may be substituted in -proportions given: - - Methyl violet, 3 B (violet) 3 parts. - Diamond fuchsin I, (red) 2 ” - Methyl green yellowish 4 ” - Vesuvin, B (brown) 5 ” - Nigrosin, W (blue black) 4 ” - -For very bright red 3 parts of Eosin BBN. are used. In this case the -acetic acid must be omitted. In all cases the colors should first be -rubbed up with the water in a mortar, and the glycerine should be added -gradually. These inks will answer for the hektograph. - -_Hektograph Ink._--Aniline color, 1 part; water, 7 parts; glycerine, -1 part. A little alcohol may be used with advantage to dissolve the -aniline color. It can be expelled by heating if it proves objectionable. - -_Aniline Ink Vehicle._--Prof. E. B. Shuttleworth, of Toronto, Ont., -suggests the use of castor oil in place of vaseline and other vehicles -for typewriter ink. The aniline colors may first be dissolved in -alcohol, and the solution may be added to the oil. They may also be -dissolved directly in the oil in which most of them are soluble. - -_Indelible Stamping Inks._--I. Asphaltum, 1 part; oil of turpentine, 4 -parts; dissolve and temper with printer’s ink. The ink may be omitted, -and solid dry color added. - -II. Sodium carbonate, 22 parts; glycerine, 85 parts; dissolve and rub -up in a mortar with gum arabic, 20 parts. In a separate vessel dissolve -silver nitrate, 11 parts; in officinal aqua ammonia, 20 parts. Mix the -two solutions, and heat to the boiling point, 212° F. (100° C.). After -it darkens, add Venice turpentine, 10 parts. After applying to the -cloth, a hot iron should be applied, or it should be exposed to the sun. - -III. Dr. W. Reissig’s formula: - - Boiled linseed oil varnish 16 parts. - Finest lamp black 6 ” - Ferric chloride (sesquichloride of iron) 2 to 5 ” - -Dilute a little for use with varnish. After this ink has been removed, -no matter how completely it can be detected by dipping the paper into -a solution of ammonium sulphide. - -IV. - - Aniline black in crystals 1 part. - Alcohol 30 ” - Glycerine 30 ” - -Dissolve in the alcohol, and add the glycerine afterwards. - -_Show Card Ink._-- - - Pure asphaltum 16 parts. - Venice turpentine 18 ” - Lamp-black 4 ” - Oil of turpentine 64 ” - -Dissolve the asphaltum in the turpentine, and thoroughly mix. - -_Stencil Ink._--Shellac, 2 ounces; borax, 2 ounces; water, 25 ounces. -Dissolve by heat if necessary, first the borax alone, and then adding -the shellac. To the clear solution add gum arabic, 2 ounces. Color with -lamp-black, with Venetian red, or with ultramarine, to suit the taste. -Another formula gives shellac, 4 parts, borax, 1 part, and omits the -gum arabic. - -_Copying Ink_ (for use without a press by simply pressing and rubbing -with the hand), by Prof. Attfield, F.R.S.--Use ink of any kind of extra -strength. This in many cases can be made by evaporating common ink -down to six tenths of its volume. Then mix with it two thirds of its -volume of glycerine, so as to restore the original volume. - -_White Ink._--Barium sulphate, or “flake white” is mixed with gum -arabic water of sufficient thickness to keep it suspended, at least -while in use. Starch or magnesium carbonate or other white powder -may be used instead of the barium sulphate. The powder must be of -impalpable fineness. - -_White Ink on Blue Paper._--A solution of oxalic acid in water is -used for this purpose. It may be applied with a rubber stamp or with -a common pen. A quill or gold pen is the best as a steel pen is soon -corroded. The ink bleaches the paper wherever it touches it, giving -white lines on a blue ground. - -_Gold Ink._--Gold leaf with honey is ground up in a mortar, best an -agate mortar, or on a painters’ slab with a muller. It is added to -water, and thoroughly mixed and at once poured off from the first -sediments, filtered out, and washed. This is done to secure the -impalpably finely ground gold only. The resulting powder is mixed with -a suitable vehicle, such as white varnish or gum arabic water. - -_Silver Ink._--As above, using silver leaf. - -_Zinc Label Ink._--I. Verdigris, 1 part; ammonium chloride, 1 part; -lamp-black, ½ part; water, 10 parts. - -II. Platinum bichloride, 1 part; gum arabic, 1 part; water, 10 parts. - -_Diamond Ink for Etching Glass._--This consists essentially of -hydrofluoric acid mixed with barium sulphate to the consistency of -cream. The barium sulphate is quite inoperative except as giving a body -to prevent the ink from spreading. It is applied with a rubber stamp -or pen and allowed to remain for ten minutes or until dry. On removal -of the white powder, the design will be found etched on the glass. The -following is a formula for it. - -Saturate hydrofluoric acid with ammonia, add an equal volume of -hydrofluoric acid and thicken with barium sulphate in fine powder. - - - - -CHAPTER XVIII. - -MISCELLANEOUS. - - -_To Soften and Restore India Rubber Hose, etc._--I. Dip in petroleum -and hang up for a couple of days. Repeat process if necessary. - -II. The above process is applicable to all articles, but is specified -for hose. It is stated that old rubber that has become hard may be -softened by exposure first to vapor of carbon disulphide, followed by -exposure to the vapor of kerosene. The latter vapor is found to be a -general preservative for india rubber. - -III. Dr. Pol recommends immersion in a solution of water of ammonia, 1 -part, and water 2 parts, from a few minutes to an hour. - -_To Prevent Decay of Rubber Tubing._--The decay of rubber tubing has -been attributed to the formation of sulphuric acid from the sulphur -mixed with it. M. Ballard has suggested washing with water or weak -alkaline solution five or six times in a year. - -_Joints between India Rubber Tubing and Metal._--Where tubing is -temporarily slipped over metal gas pipes and similar connections, as in -the chemical laboratory, it is well to apply glycerine to the metal. -It acts as a lubricant in slipping the tubing on, and assists in its -withdrawal. - -_Preserving Vulcanite._--Wash occasionally with a solution of ammonia -and rub with a rag slightly moistened with kerosene oil. - -_Effect of Copper upon Rubber._--In a paper read before the recent -meeting of the British Association, Sir William Thomson stated that -metallic copper, when heated to the temperature of boiling water, in -contact with the rubber, exerted a destructive effect upon it. With a -view to finding whether this was due to the copper _per se_, or to its -power of conducting heat more rapidly to the rubber, he laid a sheet -of rubber on a plate of glass, and on it placed four clean disks, one -of copper, one of platinum, one of zinc and one of silver. After a -few days in an incubator at 150° F., the rubber under the copper had -become quite hard, that under the platinum had become slightly affected -and hardened at different parts, while the rubber under the silver -and under the zinc was quite hard and elastic. This would warrant -the inference that the metallic copper had exerted a great oxidizing -effect on the rubber, the platinum had exerted a slight effect, while -the zinc and silver respectively had no injurious influence on it. -The rubber thus hardened by the copper contained, strange enough, no -appreciable trace of copper; the copper, therefore, presumably sets up -the oxidizing action in the rubber without itself permeating it. - -_Gas Tight Tubings._--Fletcher has invented a gas tight rubber tubing -in which a layer of tinfoil is interposed between two concentric rubber -tubes, all vulcanized together. - -_Printing Colors upon India Rubber._--It may sometimes be desirable -to have a surface of vulcanized india rubber so prepared that it will -take colors such as are used for calico printing. This end is simply -attained by sprinkling the article with farina before vulcanizing. A -small quantity attaches itself and forms an excellent base for color -printing. - -_Gutta-Percha for Coating Glass._--For focusing glass in photography -and for similar purposes where ground glass or a translucent material -is required, a solution of gutta-percha in chloroform is highly -recommended. This is flowed over or painted on the glass and is allowed -to evaporate afterwards. - -_Burned Rubber._--A very soft pure gum sold for artists’ use is -improperly termed burned rubber. It is used in crayon work for removing -and lightening marks by dabbing it against the paper, cleaning the -rubber from time to time. It is so soft that it picks up and removes -crayon marks without the necessity of friction. Thus the rubbing out -or more properly erasing operation can be localized and crayon tints -can be lightened in tone without impairment or “smutting.” It is a -very elegant accessory to the artists’ paraphernalia. To make it, pure -virgin gum, preferably the best Para, is cut into pieces and soaked -for some hours in benzole. A long soaking is advisable. The pieces -are then removed from the benzole and are ground in a mortar until -perfectly homogeneous. The mass is gathered up with a spatula and -is pressed into little tin boxes. If desired it may be dried upon a -water bath. This is not necessary as, if the box is left open, it will -rapidly season itself. It should be very soft, should tend to adhere -to the fingers, yet should leave them easily, and should strip cleanly -from the box. A very little turpentine makes it more adhesive. It may -even be softened in turpentine alone. This gives a gum that seasons -more slowly and is in some respects preferable to the benzole made -preparation. It is sold at a high price by the dealers, as the demand -for it is limited. - -_Rubber Sponge._--This is also an artist’s rubber. It is also used for -cleaning kid gloves. It is made by incorporating with the masticated -or washed and sheeted gum any material or materials that will give off -vapor in the curing process. Damp sawdust and crystallized alum are -used as giving off vapor of water or steam, or ammonium carbonate as -giving off vapors of ammonia carbonic acid gas and steam. The mixed gum -may be cured in moulds, which it will fill by its expansion. - -_Shellac Varnish for India Rubber._--This is made by soaking powdered -shellac in ten times its weight of strong aqua ammonia (26° B.). At -first no change beyond a coloring of the solution is perceptible. After -many days standing the bottle, which should have a glass stopper, -being tightly closed, the shellac disappears, having entered into -solution. It may be a month before complete solution. This forms an -excellent varnish for india rubber shoes and similar articles. It may -be applied with a rag. It is also a good application for leather in -some cases and doubtless many other uses could be made of it. It would -act well as a vehicle for a dark pigment such as lamp-black. It will -rejuvenate a pair of india rubbers very nicely. The ammonia exercises -also a good influence on the rubber. It has been recommended as a -cement for attaching rubber to metal, but its adhesive powers are not -always satisfactory. - -_Simple Substitute for Stamps._--A very simple though rough and -imperfect substitute may be made by gluing with common carpenter’s glue -pieces of thick string upon a piece of wood, the string being given the -form of the desired letters. Care must be taken to avoid saturating and -stiffening the string with the glue. - -_India Rubber Substitutes._--One of these under the name of vulcanized -oil is thus described by Bolas: - -“Vulcanized oil is, perhaps, of more interest, and many oils, such as -linseed and others resembling it, may be vulcanized by being heated -for some time to 150° Centigrade with twelve to twenty per cent. of -sulphur. The product obtained is soft, and somewhat resembles very -bad india rubber. By increasing the proportion of sulphur very much -indeed, say to four times the weight of the oil, and vulcanizing at a -higher temperature, a hard substance, resembling inferior vulcanite, is -obtained. - -“Soft and hard vulcanized oil have been introduced into commerce at -various times and under many names; but these materials never seem to -have made very much headway.” - -Another method of treating the oil consists in mixing it with a -solution of chloride of sulphur in carbon disulphide or in naptha. On -standing, the volatile solvents escape, leaving a thick mass, which is -the substitute. - -In combinations of aluminum with the fatty acids, forming aluminum -soaps, and of these, aluminum palmitate especially, a substitute for -india rubber has been sought but without success. - -_Metallized Caoutchouc._--Unvulcanized gum is mixed with powdered lead, -zinc, or antimony. The mixed india rubber is then cured as in the -regular process. - - -EMERY WHEELS AND WHETSTONES. - -Bolas thus describes their manufacture: - -“When ordinary vulcanized rubber is heated to 230° Centigrade, (446° -F.) or until it melts, a permanently viscous product is obtained, and -this substance, if mixed with emery and sulphur to a kind of paste, -forms a material out of which the so-called agglomerated emery wheels -or grinders may be formed, the mixed materials being next hardened or -cured by the application of a steam heat. Emery wheels and hones made -on this principle were introduced by Deplanque about twenty-three years -ago. - -“Thirty-five parts of old vulcanized caoutchouc having been placed in a -kind of still, heat is applied to melt it, the operation being assisted -by the gradual addition of about ten parts of heavy coal oil; but this -latter is afterward distilled off. The softened caoutchouc is then -incorporated with 500 parts of emery of the required degree of fineness -and nine parts of sulphur. These materials having been thoroughly -mixed, the hones or wheels are manufactured, and afterward cured or -baked at a heat of 140° Centigrade, (284° F.) during a period of about -eight hours. Grinding wheels, made in the above manner, can be worked -at a speed of 2,000 revolutions per minute, and are extremely useful -for the working of hardened steel or other obdurate materials.” - -_Etching on Metals and Glass._--India rubber stamps can be used for -placing the ground upon knife blades and similar articles which are -to be etched. The parts untouched by the stamp are attacked by the -acid. In the case of glass, diamond ink (page 133) can be put on -with a stamp. The acids for metal etching might be thickened with -barium sulphate also and applied in the same way. In these cases the -inscription of the stamp would be etched. Where ground is put on, -whether on glass or metal, the design for the stamp will be protected. - -_Etching Ground for Metals._--Equal parts of asphalt, Burgundy pitch -and beeswax melted together and mixed thoroughly. It may be softened -with mutton suet. Beeswax may be used, dissolved in ether or simply -melted. Yellow soap is sufficient for ordinary work. - -_Etching Solutions for Biting in._--For steel and iron, _a._ sulphate -of copper and common salt in solution. _b._ sulphate of copper, -sulphate of alumina, and common salt, of each two drachms; acetic acid, -1½ oz. _c._ sulphuric acid, diluted with five volumes of water with a -little sulphate of copper. For other metals, except gold and platinum, -nitric acid diluted with five volumes of water. - -_Etching Ground for Glass._--Melted beeswax is generally recommended. -It can be removed with spirits of turpentine after as much as possible -has been scraped off. - -_Etching Glass._--Glass may be conveniently etched by exposing it to -the vapor of hydrofluoric acid. A shallow leaden tray, as large as the -glass, is required. A quantity of fluorspar is placed in it and is -moistened with concentrated sulphuric acid. The glass is placed face -downward over the tray. It is supported over the mixture by resting on -the edges of the tray or by any simple method, and the whole is covered -with a towel. In half an hour or more the etching will be completed. -The vapors must not be allowed to escape into any room containing -glass or metal articles as they corrode everything. Great care should -be taken also not to let the mixture touch the hand, as painful ulcers -are the result. - -_India Rubber Shoe Blacking._--Raw india rubber is given as a -constituent of several shoe blackings. Formulæ are given as below for -paste and liquid blackings. - -I. Paste blacking: bone-black, 20 parts; molasses, 15 parts; vinegar, -4 parts; sulphuric acid, 4 parts; caoutchouc oil (as given below), 3 -parts. - -II. Liquid blacking: bone-black, 60 parts; molasses, 45 parts; gum -arabic dissolved in water, 1 part; vinegar, 50 parts; sulphuric acid, -24 parts; caoutchouc oil, 9 parts. - -Caoutchouc oil is made by dissolving or digesting virgin rubber 55 -parts in linseed oil 450 parts. - -_Waterproof Composition for Boots._--One ounce of virgin rubber cut -into pieces is digested in enough oil of turpentine to form a stiff -paste. In applying heat take great care lest the contents of the vessel -become ignited. When homogeneous, which condition may be brought about -by rubbing in a porcelain mortar, as described in chapter XII., it is -mixed with 5–6 ounces of boiled linseed oil. This gives an ointment -almost of the consistency of butter. - - - - -INDEX. - - - PAGE - Absorption of sulphur process 100 - - Absorption of water by india rubber 31 - - Africa, ways of collecting rubber sap 15–17 - - Analysis of sap of india rubber tree 27 - - Apparatus for stamp making 61–63 - - Artists’ burned rubber 136–137 - - - Balloons 95 - - Bands, india rubber 41 - - Bicycle tyre cement 125 - - Blacking, india rubber 142 - - Borax and water solution of rubber 106–107 - - Brazil, ways of collecting sap 20–21 - - Bromine as vulcanizer 100 - - Bulbs, how made 92–93 - - Burned rubber, artists’ 136–137 - - - Calendering 43 - - Cane tips 90 - - Caoutchin 30 - - Caoutchoucin 30 - - Caoutchouc, (see India Rubber.) - - Cements 125–128 - - Clamp for vulcanizing press 52 - - Cohesion of rubber, its importance to the manufacturer 26–27 - - Cold curing 100–102 - - Composition for stamps and its moulding 113–120 - - Composition inking pad 118–119 - - Composition stamp handle 117–118 - - Cord, rubber 92 - - Corks 90–91 - - Curing 44 - - Curing, how to judge of completion of 70 - - Curing in liquid bath 97 - - Curing in sulphur bath 99 - - Curing, temperature of 58 - - Central America, ways of collecting rubber 18–19 - - Chair leg tips 90 - - Chalk plates 83–84 - - Chlorine as vulcanizer 100 - - Chloroform as a solvent 105 - - Coagulation of sap by a plant 19 - - Coagulation of sap by alum 22–23 - - Coagulation of sap by fire 21–22 - - Coagulation of sap by salt 18 - - Cohesion of pure rubber 25 - - - Dating stamps, composition 116–117 - - Didot’s polytype for matrices 82–83 - - Distillation products of india rubber 29–30 - - Dolls, how made 92–93 - - - Ebonite 108–111 - - Ebonite, polishing 110–111 - - Emery wheels and whetstones 139–140 - - Emulsion of caoutchouc 10 - - Etching 140–142 - - - Fins, removal of 86 - - Flask for type moulding 74 - - Flong matrices 80–82 - - Flong paste 80 - - Fluid for mixing with plaster for matrices 55 - - - Gas heated steam vulcanizer 53 - - Glue, marine 126 - - Glue stamps 113–120 - - Glycerine bath for curing 97 - - Goodyear, Charles 13–14 - - Gutta-percha 111–112 - - Gutta-percha, moulding 111–112 - - Gutta-percha, vulcanizing 111 - - - Hektograph, composition 121–122, 124 - - Hektograph, how made and used 121–124 - - Hektograph ink (also see inks) 121 - - Hektograph sheets 124 - - - India Rubber, absorption of water by 31 - - India rubber, African 15–17 - - India rubber, artists’ burned 136–137 - - India rubber, availability for small articles 85 - - India rubber, cohesion of unvulcanized 25 - - India rubber, composition of 27 - - India rubber, discovery of, etc. 11–13 - - India rubber, effects of temperature on 28–29 - - India rubber, elasticity of 29, 33 - - India rubber sap, its coagulation 11 - - India rubber sheet, how made 40 - - India rubbers, original way of making 10 - - India rubber stamp making without apparatus 71 - - India rubber stamps, home-made mould 48–50 - - India rubber stamps, starting point 47 - - India rubber, trees producing 9 - - India rubber tree sap, analysis of 27 - - India rubber type 73 - - India rubber, vulcanized, general properties of 32–33 - - India rubber, where collected 11 - - India rubber, inelastic, how made 31 - - India rubber, its mastication 38–40 - - India rubber, manufacture of 35–46 - - India rubber, necessity of drying 38 - - India rubber, points to be followed in moulding small articles 85 - - India rubber, preliminary operations in manufacturing 35–36 - - India rubber, preserving, etc. 134–135 - - India rubber, properties of 28 - - India rubber sap 9–11 - - India rubber stamp vulcanizing 58–60 - - Inelastic state of india rubber 31 - - Inks, special for stamping, etc. 129–133 - - Iodine and haloid vulcanizers 100 - - Isoprene 30 - - - Leaves, skeletonized as models 92 - - Liquid bath curing 97 - - - Machine for cutting sheet and threads 40 - - Machine for making mixed sheet 42–43 - - Machine for masticating 38–40 - - Machine for washing and sheeting 37 - - Mackintosh 13 - - Mackintoshes, how made 45–46 - - Marshmallow root for mixture with plaster 57 - - Masticated rubber, its easy solution 103–104 - - Masticating in mortar with benzole 103–104 - - Mastication of rubber 38–40 - - Materials mixed with india rubber 43 - - Matrices, various kinds of, for stamps 80–84 - - Matrix for stamp-making 54–55 - - Matrix making by casting 56–57 - - Matrix press 56 - - Matrix, process of making, for stamps 54–55 - - Mats 91–92 - - Metals, welding and cohesion of 25–26 - - Miscellaneous 134–142 - - Mixed sheet 42–44 - - Mixed sheet for stamps 47–48 - - Mould, home-made for stamps 48–50 - - Moulding and curing stamps 58–60 - - Moulds for composition stamps, temperature of 120 - - Moulds, material for 86 - - - Naptha and volatile solvents, danger of 107 - - Naptha, solvent 104–105 - - Nicaragua, ways of collecting sap 19–20 - - Nitric acid as vulcanizer 100 - - - Oil for composition stamp moulds 119–120 - - Oil for mould face 55 - - Oils fixed bad effect on solutions 105 - - Oxychloride of zinc cement for matrices 57 - - - Papier maché matrices 80–82 - - Paraffin and rubber 105–106 - - Parkes’ process 100–102 - - Payen’s solvent 105 - - Pencil tips, moulds for 89–90 - - Phenyle sulphide as softener of vulcanized rubber 106 - - Plaster, dental for matrices 54 - - Press for moulding stamps, etc. 51–52 - - Press, gas-heated 52–53 - - Press, home-made 49 - - Press, matrix making 55–56 - - Products, general division of 35–36 - - - Rods, stirring for laboratory 95 - - Rubber, origin of name 12 - - Rubber, see India Rubber - - - Salt bath for curing 98 - - Sap of india rubber tree, analysis of 27 - - Sheeting and washing 37–38 - - Sheet rubber, how made 40 - - Sheet rubber, its joining 94 - - Shellac for strengthening matrix 55 - - Shoes, blacking for 142 - - Shoes, india rubber, cement for 127 - - Siphonia, origin of name 11 - - Solution, different views of 31–32 - - Solution, difficulties of 103 - - Solvents for rubber 104–105 - - Spring chase for matrices 56 - - Springs for stamp moulds 51 - - Springs on moulding press 51 - - Sponge india rubber 137 - - Stamp making 47 - - Stamps, rubber, substitute for 138 - - Stamps, see India Rubber, Composition and general titles. - - Strauss’ method of coagulating sap 22–23 - - Suction discs, regular mould for 88–89 - - Suction discs, simple mould for 87–88 - - Sulphides, alkaline as vulcanizers 100 - - Sulphur, absorption process 100 - - Sulphur bath for mixing and curing 98–100 - - Sulphur chloride process 100–102 - - Sulphur, how mixed with gum 43 - - Sulphur, its escape from vulcanized rubber 33–34 - - Sunlight excluded from washed sheet rubber 38 - - Syringes made by Indians 11 - - - Test for curing with knife 48 - - Thread, rubber, cut 41 - - Thread, rubber, moulded 92 - - Tissues, coated, how made 45–46 - - Tubes, connecting glass 96 - - Tube, seamless 92 - - Turpentine, a solvent for vulcanized rubber 106 - - Turpentine compared with caoutchoucin 30 - - Turpentine, viscid nature of solution 104–105 - - Type, india rubber 73 - - Type moulding flask 74 - - Type and stamps from vulcanized rubber 77 - - Type, cutting apart 75 - - Type, points in moulding 75 - - Type, quads, and spaces for stamp models 71–72 - - Type, steel moulds for 76 - - - United States composition stamps 113–120 - - - Varnish shellac for india rubber 137–138 - - Vulcanite 108–111 - - Vulcanization, its two steps 42 - - Vulcanization, steps in process 47–48 - - Vulcanized rubber stamps and type 77 - - Vulcanizer 52–53 - - Vulcanizer, fish kettle as a 69–70 - - Vulcanizer, flower pot 68–70 - - Vulcanizer, chamber 63 - - Vulcanizing and moulding stamps 58–60 - - - Washing and sheeting 37–38 - - Water absorbed by india rubber 31 - - Waterproof composition for shoes 142 - - Waterproofing for battery cells 127–128 - - - Zinc, chloride 57 - - - - - - -Transcriber’s Notes - - -Punctuation, hyphenation, and spelling were made consistent when a -predominant preference was found in the original book; otherwise they -were not changed. - -Simple typographical errors were corrected; unbalanced quotation -marks were remedied when the change was obvious, and otherwise left -unbalanced. - -Illustrations in this eBook have been positioned between paragraphs -and outside quotations. In versions of this eBook that support -hyperlinks, the page references in the List of Illustrations lead to -the corresponding illustrations. - -The index was not checked for proper alphabetization or correct page -references. Three missing page references were added by the Transcriber. - -Page 26: “The relegation of ice” was printed that way. - -Page 40: “alkanine” may be a misprint for alkaline. - -*** END OF THE PROJECT GUTENBERG EBOOK RUBBER HAND STAMPS AND THE -MANIPULATION OF RUBBER *** - -Updated editions will replace the previous one--the old editions will -be renamed. - -Creating the works from print editions not protected by U.S. copyright -law means that no one owns a United States copyright in these works, -so the Foundation (and you!) can copy and distribute it in the -United States without permission and without paying copyright -royalties. Special rules, set forth in the General Terms of Use part -of this license, apply to copying and distributing Project -Gutenberg-tm electronic works to protect the PROJECT GUTENBERG-tm -concept and trademark. Project Gutenberg is a registered trademark, -and may not be used if you charge for an eBook, except by following -the terms of the trademark license, including paying royalties for use -of the Project Gutenberg trademark. If you do not charge anything for -copies of this eBook, complying with the trademark license is very -easy. You may use this eBook for nearly any purpose such as creation -of derivative works, reports, performances and research. Project -Gutenberg eBooks may be modified and printed and given away--you may -do practically ANYTHING in the United States with eBooks not protected -by U.S. copyright law. Redistribution is subject to the trademark -license, especially commercial redistribution. - -START: FULL LICENSE - -THE FULL PROJECT GUTENBERG LICENSE -PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK - -To protect the Project Gutenberg-tm mission of promoting the free -distribution of electronic works, by using or distributing this work -(or any other work associated in any way with the phrase "Project -Gutenberg"), you agree to comply with all the terms of the Full -Project Gutenberg-tm License available with this file or online at -www.gutenberg.org/license. - -Section 1. General Terms of Use and Redistributing Project -Gutenberg-tm electronic works - -1.A. By reading or using any part of this Project Gutenberg-tm -electronic work, you indicate that you have read, understand, agree to -and accept all the terms of this license and intellectual property -(trademark/copyright) agreement. If you do not agree to abide by all -the terms of this agreement, you must cease using and return or -destroy all copies of Project Gutenberg-tm electronic works in your -possession. If you paid a fee for obtaining a copy of or access to a -Project Gutenberg-tm electronic work and you do not agree to be bound -by the terms of this agreement, you may obtain a refund from the -person or entity to whom you paid the fee as set forth in paragraph -1.E.8. - -1.B. "Project Gutenberg" is a registered trademark. It may only be -used on or associated in any way with an electronic work by people who -agree to be bound by the terms of this agreement. There are a few -things that you can do with most Project Gutenberg-tm electronic works -even without complying with the full terms of this agreement. See -paragraph 1.C below. There are a lot of things you can do with Project -Gutenberg-tm electronic works if you follow the terms of this -agreement and help preserve free future access to Project Gutenberg-tm -electronic works. See paragraph 1.E below. - -1.C. The Project Gutenberg Literary Archive Foundation ("the -Foundation" or PGLAF), owns a compilation copyright in the collection -of Project Gutenberg-tm electronic works. Nearly all the individual -works in the collection are in the public domain in the United -States. If an individual work is unprotected by copyright law in the -United States and you are located in the United States, we do not -claim a right to prevent you from copying, distributing, performing, -displaying or creating derivative works based on the work as long as -all references to Project Gutenberg are removed. Of course, we hope -that you will support the Project Gutenberg-tm mission of promoting -free access to electronic works by freely sharing Project Gutenberg-tm -works in compliance with the terms of this agreement for keeping the -Project Gutenberg-tm name associated with the work. You can easily -comply with the terms of this agreement by keeping this work in the -same format with its attached full Project Gutenberg-tm License when -you share it without charge with others. - -1.D. The copyright laws of the place where you are located also govern -what you can do with this work. Copyright laws in most countries are -in a constant state of change. If you are outside the United States, -check the laws of your country in addition to the terms of this -agreement before downloading, copying, displaying, performing, -distributing or creating derivative works based on this work or any -other Project Gutenberg-tm work. The Foundation makes no -representations concerning the copyright status of any work in any -country other than the United States. - -1.E. Unless you have removed all references to Project Gutenberg: - -1.E.1. The following sentence, with active links to, or other -immediate access to, the full Project Gutenberg-tm License must appear -prominently whenever any copy of a Project Gutenberg-tm work (any work -on which the phrase "Project Gutenberg" appears, or with which the -phrase "Project Gutenberg" is associated) is accessed, displayed, -performed, viewed, copied or distributed: - - This eBook is for the use of anyone anywhere in the United States and - most other parts of the world at no cost and with almost no - restrictions whatsoever. You may copy it, give it away or re-use it - under the terms of the Project Gutenberg License included with this - eBook or online at www.gutenberg.org. If you are not located in the - United States, you will have to check the laws of the country where - you are located before using this eBook. - -1.E.2. If an individual Project Gutenberg-tm electronic work is -derived from texts not protected by U.S. copyright law (does not -contain a notice indicating that it is posted with permission of the -copyright holder), the work can be copied and distributed to anyone in -the United States without paying any fees or charges. If you are -redistributing or providing access to a work with the phrase "Project -Gutenberg" associated with or appearing on the work, you must comply -either with the requirements of paragraphs 1.E.1 through 1.E.7 or -obtain permission for the use of the work and the Project Gutenberg-tm -trademark as set forth in paragraphs 1.E.8 or 1.E.9. - -1.E.3. If an individual Project Gutenberg-tm electronic work is posted -with the permission of the copyright holder, your use and distribution -must comply with both paragraphs 1.E.1 through 1.E.7 and any -additional terms imposed by the copyright holder. Additional terms -will be linked to the Project Gutenberg-tm License for all works -posted with the permission of the copyright holder found at the -beginning of this work. - -1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm -License terms from this work, or any files containing a part of this -work or any other work associated with Project Gutenberg-tm. - -1.E.5. Do not copy, display, perform, distribute or redistribute this -electronic work, or any part of this electronic work, without -prominently displaying the sentence set forth in paragraph 1.E.1 with -active links or immediate access to the full terms of the Project -Gutenberg-tm License. - -1.E.6. You may convert to and distribute this work in any binary, -compressed, marked up, nonproprietary or proprietary form, including -any word processing or hypertext form. However, if you provide access -to or distribute copies of a Project Gutenberg-tm work in a format -other than "Plain Vanilla ASCII" or other format used in the official -version posted on the official Project Gutenberg-tm website -(www.gutenberg.org), you must, at no additional cost, fee or expense -to the user, provide a copy, a means of exporting a copy, or a means -of obtaining a copy upon request, of the work in its original "Plain -Vanilla ASCII" or other form. Any alternate format must include the -full Project Gutenberg-tm License as specified in paragraph 1.E.1. - -1.E.7. Do not charge a fee for access to, viewing, displaying, -performing, copying or distributing any Project Gutenberg-tm works -unless you comply with paragraph 1.E.8 or 1.E.9. - -1.E.8. You may charge a reasonable fee for copies of or providing -access to or distributing Project Gutenberg-tm electronic works -provided that: - -* You pay a royalty fee of 20% of the gross profits you derive from - the use of Project Gutenberg-tm works calculated using the method - you already use to calculate your applicable taxes. The fee is owed - to the owner of the Project Gutenberg-tm trademark, but he has - agreed to donate royalties under this paragraph to the Project - Gutenberg Literary Archive Foundation. Royalty payments must be paid - within 60 days following each date on which you prepare (or are - legally required to prepare) your periodic tax returns. Royalty - payments should be clearly marked as such and sent to the Project - Gutenberg Literary Archive Foundation at the address specified in - Section 4, "Information about donations to the Project Gutenberg - Literary Archive Foundation." - -* You provide a full refund of any money paid by a user who notifies - you in writing (or by e-mail) within 30 days of receipt that s/he - does not agree to the terms of the full Project Gutenberg-tm - License. You must require such a user to return or destroy all - copies of the works possessed in a physical medium and discontinue - all use of and all access to other copies of Project Gutenberg-tm - works. - -* You provide, in accordance with paragraph 1.F.3, a full refund of - any money paid for a work or a replacement copy, if a defect in the - electronic work is discovered and reported to you within 90 days of - receipt of the work. - -* You comply with all other terms of this agreement for free - distribution of Project Gutenberg-tm works. - -1.E.9. If you wish to charge a fee or distribute a Project -Gutenberg-tm electronic work or group of works on different terms than -are set forth in this agreement, you must obtain permission in writing -from the Project Gutenberg Literary Archive Foundation, the manager of -the Project Gutenberg-tm trademark. Contact the Foundation as set -forth in Section 3 below. - -1.F. - -1.F.1. Project Gutenberg volunteers and employees expend considerable -effort to identify, do copyright research on, transcribe and proofread -works not protected by U.S. copyright law in creating the Project -Gutenberg-tm collection. Despite these efforts, Project Gutenberg-tm -electronic works, and the medium on which they may be stored, may -contain "Defects," such as, but not limited to, incomplete, inaccurate -or corrupt data, transcription errors, a copyright or other -intellectual property infringement, a defective or damaged disk or -other medium, a computer virus, or computer codes that damage or -cannot be read by your equipment. - -1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right -of Replacement or Refund" described in paragraph 1.F.3, the Project -Gutenberg Literary Archive Foundation, the owner of the Project -Gutenberg-tm trademark, and any other party distributing a Project -Gutenberg-tm electronic work under this agreement, disclaim all -liability to you for damages, costs and expenses, including legal -fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT -LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE -PROVIDED IN PARAGRAPH 1.F.3. YOU AGREE THAT THE FOUNDATION, THE -TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE -LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR -INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH -DAMAGE. - -1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a -defect in this electronic work within 90 days of receiving it, you can -receive a refund of the money (if any) you paid for it by sending a -written explanation to the person you received the work from. If you -received the work on a physical medium, you must return the medium -with your written explanation. The person or entity that provided you -with the defective work may elect to provide a replacement copy in -lieu of a refund. If you received the work electronically, the person -or entity providing it to you may choose to give you a second -opportunity to receive the work electronically in lieu of a refund. If -the second copy is also defective, you may demand a refund in writing -without further opportunities to fix the problem. - -1.F.4. Except for the limited right of replacement or refund set forth -in paragraph 1.F.3, this work is provided to you 'AS-IS', WITH NO -OTHER WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT -LIMITED TO WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PURPOSE. - -1.F.5. Some states do not allow disclaimers of certain implied -warranties or the exclusion or limitation of certain types of -damages. If any disclaimer or limitation set forth in this agreement -violates the law of the state applicable to this agreement, the -agreement shall be interpreted to make the maximum disclaimer or -limitation permitted by the applicable state law. The invalidity or -unenforceability of any provision of this agreement shall not void the -remaining provisions. - -1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the -trademark owner, any agent or employee of the Foundation, anyone -providing copies of Project Gutenberg-tm electronic works in -accordance with this agreement, and any volunteers associated with the -production, promotion and distribution of Project Gutenberg-tm -electronic works, harmless from all liability, costs and expenses, -including legal fees, that arise directly or indirectly from any of -the following which you do or cause to occur: (a) distribution of this -or any Project Gutenberg-tm work, (b) alteration, modification, or -additions or deletions to any Project Gutenberg-tm work, and (c) any -Defect you cause. - -Section 2. Information about the Mission of Project Gutenberg-tm - -Project Gutenberg-tm is synonymous with the free distribution of -electronic works in formats readable by the widest variety of -computers including obsolete, old, middle-aged and new computers. It -exists because of the efforts of hundreds of volunteers and donations -from people in all walks of life. - -Volunteers and financial support to provide volunteers with the -assistance they need are critical to reaching Project Gutenberg-tm's -goals and ensuring that the Project Gutenberg-tm collection will -remain freely available for generations to come. In 2001, the Project -Gutenberg Literary Archive Foundation was created to provide a secure -and permanent future for Project Gutenberg-tm and future -generations. To learn more about the Project Gutenberg Literary -Archive Foundation and how your efforts and donations can help, see -Sections 3 and 4 and the Foundation information page at -www.gutenberg.org - -Section 3. Information about the Project Gutenberg Literary -Archive Foundation - -The Project Gutenberg Literary Archive Foundation is a non-profit -501(c)(3) educational corporation organized under the laws of the -state of Mississippi and granted tax exempt status by the Internal -Revenue Service. The Foundation's EIN or federal tax identification -number is 64-6221541. Contributions to the Project Gutenberg Literary -Archive Foundation are tax deductible to the full extent permitted by -U.S. federal laws and your state's laws. - -The Foundation's business office is located at 809 North 1500 West, -Salt Lake City, UT 84116, (801) 596-1887. Email contact links and up -to date contact information can be found at the Foundation's website -and official page at www.gutenberg.org/contact - -Section 4. Information about Donations to the Project Gutenberg -Literary Archive Foundation - -Project Gutenberg-tm depends upon and cannot survive without -widespread public support and donations to carry out its mission of -increasing the number of public domain and licensed works that can be -freely distributed in machine-readable form accessible by the widest -array of equipment including outdated equipment. Many small donations -($1 to $5,000) are particularly important to maintaining tax exempt -status with the IRS. - -The Foundation is committed to complying with the laws regulating -charities and charitable donations in all 50 states of the United -States. Compliance requirements are not uniform and it takes a -considerable effort, much paperwork and many fees to meet and keep up -with these requirements. We do not solicit donations in locations -where we have not received written confirmation of compliance. To SEND -DONATIONS or determine the status of compliance for any particular -state visit www.gutenberg.org/donate - -While we cannot and do not solicit contributions from states where we -have not met the solicitation requirements, we know of no prohibition -against accepting unsolicited donations from donors in such states who -approach us with offers to donate. - -International donations are gratefully accepted, but we cannot make -any statements concerning tax treatment of donations received from -outside the United States. U.S. laws alone swamp our small staff. - -Please check the Project Gutenberg web pages for current donation -methods and addresses. Donations are accepted in a number of other -ways including checks, online payments and credit card donations. To -donate, please visit: www.gutenberg.org/donate - -Section 5. General Information About Project Gutenberg-tm electronic works - -Professor Michael S. Hart was the originator of the Project -Gutenberg-tm concept of a library of electronic works that could be -freely shared with anyone. For forty years, he produced and -distributed Project Gutenberg-tm eBooks with only a loose network of -volunteer support. - -Project Gutenberg-tm eBooks are often created from several printed -editions, all of which are confirmed as not protected by copyright in -the U.S. unless a copyright notice is included. Thus, we do not -necessarily keep eBooks in compliance with any particular paper -edition. - -Most people start at our website which has the main PG search -facility: www.gutenberg.org - -This website includes information about Project Gutenberg-tm, -including how to make donations to the Project Gutenberg Literary -Archive Foundation, how to help produce our new eBooks, and how to -subscribe to our email newsletter to hear about new eBooks. |