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+*** START OF THE PROJECT GUTENBERG EBOOK 76987 ***
+
+
+
+
+
+Transcriber’s Notes:
+
+  Underscores “_” before and after a word or phrase indicate _italics_
+    in the original text.
+  Equal signs “=” before and after a word or phrase indicate =bold=
+    in the original text.
+  Small capitals have been converted to SOLID capitals.
+  Deprecated spellings have been preserved.
+  Typographical and punctuation errors have been silently corrected.
+
+
+
+
+                       SPAR-TORPEDO INSTRUCTIONS
+                                FOR THE
+                          UNITED STATES NAVY.
+
+                            [Illustration]
+
+                                 1890.
+
+                   PREPARED AT THE TORPEDO STATION,
+                          BY DIRECTION OF THE
+                          BUREAU OF ORDNANCE.
+
+                        TORPEDO STATION PRINT.
+                               MAY 1890.
+
+
+_These Torpedo Instructions, revised and prepared at the Torpedo
+Station by order of the Bureau of Ordnance, are approved for use in the
+Navy._
+
+                                    _W. M. FOLGER_,
+                                          _Chief of Bureau._
+
+    _Bureau of Ordnance_,
+           _May 1st, 1890._
+
+
+
+
+LIST OF PLATES.
+
+
+    PLATE.
+        I. Service Torpedo.—Pattern D.
+       II. Exercise Torpedo.—Pattern D.
+      III. Circuit-closer, Contact Torpedo.—Pattern B.
+       IV. Fig. 1. Ship‘s Secondary Spar.—Pattern A.
+        ”  Fig. 2. Boat‘s Secondary Spar.—Pattern A.
+        V. Contact Spar Leading-Wires.—Pattern B.
+       VI. Spar-Torpedo Boat-Fittings.—Pattern B.
+      VII. Junction of Tubes Forming Boat‘s Spar.—Pattern A.
+     VIII. Fig. 1. Detonator.
+       ”   Fig. 2. Detonator Block.
+       IX. Fig. 1. Permanent Wires.
+        ”  Fig. 2. Connections with Firing Key of “A” Machine.
+        ”  Fig. 3. Connections with Firing-Battery.
+        X. Fig. 1. Electric Switch.
+        ”  Fig. 2. Terminal.
+       XI. Heel Fittings for Ship‘s Spar.
+      XII. Ship‘s Spar Fittings.
+     XIII. Battery Cell.
+      XIV. Battery Tester.
+       XV. Fig. 1. Hand-Firing Key.—Pattern B.
+        ”  Fig. 2. Diagram Showing Hand-Firing Key in Circuit.
+      XVI. Fig. 1. “A” Machine and Firing Key Connected.
+       “   Fig. 2. ”C” Machine Connected.
+     XVII. Fig. 1. Firing Key, Short-Circuit.
+      ”    Fig. 2. Firing Key, Testing Circuit.
+      ”    Fig. 3. Firing Key, Firing-Circuit.
+    XVIII. Steam-Drier.
+
+
+
+
+CONTENTS.
+
+
+                                                                  PAGE.
+                              CHAPTER I.
+    Spar-Torpedo Outfit—General Description—Care and Preservation    1
+
+                              CHAPTER II.
+    Preparation of Torpedoes                                        17
+
+                             CHAPTER III.
+    Electrical Apparatus                                            27
+
+                              CHAPTER IV.
+    Gun-Cotton—How Packed—Stowage—Care—Inspection and Drying        39
+
+                               APPENDIX.
+    Duties of the Inspector of Ordnance—List of Articles in
+    Outfit—Weights—Stowage Space                                    51
+
+    INDEX                                                           59
+
+    PLATES                                                          69
+
+
+
+
+Spar-Torpedo Instructions.
+
+
+
+
+CHAPTER I.
+
+SPAR-TORPEDO OUTFIT.
+
+
+GENERAL DESCRIPTION.—CARE AND PRESERVATION.
+
+_Class D._—Includes one set of Ship‘s Torpedoes, Service and Exercise,
+one set of Boat‘s Torpedoes, Service and Exercise, and one set of
+circuit-closers and appurtenances for the conversion of Service into
+Contact Torpedoes.
+
+Service and Exercise Torpedoes are to be used from ships and boats;
+Contact Torpedoes from boats only.
+
+Many articles in a Torpedo Outfit are common to the different sets
+comprised in Class D, in which case similar articles are classed
+together for convenience of stowage and transportation. If the whole of
+Class D is not issued, then only a proportionate part of those articles
+designated as “Spare” are issued. Articles that belong exclusively to
+any one set are issued with that set only.
+
+
+SERVICE TORPEDO.
+
+=Pattern D.—Plate I.=
+
+(Twenty-four are issued.—Twelve for use from ships and twelve from
+boats.)
+
+This torpedo, intended for use from either ships or boats, is 12⅜
+inches long and 9 inches square, inside measurement, and is made of
+sheet iron tinned inside and out, coated inside with shellac and
+painted outside with asphaltum. Around a filling hole in the top is
+soldered a brass ring having on its inner circumference, a screw-thread
+for a brass screw-cover which bears a stuffing-box for the entrance
+of the spar leading-wires. A rubber washer between the cover and ring
+makes the case water-tight. Riveted to the top is a tinned malleable
+iron frame fitted with four lugs. A handle secured to two of the
+lugs forms a brace for the spindle that attaches the torpedo to the
+secondary spar; this spindle has two curved arms at one end that
+straddle the handle and secure to the other two lugs by screw-bolts, a
+projection on the crown of the handle fitting into a recess in the stem
+of the spindle. To the bottom of the case is riveted a tinned malleable
+iron plate for attaching a circuit-closer.
+
+The primer-case, 8⅛ inches long and 3 inches square, inside
+measurement, is made of tin coated inside and out with shellac and is
+closed at one end.
+
+The torpedo-case, empty but complete except the spindle, weighs about
+15 lbs. The charge of the torpedo, including the primer of 2½ lbs. of
+dry gun-cotton, is equivalent to about 34 lbs. of dry gun-cotton.
+
+When issued, the torpedo-cases are completely filled with wet
+gun-cotton, the screw-cover is screwed down tight and the hole in the
+stuffing-box is closed tight by screwing down the water-cap over the
+spherical rubber packing placed sideways in its seat.
+
+
+EXERCISE TORPEDO.
+
+=Pattern D.—Plate II.=
+
+(Twelve are issued, two of which are empty, for use from ships or
+boats).
+
+This torpedo, 12½ inches long and 3¹/₁₆ inches square, inside
+measurement, is made of tin and is closed at the lower end. It is
+coated inside and out with shellac. To the upper end is soldered a
+brass flange having a loop on one side and a throw-back hinge on
+the opposite side. The cover consists of a square brass plate with
+two loops one of which rests over the loop on the flange, the other
+receiving the lug of the throw-back hinge. A thumb-screw, fitted to
+the end of the lug, secures one side of the cover and a transportation
+thumb-screw, fitted to the loops, secures the other side. The cover
+bears a stuffing-box for the entrance of the spar leading-wires. A
+rubber washer between the cover and flange makes the case water-tight.
+A loop is fitted to one side of the case to receive the lower end of
+the spindle.
+
+The weight of this torpedo, empty but complete, except the spindle, is
+3¼ lbs. and its charge is equivalent to about 4 lbs. of dry gun-cotton.
+
+When issued, all the exercise torpedo-cases, except two, are completely
+filled with wet gun-cotton, the cover is closed tight and the hole in
+the stuffing-box is closed tight by screwing down the water-cap over
+the spherical rubber packing placed sideways in its seat.
+
+
+STUFFING-BOXES.
+
+=Plates I. and II.=
+
+Stuffing-boxes provide a water-tight entrance for the spar
+leading-wires through the covers of the torpedo-cases.
+
+In the center of each cover, around the hole for the entrance of the
+leading-wires, is a brass rim fitted with a screw-thread outside, and
+bored out, inside, with a slightly conical taper, providing a seat for
+the packing.
+
+The packing is of partly vulcanized rubber, 1 inch in diameter,
+spherical in shape, with two parallel holes, each ¼ inch in diameter,
+for reeving the leading-wires.
+
+The water-cap screws on the brass rim and compresses the packing in its
+seat, a friction-ring in the top of the cap preventing twisting of the
+packing when screwing down.
+
+A hole, ⅝ inch in diameter, through the top of the water-cap, permits
+reeving the spar leading-wires.
+
+When rubber packing is to be left seated for a long time the seat for
+the packing should be coated with shellac and the packing brushed with
+black lead to prevent adhesion.
+
+
+CIRCUIT-CLOSER.—CONTACT TORPEDO.
+
+=Pattern B.—Plate III.=
+
+(Four are issued, to convert Service Torpedoes into Contact Torpedoes,
+for use from boats.)
+
+The circuit-closer consists of a cylindrical brass casting, having
+one end closed, and on this end are four feet by which it is secured
+to the lower head of the service torpedo by screws. The cylinder,
+4¾ inches long and 5 inches in diameter, is closed at the open end
+by a screw-cover, having four lugs that serve as bearings for the
+contact-arms; these arms, four in number, work in slots cut in a
+plunger that passes through the center of the cap, and they are held in
+place by screws through the ends of two arms and their lugs. Inside the
+cylinder are two insulated contact-springs secured to binding-posts in
+an ebonite collar. This collar screws on the end of a short brass tube
+that carries a plunger tipped on the inner end with ebonite. A stout
+spiral spring in the tube through which passes this plunger, maintains,
+normally, the end of the plunger clear of the contact-springs. A
+rubber diaphragm separates the plunger in the cover from the plunger
+in the tube, and also acts as a washer to the cover, making the
+cylinder water-tight; a brass washer, laid on this diaphragm, acts as a
+friction-plate for the cover to turn on when screwed up. A safety-pin
+through the outer plunger prevents its being forced in accidentally.
+When this pin is withdrawn, any pressure on the contact-arms tends to
+force the inner plunger in against the action of the spiral spring and
+to close the break between the contact-springs.
+
+The break is ³/₁₆ inch and the tension of the spiral spring is 75 lbs.
+
+On the side of the cylinder is fitted a stuffing-box furnishing a
+water-tight entrance for the leading-wires to the binding-posts of the
+contact-springs.
+
+The circuit-closer, complete, weighs 7 lbs.
+
+
+SECONDARY SPARS.
+
+=Pattern A.—Plate IV.=
+
+(One is furnished for each Service Torpedo.)
+
+These are iron pipes, 8 feet long. Those for ships‘ use have a slot
+cut in one end, for a key. Those for use in boats are fitted at one
+end with an iron disc, called a butt, and at 2 feet 2 inches from the
+butt an iron cap is riveted to the spar. All secondary spars have, at 5
+inches from the outer end, a hole for the torpedo-pin. Secondary spars
+are packed six in a box; those for ships having a key stopped to each
+to be used in securing the secondary spar to the inner spar-band; those
+for boats having a toggle stopped to each to be used in securing the
+secondary spar to the boat spar.
+
+
+TORPEDO PINS.
+
+=Plate IV.=
+
+Torpedo pins are short iron pins with an eye in one end, to which a
+spun-yarn tail is spliced, designed to secure torpedoes to secondary
+spars. One is provided for each service and exercise torpedo. They are
+packed, with the spindles, in Box 53.
+
+
+REEL BOX.
+
+This contains 300 feet of insulated double-conductor wire cable. The
+inner ends of the cable are connected to binding-screws on the sides of
+the reel, where short wires are to be attached, for making connections
+with batteries, etc., after the requisite amount of cable has been
+unreeled. A handle is becketed to the cover of the box, to be used in
+reeling up the cable. The binding-screws must be kept free from rust
+(no oil to be used in cleaning), and must be occasionally turned to
+keep them from setting.
+
+The cable, as now issued, consists of two cores, each core composed of
+seven No. 22 A. W. G. copper wires of not less than 95% conductivity,
+coated with tin and laid up in a strand. Each core is separately
+insulated with okonite composition to an external diameter of ¼ inch
+and is wrapped with tape soaked in okonite composition. The two
+insulated cores, laid side by side, are covered with hemp braiding to
+protect them from chafe.
+
+The resistance of the core is 2.2 ohms per 1000 feet.
+
+The cable in the reel box is for general use and to replace disabled
+permanent wires. It must never be subjected to a strain of over 100
+pounds, nor jerked or hauled in from any length, but under-run.
+
+The cable must be stowed in a cool, dry place.
+
+
+SHIP‘S WIRE-BOX.
+
+This box is marked “Wire-Box—Ship‘s.” It contains four spar
+leading-wires of insulated double-conductor copper wire cable, 70 feet
+each in length, precisely similar to that found in the reel box, and
+two machine-connecting wires 12 feet each in length.
+
+The spar leading-wires are to connect the torpedo with the terminals of
+the permanent wires. To guard against mistakes in making connections
+those for use on the starboard side are painted green and marked with
+one knot and those for use on the port side are painted red and marked
+with two knots.
+
+The machine-connecting wires are insulated wires for connecting the D.
+E. machine, Pattern A., with the firing-key and for general purposes.
+
+
+BOAT‘S WIRE-BOX.
+
+This box is marked “Wire-Box—Boat‘s.” It contains the same articles as
+“Wire-Box—Ship‘s,” similarly marked.
+
+
+CONTACT SPAR LEADING-WIRES.
+
+=Pattern B.—Plate V.=
+
+These consist, practically, of three insulated copper wire cables which
+lead, in use, as follows:—1st. wire, from the detonator to one terminal
+of the battery; 2nd. wire, from the circuit-closer to the second
+terminal of the battery _via_ the safety-break; 3rd. wire, branching in
+two legs at its outer end, from the detonator and the circuit-closer to
+the second terminal of the battery _via_ the hand-firing key and the
+safety-break.
+
+The safety-break and the hand-firing key are connected to their proper
+leads by wires of convenient length to permit placing the battery out
+of the way when connected up.
+
+The safety-break consists of two round, tapering pieces of brass each
+fitted with a score and two small holes in the smaller end to which the
+leading-wire is permanently secured. The larger ends, fitted to ship
+together bayonet fashion, can be readily connected or disconnected at
+pleasure.
+
+Directions for using these wires are given in “Preparation of Contact
+Torpedo.”
+
+
+SPAR-BANDS.
+
+=Plate IV.=
+
+These, of wrought iron, furnish a ready means of securing secondary
+spars to the ordinary wooden torpedo-spars supplied to ships. These
+bands, with loops on top, are secured to the end of the wood spar, 3
+feet apart, with wood screws. The inner band has a key-way, to hold
+the secondary spar in place. Care must be taken that the loops of both
+bands are exactly in line.
+
+
+SUPPLY-BOX.
+
+This box, containing tools and small articles required in spar-torpedo
+work, is marked on top, “Torpedo Supply-Box.” For contents see Box 3
+“List of Articles in Outfit supplied from Torpedo Station.”
+
+
+BOAT-FITTINGS.
+
+=Pattern B.—Plate VI.=
+
+These, for the support and handling of the boat spars, consist of
+bow-fittings, 2 swivel-crutches and 2 heel-rests.
+
+The heel-rest is an iron crutch bolted to the rail well aft. A hinge
+allows the rest to be laid inboard when not in use.
+
+The swivel-crutch is a square iron collar fitted with a shank that
+turns freely in a bearing firmly bolted to the rail, 9 feet abaft the
+cross-beam. The collar is made in two parts, the upper one working on a
+hinge, and has two rollers.
+
+Bow-fittings consist of a cross-beam with its attachments. The
+cross-beam, made of heavy wrought-iron tubing, is secured across the
+bow to castings let into the rail. On sleeves, at the ends of the
+cross-beam, are elevating-arms free to revolve in a vertical plane. At
+the outer end of each arm a swivelled guide-ring is placed, projecting
+at right angles to the arm in the direction of the beam of the boat.
+In the lower part of this ring is a roller. Connected with the sleeve
+of each arm is a gear moved by a worm on the forward end of a shaft
+extending aft into the boat, an elevating-wheel being keyed to the
+after end of the shaft.
+
+The worm-shaft is in two lengths joined by a hook-coupling interposed
+near the forward end of the shaft to allow the worm sufficient play to
+engage the gear of the elevating-arm during the revolution of the shaft.
+
+The worm-shaft is allowed a fore-and-aft motion such that, when
+the shaft is forward, the worm is disengaged from the gear of the
+elevating-arm, leaving it unsupported and free to drop and, when
+the shaft is aft, the worm is engaged with the gear so that the
+elevating-arm may be controlled by the elevating-wheel.
+
+The shaft is held aft by a clutch placed just forward of the
+elevating-wheel. The clutch consists of a sleeve, supported on
+trunnions by a bearing bolted to a chock on the forward deck of the
+boat, carrying a yoke-link, loosely bolted to two lugs on its forward
+lower end and a detaching-lever, loosely bolted to two lugs on its
+forward upper end. The worm-shaft, passing through this sleeve, bears a
+rigid collar so placed that, when the shaft is aft, the collar is close
+up against the forward end of the sleeve. The yoke-link, when swung up,
+embraces the shaft and bears against the forward side of the collar,
+holding the shaft aft. The yoke-link is held up by the detaching-lever
+which is thrown forward between the upper ends of the yoke-link, a
+transverse roller in the detaching-lever, with ends projecting on
+either side, locking the yoke-link in place. A pin, passed through
+eyes worked in the upper ends of the yoke-link, prevents accidental
+tripping of the detaching-lever. When this pin is withdrawn and the
+detaching-lever is pulled aft the yoke-link falls and the shaft is free
+to move forward.
+
+By the worm-shaft and its attachments the elevating-arm can be rotated
+around the cross-beam, held in any position in its plane of rotation,
+or released at any desired moment.
+
+The gear and worm are protected by hoods.
+
+
+BOAT SPARS.
+
+=Pattern A.—Plate VII.=
+
+The spar, made of steel, consists of two tubes, 18 and 15 feet long
+respectively, one 4 inches and the other 3½ inches in diameter, joined
+together with a telescopic joint. The tubes—with a lap of 2 feet—are
+held together by two screws. At the larger end of the spar is an
+eye-bolt for the heel-rope screwed in from the inside, and at 5 feet
+from the smaller end is a hole for reeving the spar leading-wires.
+This constitutes the main spar, which can readily be taken apart for
+stowage by removing the screws. To assemble the spar, a feather fits
+into a score on the end of the larger tube, bringing the screw-holes
+opposite each other. Iron spar-clamps are furnished, to facilitate the
+assembling of the spar.
+
+The two tubes composing each spar are marked by similar letters or
+numbers.
+
+=_Note._=—Spars must invariably be taken apart after use, joints
+lubricated, and protected by a canvas cover.
+
+
+DETONATORS.
+
+=Plate VIII.=
+
+Detonators are cylindrical copper cases, closed at the bottom,
+containing 35 grains of fulminate of mercury, primed on top with dry,
+pulvurulent gun-cotton.
+
+A plug, made of 1 part of ground glass and 2 parts of sulphur, melted
+together, is cast around the detonator-legs:—tinned copper wires, No.
+20 A. W. G., 6 inches in length, insulated with a double layer of
+cotton thread soaked in paraffine, the outer layer colored red.
+
+The inner ends of the detonator-legs are bridged by a platinum-iridium
+wire, 90% platinum, 10% iridium, ³/₁₆ inch long and 2 mils in diameter,
+having a resistance of .65±.03 ohm.
+
+The plug is inserted in a copper band; dry pulvurulent gun-cotton is
+loosely packed about the bridge and on top of the fulminate of mercury
+and the band is screwed on the upper end of the detonator-case, thus
+closing it.
+
+Detonators are painted red. They are supplied for use with gun-cotton
+torpedoes.
+
+
+DETONATOR BLOCKS.
+
+=Plate VIII.=
+
+Wooden cylinders, with a cover that has a small circular motion. Each
+block holds 8 detonators placed in holes around the circumference, the
+cover locking them in. Each block is placed in a covered tin cylinder
+painted red and marked “Dangerous.” These blocks will be placed in
+different parts of the ship, never below the water-line. (See Ord.
+Inst.)
+
+
+DUMMY DETONATORS.
+
+These are empty detonator-cases, with a hole bored in the bottom, for
+use in making connections in practice. The detonator-legs are not
+bridged but are cast in the plug on the bight.
+
+Dummy detonators are painted white and the legs are insulated with
+white cotton thread.
+
+
+IGNITERS.
+
+Igniters are cylindrical brass cases, closed at the lower end,
+containing a charge of rifle gunpowder.
+
+The upper end is closed by inserting a plug precisely similar to that
+used in detonators, except that the igniter-legs are insulated with
+white cotton thread instead of red.
+
+The bridge is primed by twining about it a wisp of long-staple, dry
+gun-cotton.
+
+Igniters are coated with white shellac. They are supplied for use with
+improvised gunpowder torpedoes.
+
+
+GUN-POWDER FUZES.
+
+These are stout, cylindrical, paper cases, closed at the lower end and
+charged with rifle gunpowder. In the center of the charge is placed an
+igniter the legs of which project on either side of a wooden plug which
+is seized in the upper end of the case to close it.
+
+Igniters are coated with orange shellac.
+
+A rubber insulator, for preventing short-circuit between the splices
+when the fuze is attached to leading-wires, is seized around the upper
+end of the case.
+
+Fuzes are supplied for use with improvised gunpowder torpedoes.
+
+
+BOX CONTAINING GUN-POWDER FUZES AND IGNITERS.
+
+This is marked with a list of contents. It is packed in Box 7, from
+which it is to be removed, when received aboard ship, and stowed in the
+magazine or ammunition room.
+
+
+GLASS JARS FOR DRY PRIMERS.
+
+=Pattern B.=
+
+Glass cylindrical jars, fitted with cork covers, each having a capacity
+for 6 two-inch, or 24 one-half inch blocks of gun-cotton. These
+blocks of dry gun-cotton are tied together with boiled tape and have
+litmus-paper between them. They are never to be stowed below, but
+must be placed in different parts of the ship above the water-line.
+Being glass, the jar, without being opened, renders the litmus-paper
+readily discernible. Each jar is placed in a wooden case fitted with a
+sliding cover, painted white, and is stencilled with contents, and with
+precautions.
+
+The dry primers, as used, are replaced by drying the wet blocks removed
+from the torpedoes in priming them.
+
+
+GUN-COTTON DRYING APPARATUS.
+
+=Plate XVIII.=
+
+A steam-drier, for drying wet gun-cotton for use as primers, consists
+of a sheet-iron box containing two removable galvanized-iron wire
+baskets in which the blocks to be dried are supported, strung on rods.
+The blocks are separated from each other by small iron washers, ¼ inch
+thick, also strung on the rods, to permit free circulation of the air.
+A door in the front of the box permits entering and withdrawing the
+baskets.
+
+In the bottom of the box is a flat of steam-pipe the two ends of which,
+projecting from the side, are screw-threaded for ready connection
+with steam-heating apparatus, or with any other convenient source of
+low-pressure steam.
+
+A wire-gauze bottom, below the flat of steam-pipe, permits the entrance
+of air and serves to keep out dust and to prevent undue radiation of
+heat toward the outside.
+
+In the top of the box is a ventilating opening, with a rotary damper,
+protected by a hood, and also a hole for the introduction of a
+thermometer.
+
+
+CHEMICAL BOX.
+
+This box is marked on top “Chemical Box.” For contents see Box 16,
+“List of Articles in Outfit supplied from Torpedo Station.” For use of
+contents see “Inspection of Gun-Cotton.”
+
+The outfit includes a number of spare washers, spherical packings,
+diaphragms, etc., to supply necessary waste.
+
+In addition to the articles already mentioned, every vessel having a
+“Ship‘s and Boat‘s” spar-torpedo outfit is supplied from the Torpedo
+Station with the following articles, to be placed on board at the
+navy yards, as permanent fittings; viz.:
+
+Double-conductor insulated copper wire, incased in lead, in such
+quantity as may be required for permanent wires; 2 electric switches;
+13 terminal binding-screws.
+
+
+PERMANENT WIRES.
+
+=Plate IX.=
+
+In order to do away with the inconvenience of leading out lengths of
+wire from place to place, and to avoid injury to the wire, permanent
+wires are put in place when the ship is fitted out. These wires are
+led from terminals conveniently placed for battery connections via the
+electric switches or firing apparatus to the terminals, abreast the
+heels of the torpedo-spars.
+
+Permanent wires should be protected from hostile fire, from chafe,
+wear, and the sun; should never be taut; should never be led around
+sharp angles; metal staples should never be used to hold the wires
+in position, even temporarily; no part of the copper wire should be
+exposed to the action of salt water; splices should be soldered and
+carefully insulated; and the wires should be boxed in throughout their
+lengths.
+
+
+ELECTRIC SWITCHES.
+
+=Plate X.=
+
+In connection with permanent wires electric switches are used, and are
+permanently placed in a suitable position before a ship leaves the
+navy-yard.
+
+Their object is to connect the firing-battery or the firing-key of the
+D. E. machine with any or all the torpedoes. The plate represents the
+switch in position, on the starboard side, with the battery off, or
+the wires from the firing-key disconnected from any permanent wire,
+electrically. The switch should be protected from salt water and the
+weather as much as possible. It is thought best to inclose it in a box,
+as nearly water-tight as possible, provided with a door which opens in
+front.
+
+=_Note._=—Where permanent firing apparatus is furnished, the electric
+switches will not be issued.
+
+
+TERMINALS.
+
+=Plate X.=
+
+Terminals are ordinary brass binding-screws secured to base-pieces
+of black walnut which are to be secured in position by screws. The
+figure illustrates the manner of making permanent and temporary
+connections with the terminals. The counter-sunk space in the back of
+the base-piece is to be filled with melted wax, after the permanent
+wire has been attached, before securing the terminal in place. The
+binding-screws must be kept clean and free from paint.
+
+
+ARTICLES OF TORPEDO OUTFIT SUPPLIED AT NAVY YARDS.
+
+=Ship‘s Spars.=—Such ship-rigged vessels as are now fitted for
+spar-torpedoes are supplied with four torpedo-spars, fitted two on
+each side, abreast the foremast and mizzenmast. Barque-rigged vessels
+are supplied with but two spars, fitted one abreast the foremast on
+each side. The present regulation spar is of hickory or oak, 45 feet
+long, 8 inches in diameter at the heel, and 6 inches at the outer end.
+It should be of the best material, straight-grained, and as nearly as
+possible a natural-growth pole. In working down a larger spar, care
+should be observed to follow the grain of the wood. Yellow oak is
+considered superior for torpedo-spars. Red oak is too brash.
+
+=The Heel Fittings.= (_Plate XI._)—The thrust-plate is placed at
+about the height of the channels, in accordance with the regulations
+established by the Bureau of Ordnance. Discretion must be used in
+so placing this as to allow the spar to come alongside, so that the
+torpedo can be shipped from the rail or from a port. The elbow of the
+heel-bolt transmits the recoil of the spar to the thrust-plate, without
+injury to the bolt itself. Good results have been obtained by using a
+lashing of 6 turns of 3½-inch manilla, in place of the shackle, the
+elasticity of the rope serving to take up a portion of the thrust of
+the spar. An excellent plan is to secure the heel of the spar to a
+spare eye-bolt in the channels, as shown in Fig. 2.
+
+=The Spar Fittings.= (_Plate XII._)—The most approved method of fitting
+a torpedo spar with guys and topping lift is shown in the plate. Spans
+are fitted to the spar on which the forward guy and topping lift
+travel freely, and these spans are rove through lizards to divide the
+strain along the spar and prevent vibrations. The forward guy should
+be single, with as much drift as possible, and long enough to let the
+spar trail aft, after the explosion. The forward guy, the pendant of
+the topping lift, or that part of it secured to the span, the spans and
+lizards should be of galvanized-iron wire rope, ⅝ inch in diameter. The
+after guy may be a single part of small manilla rope, say 3-inch. The
+forward guy should be led from as near the water-line as possible to
+keep the spar from rising.
+
+
+
+
+CHAPTER II.
+
+PREPARATION OF TORPEDOES.
+
+
+SERVICE TORPEDO.
+
+=Pattern D.—Plate I.=
+
+=Priming the Service Torpedo.=—Take the torpedo out of its box; remove
+the screw-cover of the case and take out the wet gun-cotton found in
+the primer-case; wipe the primer-case dry and insert a primer of 16
+one-half inch blocks, or 4 two-inch blocks of dry gun-cotton.
+
+The wet gun-cotton removed from the primer-case is to be put in one of
+the empty exercise torpedo-cases and dried when opportunity offers.
+
+Wipe the screw-thread carefully and screw down tight the cover on its
+washer, taking care not to cut it, using the open-end wrench provided
+for the purpose in the supply-box. _It is absolutely necessary that
+this case be closed water-tight._
+
+=_Note._=—It is not advisable to prime torpedoes for a much longer
+time before using than the exigencies of the service require, although
+experiments at the Torpedo Station show that service gun-cotton
+torpedoes may remain primed for three months, under service conditions,
+and yet be relied upon to explode.
+
+=Testing the Detonator.=—Select a detonator, brighten the ends of
+its legs and attach them to leading-wires. _Put the detonator in
+a safe place_, connect the leading-wires to the terminals of the
+testing-magneto and turn the crank. Rattling of the armature will
+indicate continuity of the circuit and is presumptive evidence that
+the detonator is good. The wires from the detonator can be taken to
+the binding-posts T, T of the firing-key of the A machine and tested, a
+deflection of the needle furnishing proof of continuity (_Plate XVI_);
+or they can be taken to the terminals of the C machine which will
+indicate continuity by the striking of its gong. (_Plate XVI_).
+
+=Splicing on the Detonator.= (_Plates I and II._)—The detonator
+should now be spliced to the spar leading-wires. In splicing on the
+detonator, so arrange the length of wire that the spherical rubber
+packing can be placed on the leading-wires five inches from the bottom
+of the detonator-case, the splices being between the detonator and
+the packing. Remove the water-cap from the screw-cover of the case.
+Strip the braiding and rubber tape from the leading-wires for at least
+six inches from their ends and put on a neat whipping, which shall be
+outside the packing.
+
+Reeve the ends of the leading-wires through the water-cap and rubber
+packing. Remove so much of the insulation as may be necessary, for
+making the splice, from the leading-wires and from the legs of
+the detonator; brighten the wires and place the insulation of the
+detonator-legs alongside that of the leading-wires, with the ends of
+the insulation flush, and expend the bare detonator-legs in turns
+at right angles around the leading-wires. Turn the ends of the
+leading-wires back over the splices, and trim off the ends. _One splice
+should be one-half inch from the detonator and the other one inch from
+the packing._ Insulate from metallic contact the splice nearest the
+packing with twine and pass several turns about the wires until the
+detonator is reached, where the end of the twine is secured. A strip of
+okonite tape can be used, taking care that the insulation is not too
+bulky. (See sample splice in supply-box).
+
+=Fuzing the Service Torpedo.= (_Plate I._)—Having lined the holes of
+the dry blocks with the rectifier, to be found in the supply-box,
+enter the detonator through the hole in the cover and push it in until
+the packing is seated; screw up the water-cap hand-tight. Provide the
+spindle, to be found in Box 53, and secure it to the torpedo-case.
+
+=Shipping the Secondary Spar.= (_Ship‘s._)—Enter the end of the
+secondary spar in the loop of the outer band, and push in until the
+key-way is abreast the slot in the loop of the inner band; then put in
+the key and stop it in.
+
+=Shipping the Service Torpedo.= (_Ship‘s._)—Insert the stem of the
+spindle in the outer end of the secondary spar and push it home as far
+as the shoulder. Put in the torpedo-pin and stop it in.
+
+To prevent the strain of towing from starting the splice, turn
+a cuckold‘s-neck in the spar leading-wires, and lash it to the
+secondary spar or to the spindle, clear of the torpedo-case. The spar
+leading-wires should then be led in along the ship‘s spar, abaft the
+topping lift, and stopped to it at intervals of about four feet.
+
+=Fuzing and Shipping the Service Torpedo, and Shipping the Secondary
+Spar.= (_Boat‘s._) =Pattern B. Boat-Fittings.=—See that the
+elevating-arm points aft. Rig in the main spar clear of the guide-ring.
+Point the inner end of the secondary spar through the guide-ring,
+the outer end resting on the rail. Reeve the leading-wires through
+the guide-ring from forward aft, and fuze the torpedo. Then ship
+the torpedo in the secondary spar, securing it by the torpedo-pin,
+which must be stopped in. Turn a cuckold‘s-neck in the leading-wires
+and stop it to the secondary spar or to the spindle, clear of the
+torpedo-case. Slew the secondary spar in position, butt aft. Reverse
+the elevating-arm, by revolving it downward, until the guide-ring is in
+line with the swivel-crutch and heel-rest, carefully tending the inner
+end of the secondary spar by a line bent on. Ship the secondary spar
+in the main spar, by rigging the latter out or in, and secure it by a
+toggle, which must be stopped in.
+
+The boat spar leading-wires are rove through the main spar. To
+facilitate this, a reeving-line and weight, found in the supply-box, is
+rove through the main spar, before the secondary spar is shipped; one
+end of the line is secured to the heel-bolt, and the other around the
+spar abreast the wire-hole.
+
+When the secondary spar is shipped, bend the end of the leading-wires
+to the reeving-line, rig out the torpedo until the heel of the spar is
+conveniently placed for hauling on the after end of the reeving-line,
+and reeve the leading-wires through the spar, being careful to avoid
+chafing the insulation.
+
+When the contact spar leading-wires are used they must be rove through
+the main spar, from aft forward, before fuzing the torpedo.
+
+The spar leading-wires from the heel of the ship‘s spar are taken
+to the terminals abreast the heel of the spar; from the heel of the
+boat‘s spar they are taken directly to the C machine, or to the
+firing-battery, a hand-firing key being interposed when the battery is
+used. (_See Plate XV._)
+
+_No connection, however, is to be made with terminal, machine, or
+battery, until the torpedo is submerged and at the proper distance from
+the side of the ship or boat._
+
+=Testing the Circuit from Ships.=—After the torpedo is submerged the
+circuit may be tested, to do which connect the spar leading-wires
+to their proper terminals and connect the binding-screws T, T, of
+the firing-key, to the proper permanent wires. Place the firing-key
+as directed for testing the detonator, ship the crank of the D.
+E. machine, turn rapidly with the sun, and press the key T of the
+firing-key. A deflection of the compass-needle will indicate that the
+circuit is complete. (_See Plate XVI._) Or, the testing-magneto may be
+used to test the circuit.
+
+_The firing-battery must not be used to test the circuit._
+
+=To Fire.=—Make connections with the firing-battery, or with the A
+machine (_Plate IX_). When using the battery, close the hand-firing key
+at the moment it is desired to fire. When using the A machine, press
+the key F of the firing-key, and keep it down; turn the crank of the
+machine rapidly, and at the instant it is desired to fire, press firmly
+the key T of the firing-key (the key F being already down).
+
+The Service Torpedo must be immersed 10 feet, and from ships may be
+safely exploded at 35 feet from the side.
+
+=To Test the Circuit from Boats.=—The spar leading-wires are brought
+directly to the machine, (_See Plate XVI_), _but not connected until
+the torpedo is submerged_, when the circuit may be tested by connecting
+it to the binding-screws of the C machine, turning the crank of the
+machine and pressing the key T, as for testing the detonator. Or, the
+testing-magneto may be used to test the circuit.
+
+_The firing-battery must not be used to test the circuit._
+
+=To Fire.=—Make connection with the battery (_Plate XV_), or with the
+C machine (_Plate XVI_.) When using the battery, close the hand-firing
+key at the desired instant. When using the C machine, manipulate the
+keys as directed for the firing-key of the A machine.
+
+The Service Torpedo must be immersed not less than 10 feet, and may be
+safely exploded at a horizontal distance of 22 feet from the boat.
+
+
+EXERCISE TORPEDO.
+
+=Pattern D.—Plate II.=
+
+=Priming the Exercise Torpedo.=—Remove the transportation thumb-screw
+and loosen the thumb-screw on the lug of the hinge. Throw back the
+cover, replace the second wet block of gun-cotton from the top with
+a dry 2-inch block, or four ½inch blocks, and put the cover back in
+place; insert the spindle, to be found in box 53, through the loops on
+one side and screw down taut against its shoulder; screw down also the
+thumb-screw on the lug of the hinge. _It is absolutely necessary that
+this case be closed water-tight._
+
+The wet gun-cotton removed is to be placed in one of the empty exercise
+torpedo-cases, to be dried when opportunity offers.
+
+=_Note._=—Do not allow the dry primer to remain in the exercise torpedo
+any considerable length of time before use, as it may absorb enough
+moisture to prevent detonation.
+
+The detonator is tested and spliced, and the torpedo fuzed in the same
+manner as directed for the Service Torpedo.
+
+=Shipping the Exercise Torpedo.=—To be done in the same manner as
+prescribed for the Service Torpedo.
+
+The Exercise Torpedo may be used from either a boat‘s or ship‘s spar.
+It may be safely exploded at an immersion of 5 feet, and a horizontal
+distance of 20 feet.
+
+
+PREPARATION OF THE CONTACT TORPEDO.
+
+=Pattern D.—Plate V.=
+
+=To Convert a Service Torpedo into a Contact Torpedo.=—Attach a
+circuit-closer, Pattern B, to the frame on the lower head of the
+torpedo by screws through the lugs.
+
+=Testing the Circuit-Closer.=—Remove the water-cap and spherical
+rubber packing from the side of the circuit-closer; remove its
+screw-cover; take out the inner plunger. Remove the braid for a few
+inches from the longer leg (insulated double-conductor cable) at the
+outer end of the contact spar leading-wires, whipping the braid.
+Remove the rubber tape from the conductors, and pass them through the
+water-cap and packing and through the cylinder of the circuit-closer.
+Remove the insulation for one inch, brighten and lay up the naked wires
+and connect them to the binding-posts of the circuit-closer, taking
+care that the bare ends do not project far beyond the binding-posts.
+Seat the inner plunger, hauling on the wires at the same time, so as
+not to leave any slack wire in the cylinder. Set down the water-cap on
+the packing in the side of the circuit-closer. Replace the diaphragm,
+friction-plate and screw-cover. Remove the insulation for one inch
+from the shorter legs at the outer end of the leading-wires, and
+bend the naked wires together temporarily. Connect the inner ends of
+the leading-wires with the terminals of the testing-magneto, or of
+the C machine. Close the safety-break. Remove the safety-pin from
+the circuit-closer and press down the contact-arms. Under these
+circumstances a test with the testing-magneto, or with the C machine
+should show continuity. Release the contact-arms and put in the
+safety-pin. A test should now show no continuity. After this test the
+safety-pin must not be removed until just before submerging the torpedo
+prior to firing.
+
+_It is absolutely necessary that the circuit-closer be closed
+water-tight._
+
+=Priming the Contact Torpedo.=—Proceed as in priming the Service
+Torpedo.
+
+=Fuzing and Shipping the Contact Torpedo, and Shipping the Secondary
+Spar.=—Proceed as with the Service Torpedo, except that the contact
+spar leading-wires must be rove through the main spar, from aft
+forward, before fuzing the torpedo. The detonator must be spliced to
+the short legs of the leading-wires.
+
+=To Test the Circuit.=—The torpedo having been submerged, connect the
+inner ends of the leading-wires to the testing-magneto, or to the C
+machine. Close the safety-break and the hand-firing key and test. Under
+these circumstances continuity should be found.
+
+=To Fire at Will.=—Connect to the firing-battery, close the
+safety-break and, at the desired moment, close the hand-firing key.
+
+=To Fire on Contact.=—Connect to the firing-battery. Close the
+safety-break. When contact is made the contact-arms will be forced in,
+and the torpedo will explode.
+
+=_Note._=—The safety-break should be habitually left open, being
+closed only just before it is desired to put the circuit in condition
+to fire by closing either one of the two remaining breaks—that in the
+hand-firing key, when firing at will, or that in the circuit-closer,
+when firing on contact.
+
+
+IMPROVISED TORPEDOES.
+
+Torpedoes may be readily improvised from kegs or casks pitched outside.
+The fuze should be put in place before filling with powder, in order
+that it may be near the center of the charge. The spar leading-wires
+pass out through the close fitting scores in the bung. The latter,
+after being secured in its place, should be pitched over thoroughly,
+and weight added to the whole, in order that it may be readily
+immersed. For exercise torpedoes, bottles, oil-cans, etc., may be used.
+
+An excellent composition for rendering the bung and the entrance of the
+leading-wires water-tight is made by melting together 8 parts of pitch,
+1 of beeswax and 1 of tallow. It is to be applied while fluid.
+
+In order to burn all of the powder in the torpedo, a spindle, to
+contain the fuze, should be made on board of wood, following the
+general form of spindle in a gunpowder torpedo, and using a wrapping of
+cotton cloth, bunting, or paper, to prevent the powder passing through
+the flame-holes and choking up the spindle.
+
+=Splicing on the Fuze.=—To splice the fuze to the spar leading-wires
+so arrange the length of wire that the fuze will be entered in the
+spindle, reaching well into the torpedo-case when the entrance for
+the wires is closed. The leading-wires must be stripped of covering
+exterior to the insulation, to a distance extending to just outside
+the entrance. At this point the outer wrapping on the wires should
+be secured by a good whipping. If the outer wrapping on the wire is
+admitted inside, it will, after a time, act so as to introduce water to
+the charge.
+
+To make the splices, strip the insulation from the leading-wires for
+about an inch, and brighten them. Brighten the fuze-legs and twist them
+around the leading-wires in a manner similar to that employed in the
+Service Torpedo, arranging the splices, however, so that they shall be
+at equal distances from the top of the fuze. Cut off extra ends and
+lay the splices in the scores of the fuze-plug; turn the insulator
+down over them, and secure it with the insulator fastener. (See sample
+splice in supply-box).
+
+
+USE OF THE PERMANENT WIRES AND ELECTRIC SWITCHES.
+
+=Connecting.= (_Plate IX._)—The connections with the firing-battery
+are as follows:—one wire from each switch is connected to one battery
+terminal, and the common-return wire, with the hand-firing key
+interposed, is connected to the other battery terminal.
+
+The connections with the firing-key of the A machine are as
+follows:—one wire from each switch is connected to one binding-post,
+marked T, of the firing-key, and the common-return wire is connected to
+the other binding-post of the firing-key, also marked T.
+
+When electric switches are used an intelligent and careful person must
+be stationed at each switch, the index of which must be kept pointing
+toward “Battery off; connection through,” except when it is desired
+to prepare the circuit for firing any torpedo, when the index must be
+turned so as to point toward the torpedo which is about to be fired.
+
+The circuit for firing any single torpedo may thus be arranged; or, by
+moving the index to point toward “Battery on both” the circuits will be
+prepared for firing the two attached to that switch.
+
+By a proper manipulation of the switches the circuits may be prepared
+so that any one, two, or three, or all four of the torpedoes may be
+fired simultaneously.
+
+It must be borne in mind, however, that the electric switch is only a
+commutator for establishing the paths of the currents and that it must
+not be used as a firing-key.
+
+
+
+
+CHAPTER III.
+
+ELECTRICAL APPARATUS.
+
+
+FIRING-BATTERIES.
+
+Voltaic batteries are supplied for firing torpedoes from ships and
+boats. A modification of the Le Clanché cell has been adopted and is
+now issued from the Torpedo Station. One ship‘s firing-battery of six
+cells is supplied to such ships as are fitted with spars. For use in
+boats and elsewhere, as may be necessary, two boat‘s firing-batteries
+of four cells each, with two spare cells for each battery, are
+supplied. When the guns are to be fired by electricity an additional
+firing-battery will be furnished for the purpose.
+
+=_Note._=—Ships having only one torpedo launch will be supplied with
+but one boat‘s battery.
+
+
+THE CELL.
+
+=Plate XIII.=
+
+The positive element is zinc in the shape of a cylinder open at both
+ends. Around the zinc is molded a covering of okonite, which forms the
+jar of the cell. A lug from the zinc cylinder projects up through the
+okonite covering and has soldered to it the brass negative terminal of
+the cell. The negative element is a thin plate of platinum enclosed in
+a cylindrical muslin bag filled with crushed carbon. The bottom of the
+bag is closed by a flat, circular piece of ebonite. The top of the bag
+is seized to a plug of ebonite, through which passes a platinum wire,
+soldered to the platinum plate and to the brass positive terminal in
+the top. The ebonite plug is scored to take a rubber cover, the outer
+edge of which fits in a groove cut around the inside of the okonite
+cylinder above the top of the zinc, preventing loss of the liquid by
+splashing, or by evaporation. A hole in the cover permits the entrance
+of air, which is necessary for the proper operation of the cell. A
+rubber ring around the lower end of the negative element prevents its
+contact with the zinc. The liquid is a nearly saturated solution of
+sal-ammoniac (ammonium chloride). This cell polarizes rapidly on a
+short-circuit, but recovers in a few hours if left on open circuit.
+
+
+FIRING-BATTERY FOR SHIPS.
+
+The ship‘s firing-battery consists of six cells inclosed in a box. The
+cells are joined up in series. The terminals are at one end of the box,
+on top, and are covered by a lid hinged to the cover of the box.
+
+
+FIRING-BATTERY FOR BOATS.
+
+This pattern is similar to the ship‘s battery, except that four cells
+only are inclosed in its box.
+
+
+BATTERY TESTER.
+
+=Plate XIV.=
+
+This consists of a small wooden case inclosing a resistance-coil and a
+fuze-bridge. One end of the coil is connected to a brass spring and the
+other to one end of the fuze-bridge; the other end of the fuze-bridge
+is connected to a brass contact-piece opposite a spring at the other
+end of the case. When the tester is laid over the terminals of the
+battery and pressed down, contact is made between the contact-piece
+and spring, and a circuit established through the resistance-coil and
+bridge. If the battery is in good condition the bridge will be seen to
+redden, through a glass plate in the top of the case. The resistance
+of the coil in the tester for the ship‘s battery is 6.5 ohms and in
+the tester for the boat‘s battery it is 4 ohms.
+
+Should the fine wire bridge accidentally be broken, the plug must be
+removed and a new one inserted. A number of plugs, with bridges, are
+supplied for this purpose.
+
+
+MANAGEMENT AND CARE OF FIRING-BATTERIES.
+
+=To Prepare the Liquid.=—Make a saturated solution of sal-ammoniac with
+rain or distilled water. The solution will be hastened by crushing the
+crystals of sal-ammoniac and heating the water. Allow the solution to
+cool and settle, and decant it carefully. Then add one-tenth its volume
+of distilled or rain water.
+
+One pound of sal-ammoniac to four pints of water will give the proper
+degree of saturation.
+
+=To Fill the Cells.=—Press down the edge of the rubber cover at one
+point and, by inserting a screw-driver at this point, pry up the cover,
+and lift its edge all around. Introduce the liquid through a glass
+funnel, being careful to spill none of it on the connections, and fill
+the jars to within half an inch of the top. After twenty-four hours
+replenish the liquid, filling the jars to the same point as before, and
+replace the rubber cover.
+
+The ship‘s battery should be kept in a locker provided for it on the
+berth-deck, and should be kept connected with the wires leading to the
+firing apparatus on the spar-deck.
+
+Neither the ship‘s nor the boat‘s firing-batteries are to be tested
+too frequently, nor must the duration of a test be longer than is
+necessary. The batteries, if kept stationary in a proper locker, need
+be tested but once weekly. The boat‘s battery must be tested before it
+is sent into the boat, and again after it is put in place in the boat.
+
+The liquid should last from six to twelve months, according to the work
+done by the battery. Should the battery fail to show the proper test,
+search for bad or corroded connections. Test each cell separately, by
+touching the legs of a fuze-bridge directly to the poles of the cell. A
+single cell should redden the fuze-bridge when no other resistance is
+interposed. Faulty cells must be taken out, emptied and supplied with
+fresh liquid.
+
+The batteries must be examined daily. The connections must be kept
+clean and free from salts and, to secure this, the liquid must not
+be allowed to come in contact with them. Corroded connections can be
+cleaned with emery cloth, or, if very badly corroded, they may be
+scraped with the back of a knife-blade.
+
+Boat‘s batteries must be habitually examined after use in boats and any
+liquid that may have splashed about them be carefully wiped off.
+
+It sometimes happens that, from long use and impoverishment of the
+liquid, crystals of zinc-ammonium-chloride form in the cell, attaching
+themselves to the muslin bag and to the zinc. Sometimes these crystals
+build across from the bag to the zinc and prevent the ready removal
+of the negative element. When this occurs no effort should be made
+to remove it by force, for such a proceeding is liable to brake the
+platinum wire, or tear the thin platinum plate. To remove the negative
+element, take off the rubber cover and pour out the liquid, which
+should not be used again. Fill the cell with warm water and allow it to
+stand, full of water, for several hours. The crystals are but slightly
+soluble, but prolonged soaking will detach them sufficiently to permit
+the removal of the negative element. When this can be done the crystals
+are to be carefully picked off the muslin and scraped off the zinc. If
+such crystals are found in a cell, at any time, they must at once be
+removed and the liquid renewed.
+
+These batteries require but little care, but this little they must
+have. Systematic attention to them will be well repaid by their good
+performance and their constant readiness for use.
+
+Before the firing-batteries are returned into store at the end of
+the cruise, or before transportation to distant points, the negative
+elements must be removed from the cells, thoroughly soaked in fresh
+water and dried. The jars must be washed out and drained and all metal
+parts wiped perfectly dry.
+
+
+HAND-FIRING KEY.
+
+=Pattern B.—Plate XV.=
+
+This consists of two pieces of hickory, shaped to fit the hand, and
+joined together at the smaller end. Each piece is fitted with a brass
+contact stud projecting from its inner face at a short distance
+from the larger end. The natural spring of the wood keeps the two
+parts separated and maintains, normally, a break between the studs.
+A hole, bored longitudinally in each part, permits the entrance of
+a leading-wire, the bared end of which is secured by a screw to the
+contact stud. A rubber cot is seized over the key to prevent the
+closing of the circuit by sea-water. A safety-pin, attached to the
+key by a laniard, is habitually kept between the two parts to prevent
+accidental closing.
+
+The hand-firing key, introduced in an electrical circuit, provides a
+break that can be closed at will.
+
+
+THE TESTING-MAGNETO.
+
+This is a small magneto-electric machine, sending alternating currents
+into the external circuit. The circuit from the magneto includes an
+electro-magnet with a vibrating armature.
+
+The magneto will actuate this armature vigorously as a sounder, or
+rattler, through about 1000 ohms resistance. It may be used for testing
+the continuity of torpedo and other circuits, or for testing the
+insulation of the permanent and other leading-wires.
+
+=For Testing Continuity.=—The poles of the magneto are connected with
+the ends of the circuit to be tested and the crank turned. If the
+armature rattles it indicates a continuous circuit. The failure of the
+armature to rattle will show a break in the circuit.
+
+=For Testing the Insulation of the Permanent Wires.=—Connect one pole
+of the magneto with the wire to be tested and the other pole to earth;
+or, if a cross with some other wire is suspected, the other pole is
+connected with that wire. If the armature rattles vigorously when the
+crank is turned, a leak of less than about 1000 ohms resistance is
+indicated; if not, the insulation resistance of the wire is about 1000
+ohms.
+
+=To Test the Insulation of a Leading-Wire.=—Attach one end of it to one
+pole of the magneto, the other pole of which is connected by a short
+length of wire to an earth-plate placed in a tub of sea-water. Keeping
+the two ends of the wire to be tested out and dry, pay it into the tub
+gradually, turning the crank of the magneto meanwhile. Should there be
+a fault in the insulation, its existance and locality will be indicated
+by rattling of the armature when it reaches the water.
+
+
+FARMER‘S DYNAMO-ELECTRIC MACHINE, PATTERN A, AND FIRING-KEY.
+
+=Plate XVI.=
+
+For a full description of the electric machine, see “A Lecture on
+Galvanic Batteries, Part III” published by the Bureau of Ordnance, 1875.
+
+In general, pattern A may be considered as having an electro-motive
+force of sixteen to eighteen volts and a resistance of five ohms and to
+be capable of firing from twenty to twenty-five detonators arranged in
+series, or five to six arranged in as many branch circuits, or a single
+detonator through 1½ miles of cable such as is now issued, or through
+twenty ohms resistance.
+
+It is unnecessary to give more than three or four turns of the crank
+in order to generate sufficient current to fire; but these revolutions
+must be with the sun and continuous up to and including the moment
+of firing. In general, as more work is required from the machine,
+greater speed and longer time will be necessary to get the machine
+up to its maximum power; this time, however, is very limited and
+the rapid turning of the crank for half a minute may be considered
+sufficient. With a single detonator in circuit and a moderate amount
+of leading-wire, one-quarter of a turn of the crank will usually be
+sufficient to fire.
+
+=Testing the Machine.=—To test the machine, connect the binding-screws
+by a piece of metal, ship the crank and turn it with the sun. If it
+turn hard the machine is in good order; if it turn as easily as before
+the binding-screws were connected the machine is out of order.
+
+In case the machine is out of order it should be removed from the outer
+case and the cause sought out and remedied. There are no delicate parts
+or mechanism and the machine may be examined without fear of injury.
+
+The only faults which have been observed are the collecting of dirt
+between the shells of the commutator and the commutator springs, want
+of contact between them and the collecting of metallic dust between the
+two shells of the commutator. Each of these faults may be remedied in
+a moment. It is proper to say that these faults have never occurred
+when the machines were turned by hand and seldom when turned by power
+at a high rate of speed.
+
+Some of the wire connections inside the machine might be severed by
+the breaking of a soldered joint, of which there are five. A fault of
+this kind would be readily found and easily remedied. In soldering
+electrical connections, resin, and not acid, should be used.
+
+The effect of any of these faults is to cause a break in the continuity
+of the electrical circuit of the machine. This circuit is as follows:
+starting from one binding-screw, a wire leads to the field-of-force
+coils, or electro-magnet coils, traverses them and passes to one of the
+commutator springs; thence to one shell of the commutator; thence to
+the coil around the armature, through this coil to the other shell of
+the commutator; thence to the other commutator spring and, by a wire,
+to the second binding-screw, thus forming a complete circuit, when
+the binding-screws are joined together. If they are left unconnected,
+there is no closed circuit, no current is generated and the armature,
+therefore, turns easily. When the circuit is closed by connecting the
+terminals by a conductor of not too great resistance, the current
+generated excites the electro-magnets and this leads, in turn, to the
+generation of a stronger current until a maximum is reached depending
+on the resistance of the circuit and the speed with which the crank
+is turned. The electrical energy thus developed when the circuit is
+closed requires, of course, that extra work should be done to turn the
+crank. When the circuit is broken, inside or outside of the machine,
+it is necessary to overcome only the friction of the machine and the
+armature, therefore, turns easily.
+
+=The Purpose of the Firing-Key.= (_Plate XVI._)—The full power of the
+electro-magnets of the D. E. machine will be reached soonest and will
+be greatest when the two binding-screws are joined by a piece of metal
+of practically no resistance as, for instance, a short wire. If this
+short-circuit is kept closed until the moment of firing and is at that,
+moment replaced by the circuit containing the detonator, we will have
+the machine working with its magnets fully excited in the circuit in
+which useful work is to be done. In order to accomplish this change of
+circuit, without allowing the magnetism of the machine to fall, the
+second circuit must be completed before the first is broken. If we had
+no more convenient method we could take advantage of this property
+of the machine by connecting the two ends of the fuze-circuit to the
+two binding-screws of the machine, and laying a piece of metal across
+the two binding-screws. When the crank is turned a strong current is
+generated, the magnets reach their full strength and, on removing the
+piece of metal, the machine is thrown upon the fuze-circuit with its
+magnets strongly excited, generating sufficient current to fire the
+detonator.
+
+The firing-key furnishes a convenient method for making this change of
+circuit and also a means for testing the continuity of the fuze-circuit
+at any time before firing. When the firing-key is connected to the
+machine by wires between the binding-screws of the latter and those
+marked B, B, of the former and the binding-screws, marked T, T, of the
+former, are joined by a wire, there are three circuits which may be
+closed or broken by manipulation of the keys T and F of the firing-key.
+(_Plate XVII._)
+
+=The Short-Circuit.=—The current follows the path shown in Fig. 1.
+
+=The Test-Circuit.=—When the key T is pressed, the short-circuit is
+broken and the current follows the path shown in Fig. 2.
+
+=The Firing-Circuit.=—When the keys F and T are pressed, the current
+follows the path shown in Fig. 3.
+
+=To Test the Firing-Key.=—Connect as above and place the firing-key
+about ten or twelve feet from the machine, and so that the
+compass-needle points in the direction of the length of the box; ship
+the crank and turn it rapidly; if it turn hard the short-circuit is in
+good condition; then press the key T; if the crank turn easily and the
+compass-needle be deflected, the test-circuit is complete; then press
+the key F (the key T being already down); if the crank turn hard and
+the needle be no longer deflected, the firing-circuit is complete.
+
+
+FARMER‘S DYNAMO-ELECTRIC MACHINE.
+
+=Pattern C.—Plate XVI.=
+
+This machine, intended for use in boats, has less power than the large
+machine, and may generally be considered as having an electro-motive
+force of eight volts, and a resistance of four ohms, and to be capable
+of firing eight to ten detonators in series, or two to three arranged
+in as many branches, or a single detonator through 1500 feet of such
+cable as is now issued.
+
+This pattern combines within itself the firing and testing
+apparatus,—that is, the firing-key is permanently connected to the
+machine and the binding-screws of the C machine occupy a position
+analogous to that of the binding-screws T, T, of the firing-key.
+
+=To Test the Machine.=—Ship the crank and turn it rapidly with the
+sun; if it turn somewhat hard the short-circuit is complete; press the
+key T; the crank should turn with ease; connect the binding-screws by
+a short wire; turn the crank as before and press the key T; if the
+crank turn easier and a small bell be heard to strike inside, the
+test-circuit is complete. Continue turning the crank, press the key F
+and then the key T; if it continue to turn somewhat hard, and the bell
+does not sound, the firing-circuit is complete. The difference of force
+necessary to turn the crank during the several tests is not so apparent
+as with the larger machine. If any of the tests fail the machine
+should be taken from its case and the fault treated as with the larger
+machines.
+
+
+WIRES.
+
+=Insulation.=—Insulation is for the purpose of confining the electric
+current to the path we wish it to take and should be carefully looked
+after at all points not covered by the rubber or other permanent
+insulating matter. Faults in the insulation of the wires leading from
+the testing or firing apparatus to the torpedo may be so situated as to
+cause, in the former case, false tests and, in the latter, a sufficient
+weakening of the current through the detonator to prevent its firing;
+or, they may be so situated as to cause accidental explosion of the
+torpedo. The insulation of the wires, as well as that of the testing or
+firing apparatus, must therefore be carefully preserved.
+
+In order to preserve good insulation, all binding-screws should be kept
+clean and dry. Rain water has little effect, but salt water is bad.
+Wires which make short angles should be protected from chafe and all
+splices should be very carefully insulated by rubber tubing.
+
+Particular care must be taken to prevent metallic contact of the two
+legs of the detonator. Any such contact at that point would not be
+detected by testing and would be fatal to success.
+
+=Splicing Wires.=—Remove the jute braiding and rubber tape from the
+two ends to be spliced for such a distance as to be clear of the rubber
+tubing used to insulate the splices and whip the braiding. Bare the
+conductors of the two wires for about an inch and a half, lay them up
+and brighten them. Slip the piece of rubber tubing over the end of one
+of the wires. Unite the wires by a square-knot or sheet-bend, soldering
+the splice if it is to be permanent. Slip the rubber tubing over the
+splice so that its ends will overlap the rubber insulation of the wires
+and pass a snug seizing around each end of it.
+
+If the splice is to be permanent a better junction may be made as
+follows: Prepare the wires as before, bend up slightly the two ends,
+lay them side by side, and bind them tightly together with a whipping
+of fine wire; then turn the ends back on the splice and solder the
+whole together. Another good joint may be made as follows: Prepare the
+wires, but allow a greater length; lay them together and twist each
+about the other at right angles and in opposite directions; then solder
+all together.
+
+In all cases trim the splices so that there shall be no projecting
+wires to cut through the insulation.
+
+=Continuity.=—It is possible that a wire may be cut or broken at some
+point where such cut or break cannot be seen. If there be any reason to
+suspect such a break, the continuity of that wire may be readily tested
+by connecting it to the testing-magneto, using leading-wires known to
+be good, and proceeding as in other testing.
+
+
+
+
+CHAPTER IV.
+
+GUN-COTTON.—HOW PACKED.—STOWAGE.—CARE.—INSPECTION AND DRYING.
+
+
+PACKING AND STOWAGE OF WET GUN-COTTON.
+
+Each Service Torpedo, completely filled with wet gun-cotton, is packed
+in a rough box for transportation and stowage. The Exercise Torpedoes,
+ten filled with wet gun-cotton and two empty, are packed six in a box.
+
+Each filled torpedo has attached to its case a tag on which is marked
+the gross weight of the torpedo in pounds and ounces, the initials of
+the Superintendent of the Gun-cotton Factory and the factory number of
+the charge from which the contained gun-cotton is taken.
+
+When received on board ship the cover on which the address is marked
+is to be reversed. The torpedoes are then stowed in the magazine in a
+manner similar to that now employed in stowing shells.
+
+
+MARKS ON BOXES.
+
+    +-----------------------+------------------------+
+    |  PAT. D. TORPEDO,     |  PAT. D. TORPEDOES,    |
+    |      SERVICE.         |       EXERCISE.        |
+    |                       |                        |
+    | = .... LBS. DRY G. C. |  = .... LBS. DRY G. C. |
+    |                       |                        |
+    |(_Factory No. of_      |  (_Factory No. of_     |
+    |     __Charge._)       |       _Charge._)       |
+    +-----------------------+------------------------+
+
+
+PACKING-AND STOWAGE OF DRY GUN-COTTON.
+
+The glass jars for dry primers, filled with dry gun-cotton, are put in
+wooden cases, painted white, fitted with sliding covers as described on
+p. 13. The cases are marked “DRY GUN-COTTON PRIMERS. NOT TO GO BELOW.”
+They are packed in a rough box for transportation.
+
+When received on board ship the cases containing the jars are placed
+in different parts of the ship, but are never to be stowed below the
+water-line.
+
+On account of insurance restrictions imposed on freight companies it is
+often impracticable to ship gun-cotton in its dry state. When this is
+the case the gun-cotton primers are issued wet and are packed in the
+spare exercise torpedo-cases from which, on receipt aboard ship, they
+are to be removed and dried and then stowed in the glass jars for dry
+primers.
+
+       *       *       *       *       *
+
+A Torpedo Outfit, consisting of 24 Service, Pattern D. Torpedoes, 12
+Exercise (10 filled, 2 empty), Pattern D. Torpedoes and 4 jars of dry
+gun-cotton for primers will contain, approximately, the following
+amount of gun-cotton:—
+
+
+WET GUN-COTTON.
+
+    24 Service Pattern D,} {1296 2-inch blocks; or 1200}
+      Torpedoes          }={  2-inch blocks and 384    }wet = 818.1 lbs.
+                         } {  ½-inch blocks            } dry.
+
+    12 Exercise (10 full,} {60 2-inch blocks; or 50    }
+      2 empty) Pattern D,}={  2-inch blocks and 40     }wet = 37.9 lbs.
+      Torpedoes          } {  ½-inch blocks            } dry.
+
+                         } {1356 2-inch blocks; or 1250}
+    Total wet gun-cotton }={  2-inch blocks and 424    }wet = 856 lbs.
+                         } {  ½-inch blocks            } dry.
+
+
+DRY PRIMERS.
+
+   6 each of {16 ½-inch blocks;} {96 ½-inch blocks;}dry = 15.2 lbs. dry.
+             {or 4 2-inch blocks }={or 24 2-inch blocks}
+                                                         -----
+   Total equivalent of dry gun-cotton in outfit          871.2 lbs. dry.
+
+The wet charge of a torpedo, Pattern D, is composed of blocks two
+inches thick. The primer charge is composed of blocks ½ inch thick, if
+there be any on hand; otherwise, of blocks 2 inches thick.
+
+The 2-inch block contains 10.1 oz. and the ½-inch block 2.5 + oz. of
+dry gun-cotton.
+
+
+CARE OF GUN-COTTON AND DETONATORS.
+
+=The Gun-Cotton Magazine= must not be located near the boilers or
+engines, nor where the temperature of the magazine will equal 105° F.
+for any great length of time. The magazine should be aired frequently.
+Avoid as much as possible exposing any box or case containing
+gun-cotton, dry or wet, to the direct rays of the sun for any length of
+time, as the temperature inside the box can, in this way, be raised to
+a point considerably above that of the open air and this temperature
+will be maintained for a considerable time after the exposure.
+
+The diurnal changes of temperature will not affect gun-cotton, wet or
+dry, provided that the cases or boxes containing the gun-cotton are not
+exposed to the sun.
+
+The detonating charges of dry gun-cotton are designated “primers,” and
+the fulminate of mercury igniter as the “detonator.”
+
+The primers of dry gun-cotton supplied to each ship are packed in glass
+jars with tight covers to exclude moisture. Strips of blue litmus-paper
+are placed between the blocks of dry gun-cotton.
+
+The glass jars will be kept in their wooden cases. The jars and cases
+are a part of the permanent outfit and must be cared for and returned.
+Dry gun-cotton is never to be stowed below the water-line, but it may
+be carried under any deck above the water-line, care being taken that
+the glass jars, in their wooden cases, are not within 10 feet of each
+other, nor in the vicinity of the galley or other fires, nor in the
+immediate vicinity of the guns of the battery.
+
+In removing from their cases the glass jars holding the dry gun-cotton
+never expose them to the sun, as the glass may act as a lens and cause
+the ignition of the gun-cotton.
+
+All other primers will be furnished wet, and packed in the torpedo
+cases.
+
+As the stock of dry primers becomes reduced, a suitable time and place
+will be selected for replenishing the stock, by drying, according to
+the rules for drying gun-cotton, the blocks removed from the torpedoes
+in priming them.
+
+The detonator has a charge of 35 grains of fulminate of mercury.
+Detonators are placed in circular wooden blocks, bored to hold eight
+each, each block being put in a tin box. These tin boxes should never
+be put below the water-line, but kept in a dry place on the upper
+decks, and not in the immediate vicinity of the galley or other fires,
+of the battery, or of other explosives. _All loaded detonators are
+painted red_, and the tin boxes containing them are also painted red
+and marked on top “DANGEROUS.” Great care should be taken to grasp the
+box by the bottom when lifting or carrying it for, if held by the top
+only, the bottom, with its block, may slip out.
+
+
+INSPECTION OF GUN-COTTON.
+
+    _Weekly—all dry gun-cotton._
+    _Monthly—all dry gun-cotton._
+    _Quarterly—all wet gun-cotton._
+
+
+INSPECTION OF DRY GUN-COTTON.
+
+=Weekly Inspection.=—_The dry gun-cotton primers must be inspected
+weekly._ This can be done without opening the jars, by observing the
+condition of the blocks and the strips of blue litmus-paper placed
+between them.
+
+In the event of any serious decomposition having taken place, the
+gun-cotton will be found more or less covered with pasty, yellow
+spots, the jar will be filled with brownish red, highly acid fumes
+and the litmus-paper will show a decided red color. In this event the
+gun-cotton may be thrown overboard, but even when in this extreme
+condition there appears to be little danger of immediate explosion
+and, if desired for use, this gun-cotton may be wet with the alkaline
+solution (p. 45), until it has increased 30% in weight, and used
+as wet gun-cotton. No serious risk will attend this operation. No
+gun-cotton should be thrown overboard except when a board of experts
+has pronounced it to be in the condition above described. This is
+essential, as considerable valuable gun-cotton has been condemned and
+destroyed and a sense of insecurity has arisen in consequence of errors
+in inspection.
+
+It frequently occurs that the blue litmus-paper becomes faded by
+exposure in the jars, but no danger is to be apprehended in consequence.
+
+If the litmus-paper has become reddened, but no fumes or pasty spots
+are observed, the blocks should be lifted out by the loose ends of the
+tape and placed on a perfectly clean, dry piece of blotting-paper. Then
+untie the tape and separate the blocks, being careful not to touch them
+with the fingers. (A perfectly clean, dry crash towel may be used in
+handling the blocks.) Remove the strips of litmus-paper, insert freshly
+moistened strips in their places and tie the tape as before. After an
+hour‘s interval examine the ends of the strips of litmus-paper. If
+they have become reddened, wet the blocks with the alkaline solution
+(p. 45), until they have increased 30% in weight and use them as wet
+gun-cotton.
+
+If the moistened litmus strips have not become reddened after one
+hour‘s exposure, replace the blocks in the jar, close it tight and
+replace it in its box.
+
+=Monthly Inspection.=—Even if no change is observed in the
+litmus-paper at the weekly inspections the test just described, with
+freshly moistened blue litmus-paper strips, is to be applied to all
+dry gun-cotton once each month and this constitutes the _monthly
+inspection_. If the test shows the gun-cotton to be acid, the
+gun-cotton should be wet with the alkaline solution (p. 45), until it
+has increased 30% in weight, and then used as wet gun-cotton.
+
+
+INSPECTION OF WET GUN-COTTON.
+
+=Quarterly Inspection.=—The wet gun-cotton is packed in the Service and
+Exercise cases and contains from 30% to 35% of water. The gross weight
+of gun-cotton and case is marked upon each case. These cases are to be
+separately weighed every three months and any loss in the gross weight
+made up by the addition of pure water poured through the filling-hole,
+which should then be carefully closed.
+
+
+PRECAUTIONS TO BE TAKEN IN INSPECTION.
+
+Do not handle the gun-cotton with the bare hand. Never touch
+litmus-paper with the bare hand. Blue litmus-paper may become reddened
+by the acid substances exuded from the skin. Litmus-paper should always
+be handled with the forceps provided in the Chemical Box.
+
+Always moisten the litmus-paper before making the test, using the
+distilled water provided in the Chemical Box. Hold the litmus-paper
+strip in the forceps, dip one of the glass rods, provided in the
+Chemical Box, in the bottle of distilled water and then apply the
+moist rod to the paper. The litmus-paper must be moist, only, and not
+reeking with water. Should the supply of water in the Chemical Box be
+exhausted, water distilled on board, or fresh rain water, may be used,
+provided it first be tested and found free from acid reaction.
+
+Make a comparative test to prove that there is, or is not, an acid
+reaction. As blue litmus-paper may sometimes become slightly reddened
+when moistened with distilled water only, a comparison should always be
+made by taking two pieces of fresh blue litmus-paper and moistening one
+with distilled water and the other with dilute vinegar.
+
+Always examine the test papers by white light. Litmus-paper will
+present a reddish appearance in any apartment that is shellacked or
+colored; the examination of test papers should therefore be made only
+in a light room or in the open air.
+
+Do not mistake iron rust for pasty yellow spots. Gun-cotton sometimes
+becomes rusted in the course of manufacture, or from the cases in which
+it is packed. The rust does no harm.
+
+Avoid unnecessary handling of the blocks, as they are apt to flake and
+crumble.
+
+
+ALKALINE SOLUTION.
+
+The alkaline solution referred to above is made by dissolving four
+ounces of dry carbonate of soda in one gallon of rain or distilled
+water. When it is found necessary to wet dry gun-cotton this solution
+may be poured into the jar holding the blocks.
+
+
+RULES FOR DRYING GUN-COTTON.
+
+Wet gun-cotton primers can be dried by any of the following methods:—
+
+    1. Exposure in a steam-drier.
+    2.    ”     to calcium chloride. (Ca Cl₂).
+    3.    ”     in a dry atmosphere.
+
+The quantity of dry gun-cotton primers that are furnished being very
+small, the stock should be replenished as fast as used by drying the
+wet blocks removed from the torpedoes in priming them.
+
+
+DRYING BY EXPOSURE IN A STEAM-DRIER.
+
+The steam-drier must be located above the water-line, remote from
+fires and lamps and where it will not be subject to disarrangement.
+Its supply of steam is to be derived from a suitable part of the
+steam-heating apparatus of the ship or from any other convenient source
+of low-pressure steam by piping fitted at the Navy Yard.
+
+The blocks to be dried are separately weighed, the weight of each
+marked on it with a soft lead-pencil (never putting labels of any kind
+on the gun-cotton) and then strung on the rods, with the iron washers
+strung between adjacent blocks, and placed in the baskets of the drier.
+The baskets are put in the drier, the door is closed, the thermometer
+put in place, steam is turned on and the ventilating openings are
+adjusted.
+
+The baskets, rods and washers must be kept free from dirt and oil.
+
+The temperature of the drying chamber must not exceed 100° F.
+
+After each day‘s heating carefully remove and weigh each block, re-mark
+it and proceed with the drying.
+
+This process should be continued until the blocks no longer lose
+weight, when all but a small percentage of moisture will have been
+expelled. It has been found by experiment, however, that gun-cotton
+containing as much as 13% of water can be relied on to detonate, the
+service fulminate of mercury detonator being used.
+
+When the drying is complete remove the blocks from the drier, place
+them, while still warm, in the glass jars, with strips of blue
+litmus-paper between them and close the jars tight. They will then be
+stowed and inspected as dry gun-cotton.
+
+If the process of drying is not continuous the blocks must be kept in a
+powder tank, closed tight, when the drier is not in operation.
+
+
+DRYING BY EXPOSURE TO CALCIUM CHLORIDE (Ca Cl₂).
+
+This method requires:—5 lbs. calcium chloride (Ca Cl₂), 1 empty powder
+tank and 3 baking pans.
+
+The calcium chloride (Ca Cl₂) is cheap and can readily be obtained
+from any dealer in chemicals; it must not be confounded with chloride
+of lime or bleaching powder (CaO₂Cl₃). The latter has a strong odor of
+chlorine and, if used instead of the calcium chloride (Ca Cl₂), might
+cause decomposition of gun-cotton. The former is odorless and has no
+bleaching properties. To distinguish whether the substance has any
+bleaching properties, stir a small portion in an equal volume of water
+and immerse a piece of blue litmus-paper in the mixture. If the color
+disappears from the paper when dry (turning white), the substance is
+chloride of lime or bleaching powder (CaO₂Cl₂) and must not be used.
+
+The powder tank can be readily procured on board ship; care must be
+taken that it closes easily and air-tight.
+
+The baking pans should be of such a size that three of them will cover
+the bottom of the tank when placed alongside of each other; made of
+stout tin, free from solder, and 5 to 6 inches deep.
+
+Divide the calcium chloride between the three pans and place these
+pans, which must be clean and free from oil or grease, in the oven of
+the galley and allow them to remain there until all traces of moisture
+disappears. Stir the calcium chloride occasionally with a clean metal
+rod to expose the lower particles. Break it into pieces the size of a
+pigeon‘s egg. When all traces of moisture have disappeared remove the
+pans to a dry place and allow them to cool. The calcium chloride must
+not be put in the tank, nor the gun-cotton exposed to it, while warm.
+Place the tank in some suitable location where it will not be disturbed
+and, when the calcium chloride is cooled, place the pans in the bottom
+of the tank and lay over them a copper sieve, tinned copper wire being
+the best. Then place the blocks to be dried on the sieve and close the
+tank. Open the tank every 3 or 4 days, weigh the blocks, marking the
+weight and date with a soft lead-pencil on them and dry the calcium
+chloride as before. Continue this until the blocks have ceased to lose
+weight. While the calcium chloride is drying, the blocks are to be kept
+in the tank, which must be closed to exclude the moisture in the air.
+When they have ceased to lose weight stow them in the glass jars for
+dry gun-cotton primers, taking care to lay between them strips of blue
+litmus-paper, and treat them according to the rules laid down for dry
+gun-cotton.
+
+This operation is independent of the condition of the atmosphere and
+only requires the care mentioned.
+
+
+DRYING BY EXPOSURE IN A DRY ATMOSPHERE.
+
+String the blocks to be dried on a wood, brass or copper rod or pipe,
+which must be free from dirt and oil, or place them on a shelf made
+of wire netting, separating the blocks from each other to expose all
+surfaces freely to the air; suspend the rod or shelf in some suitable
+place not in the vicinity of the galley or other fires, where the
+blocks will be freely exposed to the air, and be under cover.
+
+Expose the blocks only when the atmosphere is dry; at all other times
+keep them in an empty powder tank, in the immediate vicinity of the
+place selected for drying, kept closed to exclude moisture. Weigh
+the blocks every two days, noting the date and weight with a soft
+lead-pencil on them. Continue the drying until the blocks show no
+loss of weight for two consecutive weighings; then place them in the
+glass jars, with strips of blue litmus-paper between, and treat them
+according to the rules given for dry gun-cotton primers.
+
+This plan can only be carried out in dry climates.
+
+Avoid unnecessary handling of the blocks, as they are apt to flake and
+crumble.
+
+
+MISCELLANEOUS DATA.
+
+Dimensions of gun-cotton blocks
+
+    length   2.9 inches.
+    width    2.9   ”
+    height { 2.0   ”    for full sized blocks,
+           { 0.5   ”    for primer blocks.
+
+Diameter of detonator hole = ⁷/₁₆ inch.
+
+Pressure applied to blocks in the final press = 6800 lbs. per square
+inch.
+
+Average gravimetric density of compressed dry gun-cotton = 1.287.
+
+Average weight of one cubic inch of compressed dry gun-cotton = 325
+grains, = 0.743 oz.
+
+Weight of water added to each pound of dry gun-cotton when issued to
+the service as wet gun-cotton (approximately 35%) = 0.35 lb. = 5.6 oz.
+
+
+
+
+APPENDIX.
+
+
+    DUTIES OF THE INSPECTOR OF ORDNANCE.—LIST
+        OF ARTICLES IN OUTFIT, WEIGHTS AND
+                 STOWAGE SPACE.
+
+    DUTIES OF THE INSPECTOR OF ORDNANCE AT THE NAVY
+       YARD IN CONNECTION WITH THE TORPEDO
+                OUTFIT OF A SHIP.
+
+GUN-COTTON MAGAZINE.
+
+He will carefully inspect the gun-cotton magazine, satisfy himself
+that it is constructed in accordance with the Ordnance Instructions
+concerning shell-rooms, and the directions given on pages 40 and 41
+Spar-Torpedo Instructions, that it is of sufficient size to stow the
+portion of the torpedo outfit defined in the “Table showing Weight,
+Space and Place of Stowage of Articles in Spar-Torpedo Outfit” and will
+prepare a plan of stowage.
+
+TORPEDO STOREROOM.
+
+He will carefully inspect the torpedo store-room, satisfy himself
+that it is in a proper position with regard to battery and boilers,
+that it is not exposed to undue changes of temperature, or to
+accidental admission of water, and that it is of sufficient capacity
+and conveniently arranged to stow the portion of the outfit defined
+in “Table showing Weight, Space and Place of Stowage of Articles in
+Spar-Torpedo Outfit.”
+
+BATTERY LOCKER.
+
+He will carefully inspect the battery locker and see that it is in a
+proper position with regard to the great-gun battery and the boilers.
+It should, preferably, be in a good light.
+
+SHIP‘S SPARS AND FITTINGS.
+
+He will, while the ship‘s spars and fittings are being made and
+when they are in place, inspect them carefully, satisfy himself
+that the spar-bands are properly spaced and in line to receive the
+secondary spar and report to the Bureau the position and class of the
+heel fittings and the leads of topping-lifts and guys, with his opinion
+of their efficiency and convenience.
+
+PERMANENT WIRES.
+
+He will ascertain what firing apparatus the Bureau intends to place on
+board and make a requisition for the necessary wire and terminals.
+
+Upon the receipt of these articles he will locate the firing apparatus
+and prepare and place the permanent wires and terminals.
+
+He will cause a plan showing the lead of the different wires to be
+made, and will send copies to the Bureau and to the Torpedo Station,
+and will furnish one to the commanding officer of the vessel.
+
+No fixed rules can be given for leading permanent wires. The general
+method of leading the upper-deck wires, manner of securing to terminals
+and precautions to be observed, are given on pages 14 and 15. Permanent
+wires should also be led from the battery to the firing-point on the
+bridge or elsewhere. In case of electrical gun-circuits being desired,
+special directions or plans will be issued by the Bureau of Ordnance.
+
+    LIST OF ARTICLES IN SPAR-TORPEDO OUTFIT
+      SUPPLIED FROM THE TORPEDO STATION.
+
+The Spar-Torpedo Outfit for ships having one torpedo boat comprises the
+articles given in the list. Ships having two or more torpedo boats will
+have the articles in the Boat‘s Outfit, necessary to the simultaneous
+use of all the boats, increased proportionally.
+
+              Ship‘s
+     Boat‘s    and
+     Outfit.  Boat‘s
+              Outfit.               BOX 1.
+                1     Farmer‘s D. E. machine, Pattern A, containing:—
+                1     Firing-key.
+                2     Machine connecting-wires (12 feet long).
+                1     Crank.
+
+                                    BOX 2.
+      1         1     Reel box, containing:—
+    300       300     Feet double-conductor insulated cable.
+      1         1     Crank.
+
+                                    BOX 3.
+      1         1     Supply-box, containing:—
+      1         1     Monkey wrench.
+      3         3     Open-end wrenches.—One end fits the screw-cover
+                         of the torpedo-case; the other, the screw-bolts
+                         that secure the spindle.
+      1         1     Rectifier,—a wooden rod, marked in inches, for
+                         lining the blocks in the primer-case.
+      6        12     Pieces of emery cloth,—for brightening wires and
+                         removing rust.
+      1         2     Pairs of cutting plyers,—for general use in
+                         cutting and working wires.
+      1         2     Pieces of okonite tape,—for insulating naked
+                         wires when not exposed to water.
+      2         2     Earth-plates,—copper plates (coated with tin to
+                         prevent rust).
+     12        24     Pieces of rubber tubing,—for insulating splices.
+      1         1     Sample splice,—for instruction.
+      1         2     Spools of hemp twine,—for securing rubber tubing.
+      1         2     Knives,—for cleaning wires and for general use.
+      1         1     Screw-driver,—for general use.
+      6        12     Dummy detonators (painted white),—for instruction.
+      1         1     Sample detonator splice,—for instruction.
+      1         1     Dummy gunpowder fuze,—for instruction.
+     24        36     Spherical rubber packings.
+     36        36     Paper fasteners.
+      2         2     Safety-pins for circuit-closer (spare).
+      1         1     Spring for circuit-closer (spare).
+      1         1     ⅜ by 16 screw-tap,—to cut a thread for
+                          spar screws.
+     12        12     Screws for boat‘s steel spars,—to secure the two
+                          parts of a boat spar.
+      4         4     Reeving-lines,—for reeving leading-wires through
+                          the boat‘s spars.
+      2         2     Reeving-line weights,—to reeve the reeving-lines
+                          through the boat‘s spars.
+
+                                    BOX 4.
+                1     Wire-box, ship‘s, containing:—
+                4     Spar leading-wires.
+                2     Machine connecting wires-(12 feet long, spare).
+
+                                    BOX 5.
+                4     Spar-bands with key-ways.
+                4         ”      (ordinary).
+               24     Wood screws.
+
+                                    BOX 6.
+      4         8     Tin boxes, containing:—
+      4         8     Detonator-blocks.
+     32        64     Detonators.
+
+                                    BOX 7.
+     32        32     Gunpowder igniters.
+     18        18         ”     fuzes.
+
+                                    BOX 8.
+      2         4     Glass jars with corks, containing:—
+     12        24     Blocks dry gun-cotton.
+
+                                   BOX 9.
+                1     Testing and firing plate
+                         (when specially ordered).
+
+                               BOXES 10 AND 11.
+               12     Secondary spars, ship‘s.
+               12     Keys for same.
+
+                                BOXES 12 AND 13.
+     12        12     Secondary spars, boat‘s.
+     12        12     Toggles for same.
+
+                                    BOX 14.
+      1         1     Farmer‘s D. E. machine, Pattern C, containing:—
+      2         2     Machine connecting-wires (12 feet long).
+      1         1     Crank.
+
+                                   BOX 15.
+      1         1     Wire-box, boat‘s, containing:—
+      4         4     Spar leading-wires.
+      2         2     Machine-connecting wires (12 feet long, spare).
+      4         4     Secondary spar caps.
+      4         4     Rivets for same.
+      4         4     Secondary spar butts.
+      4         4     Rivets for same.
+
+                                   BOX 16.
+      1         1     Chemical box, containing:—
+      2         2     Pair forceps.
+      2         2      ”   scissors.
+      2         2     Bottles distilled water.
+      2         2        ”    for litmus-paper.
+      ½         ½     Quire litmus-paper.
+      1         1     Tin cylinder for same.
+      2         2     Pounds carbonate of soda (dry).
+      1         1     Piece boiled tape.
+      2         2     Glass rods.
+
+                                   BOX 17.
+      2         2     Spar clamps.
+      1         1     Set of boat-fittings, Pattern B, as follows:—
+      2         2     Heel-rests.
+      2         2     Hinge-plates.
+      2         2     ⅝ bolts with nuts,—for securing heel-rests to
+                          hinge-plates.
+      2         2     Swivel-crutches,—each with a hinged top and two
+                          rollers, secured together by studs, rivets
+                          and pins.
+      2         2     Bearings secured to crutches with bolts and
+                          washers.
+      1         1     Cross-beam with two bearings riveted on.
+      2         2     Hoods, (right and left),—each fitted with two
+                          bolts for securing to the cross-beam.
+      2         2     Securing rods,—for securing elevating-arms to
+                          cross-beam.
+      2         2     Elevating-arms with cog-wheels attached.
+      2         2     Plate washers,—for holding elevating-arms on
+                          cross-beams.
+      2         2     Nuts on ends of securing rods,—to hold washers
+                          in place.
+      2         2     Guide rings,—each fitted with a roller secured
+                          by studs and split pins.
+      2         2     Screw-nuts,—each fitted with a lock-screw,
+                          to secure guide rings to elevating-arms.
+      2         2     Worm shafts,—each in two parts, joined by
+                          a hook-coupling.
+      2         2     Elevating-wheels,—with pins for securing same
+                          to worm shafts.
+      2         2     Clutches, consisting of the following parts:—
+      2         2     Bearings.
+      2         2     Sleeves,—with trunnions and lugs.
+      2         2     Yoke-links.
+      2         2     Detaching-levers,—each with transverse roller
+                          attached.
+      2         2     Pins,—for locking detaching-levers.
+      4         4     Bolts with split pins,—for securing parts of
+                          clutch together.
+     16        16     ⅝ bolts,—for securing hinge-plates, swivel-crutch
+                          bearings and clutch-bearings to boat.[1]
+     16        16     ⅝ phosphor-bronze nuts for same.
+      4         4     ¾ bolts,—for securing cross-beam bearings to
+                          deck.[2]
+      4         4     ¾ phosphor-bronze nuts for same.
+
+                                    BOX 18.
+      1         1     Testing magneto.
+
+                          BOXES 19 TO 22. (_Both inclusive_).
+      2         2     Boat spars.
+      2         2     Canvas bags for same.
+
+                          BOXES 23 TO 46. (_Both inclusive_).
+     12        24    Service Torpedoes, Pattern D.
+
+                                BOXES 47 AND 48.
+
+                                BOXES 49 AND 50.
+     12        12    Exercise Torpedoes, Pattern D,
+                         (two of which are empty).
+
+                                BOXES 51 AND 52.
+
+                                    BOX 53.
+     12        24     Service Torpedo spindles.
+     12        12     Exercise   ”       ”
+     24        36     Torpedo pins.
+      4         8        ”     ”   (spare).
+
+                                    BOX 54.
+                1     Ship‘s firing-battery.
+                1     Battery tester (6.5 ohms).
+      1         1     Boat‘s firing-battery.
+      2         2     Spare cells for same.
+      1         1     Battery tester (4 ohms).
+      1         2     Hand-firing keys.
+      3         5     Pounds sal-ammoniac.
+     12        12     Spare fuze bridges,—for testing batteries.
+
+                                    BOX 55.
+      1         1     Steam-drier.
+
+                                     BOX 56.
+      4         4     Circuit-closers,—for Contact Torpedo.
+      4         4     Spherical rubber packings for same.
+      4         4     Rubber diaphragms for same.
+     16        16     Brass screws,—for attaching circuit-closer.
+
+                                    BOX 57.
+      1         1     Contact spar leading-wires.
+      2         2     Rubber diaphragms (spare).
+     12        12       ”    washers,—for Exercise Torpedo (spare).
+     12        24       ”       ”    —for Service Torpedo (spare).
+      4         8     Spherical rubber packings (spare).
+                      In addition to the above, if no testing and
+                          firing-plate is furnished,
+                2     Electric switches.
+
+[1] =_Note._=—These bolts are supplied at the Navy Yard where the boats
+are fitted.
+
+[2] =_Note._=—These bolts are supplied at the Navy Yard where the boats
+are fitted.
+
+Two Copies of the Torpedo Instructions, corrected to date of issue,
+will be furnished to each vessel receiving a torpedo outfit.
+
+These copies will be sent by mail, simultaneously with the issue of
+the outfit, addressed to the Inspector of Ordnance at the Navy Yard at
+which the vessel is fitted out.
+
+       *       *       *       *       *
+
+This book is corrected to
+
+       *       *       *       *       *
+
+Terminals and insulated wire for permanent wires will be furnished as
+required.
+
+The Bureau of Ordnance will designate which of the following will be
+supplied:—
+
+             2    Electric switches.
+             1    Testing and firing-plate.
+
+                    SUPPLIED FROM NAVY YARD.
+                     Torpedo-spars for ship.
+                  Fittings for same.
+    16      16    ⅝ bolts,—for securing boat-fittings to boat.
+     4       4    ¾   ”      ”     ”      ”      ”     ”    ”
+
+    =_Note._=—Boxes 6, 7, 8, 23 to 46 inclusive, 49 and 50,
+       contain explosives, which must be stowed as directed in the
+       Instructions.
+    Boxes 8 and 16 contain glass and are to be handled with care.
+    Boxes 2, 4, 15 and 57 contain insulated wire and must be stowed in
+       a cool place to guard against deterioration of the insulation.
+    All other boxes must be stowed in a dry place and the contents kept
+       free from rust.
+
+    +---------------------------------------------------------------+
+    | Table Showing Weight, Space and Place of Stowage of Articles  |
+    |                       in Torpedo Outfit.                      |
+    +===========+========+==================+===========+===========+
+    |           |        |                  |           |           |
+    |           |Invoice |OUTSIDE DIMENSIONS|Approximate|Approximate|
+    | WHERE     | number | OF BOX IN INCHES |  cubical  |   gross   |
+    |  STOWED.  |of boxes+------------------+  space of | weight of |
+    |           |        |   L.    W.   D.  |  each box |  each box |
+    |           |        |                  |           |           |
+    +-----------+--------+------------------+-----------+-----------+
+    |           |        |                  |  Cu. ft.  |    Lbs.   |
+    |GUN-COTTON |23 to 26|  11.8  11.8 17.8 |    1.4    |    72.    |
+    | MAGAZINE. | 49, 50 |  13.8  12.9 17.  |    1.8    |    66.    |
+    +-----------+--------+------------------+-----------+-----------+
+    |           |    1   |  16.   13.5 20.5 |    2.6    |   146.    |
+    |           |    2   |  18.5  15.2 17.5 |    2.8    |    92.    |
+    |           |    3   |  20.   16.  10.5 |    1.9    |    48.    |
+    |           |    4   |  16.5  16.5 16.  |    2.5    |    67.    |
+    |           | 10, 11 |  98.5  14.   5.  |    4.     |   222.    |
+    |           | 12, 13 | 102.   21.   6.  |    7.4    |   230.    |
+    |           |   14   |  12.6  11.  16.5 |    1.3    |    54.    |
+    | TORPEDO   |   15   |  16.6 16.6  16.  |    2.6    |    68.    |
+    |STOREROOM. |   16   |  19.  11.6  12.6 |    1.6    |    30.    |
+    |           |   17   |  86.5 15.3  18.  |   13.8    |   400.    |
+    |           |   18   |   7.8  5.3   7.5 |     .2    |     9.    |
+    |           +--------+------------------+-----------+-----------+
+    |           |19 to 22| 219.   8.5   6.5 |    7.     |   205.    |
+    |           |        | 183.   8.5   6.5 |    5.8    |   170.    |
+    |           +--------+------------------+-----------+-----------+
+    |           |   53   |  19.8 11.6  15.1 |    2.     |   105.    |
+    |           |   55   |                  |           |           |
+    |           |   56   |  24.6 13.    8.2 |    1.5    |    43.    |
+    |           |   57   |  19.5 18.5   6.6 |    1.3    |    28.5   |
+    +-----------+--------+------------------+-----------+-----------+
+    | BATTERY   |   54   |  15.  10.5  11.5 |    1.     |    37.5   |
+    |  LOCKER.  |        |                  |           |           |
+    +-----------+--------+------------------+-----------+-----------+
+    |IN PLACE ON|    5   |  21.  16.5   7.5 |    1.5    |    80.    |
+    |     SPARS.|        |                  |           |           |
+    |” ” ” DECK.|    9   |  52.  18.5  18.5 |   10.4    |   155.    |
+    +-----------+--------+------------------+-----------+-----------+
+    |SEE        |    6   |   9.8  9.7   6.8 |     .4    |    10.    |
+    |REGULATIONS|    7   |  12.2 10.2   5.2 |     .4    |    11.    |
+    | FOR SAME. |    8   |   8.2 14.2  17.5 |    1.2    |    25.    |
+    +-----------+--------+------------------+-----------+-----------+
+
+    +===========+========================++=========================+
+    |           |      BOAT‘S OUTFIT     ||SHIP‘S AND BOAT‘S OUTFIT.|
+    |           |------+-------+---------++------+-------+----------+
+    | WHERE     |Number| Total |         ||      | Total |          |
+    |  STOWED.  |  of  |approx.|Aggregate||Number|approx.| Aggregate|
+    |           | boxes|cubical|  weight ||  of  |cubical|   Weight |
+    |           |      | space |         || Boxes| space |          |
+    +-----------+------+-------+---------++------+-------+----------+
+    |           |      |Cu. ft.|   Lbs.  ||      |Cu. ft.|   Lbs.   |
+    |GUN-COTTON |  12  |  16.8 |   864.  ||  24  | 33.6  |   1728.  |
+    | MAGAZINE. |   2  |   3.6 |   132.  ||   2  |  3.6  |    132.  |
+    +-----------+------+-------+---------++------+-------+----------+
+    |           |      |       |         ||   1  |  2.6  |    146.  |
+    |           |   1  |   2.8 |    92.  ||   1  |  2.8  |     92.  |
+    |           |   1  |   1.9 |    48.  ||   1  |  1.9  |     48.  |
+    |           |      |       |         ||   1  |  2.5  |     67.  |
+    |           |      |       |         ||   2  |  8.   |    444.  |
+    |           |   2  |  14.8 |   460.  ||   2  | 14.8  |    460.  |
+    |           |   1  |   1.3 |    54.  ||   1  |  1.3  |     54.  |
+    | TORPEDO   |   1  |   2.6 |    68.  ||   1  |  2.6  |     68.  |
+    |STOREROOM. |   1  |   1.6 |    30.  ||   1  |  1.6  |     30.  |
+    |           |   1  |  13.8 |   400.  ||   1  | 13.8  |    400.  |
+    |           |   1  |    .2 |     9.  ||   1  |   .2  |      9.  |
+    |           +------+-------+---------++------+-------+----------+
+    |           |   2  |  14.  |   410.  ||   2  | 14.   |    410.  |
+    |           |   2  |  11.6 |   340.  ||   2  | 11.6  |    340.  |
+    |           +------+-------+---------++------+-------+----------+
+    |           |   1  |   2.  |   105.  ||   1  |  4.   |    172.  |
+    |           |   1  |       |         ||   1  |       |          |
+    |           |   1  |   1.5 |    43.  ||   1  |  1.5  |     43.  |
+    |           |   1  |   1.3 |    28.5 ||   1  |  1.3  |     28.5 |
+    +-----------+------+-------+---------++------+-------+----------+
+    | BATTERY   |   1  |   1.  |    36.5 ||   1  |  1.9  |     70.5 |
+    |  LOCKER.  |      |       |         ||      |       |          |
+    +-----------+------+-------+---------++------+-------+----------+
+    |IN PLACE ON|      |       |         ||   1  |  1.5  |     80.  |
+    |     SPARS.|      |       |         ||      |       |          |
+    |” ” ” DECK.|      |       |         ||   1  | 10.4  |    155.  |
+    +-----------+------+-------+---------++------+-------+----------+
+    |SEE        |   1  |    .4 |    10.  ||   1  |   .7  |     20.  |
+    |REGULATIONS|   1  |    .4 |    11.  ||   1  |   .4  |     11.  |
+    | FOR SAME. |   1  |   1.2 |    25.  ||   1  |  2.2  |     49.  |
+    +-----------+------+-------+---------++------+-------+----------+
+
+
+
+
+INDEX.
+
+
+    After guy—ship‘s torpedo spar, 16
+    Alkaline solution, 45
+    Amount of water in wet gun-cotton, 44
+    Apparatus for drying gun-cotton, 13, 47, 48, 49
+    Articles for testing gun-cotton. (See Chemical box).
+       ” list of in outfit, 52
+       ” of torpedo outfit supplied at Navy Yard, 15, 56
+       ”  ”    ”      ”        ”    from Torpedo Station, 14, 52
+       ” spare, 1, 14
+
+    Bands, spar, 8, 53
+    Batteries, firing. (See Firing-batteries).
+    Battery-cell, description, 27
+       ” cells, spare, 27, 55
+       ” locker, 51
+       ” tester, 28, 55
+    Blocks, detonator, 11, 53
+       ” primer, dry, 12, 39, 40, 41, 49, 53
+    Boat, firing-batteries. (See Firing-batteries).
+      ” fittings, Pattern B, 8, 9, 10, 54, 55
+      ” spar. (See Spar).
+      ” to test the circuit from, 21
+      ” wire-box, 7, 54
+    Bow-fittings, 8, 54
+    Box, chemical, 13, 54
+     ” gunpowder fuzes and igniters, 12, 53
+     ” reel, 6, 52
+     ” stuffing, 3
+     ” supply, 8, 52
+     ” torpedo packing, 39
+     ” wire, boats, 7, 54
+     ”   ” ships, 6, 7, 53
+    Butts, secondary spar, 5, 54
+
+    Cable, insulated. (See Reel box).
+    Caps, secondary spar, 5, 54
+      ”       ”       ” rivets for, 54
+      ” water. (See Stuffing-boxes).
+    Care and management of firing-batteries, 29
+      ”  of gun-cotton and detonators, 41
+    Case, primer. (See Primer-case).
+    Cell, battery, 27
+    Cells, battery, spare, 27, 55
+    Charge, detonator, 10, 42
+    ” primer, dry. (See Primer charge).
+    Calcium, chloride. (See Chloride of calcium).
+    Chemical box, 13, 54
+    Chloride of calcium, 47
+       ”     ”    ” how distinguished from chloride of lime, 47
+       ”     ”    ” test of, for bleaching properties, 47
+       ”     ”    ” to be used instead of chloride of lime, 47
+       ”     ”  lime. (See Chloride of calcium).
+    Circuit-closer, Pattern B, description, 4
+       ”       ”       ”    ”  how attached, 4, 22
+       ”       ”       ”    ”  test, 22, 23
+       ”       ”       ”    ”  necessary to be water-tight, 23
+       ”       ”       ”    ”  number issued, 4, 56
+       ”       ”       ”    ”  safety-pin to be in before priming, 23
+       ”       ”       ”    ”  to be tested before priming, 23
+       ”       ”  safety-pins, spare, 53
+       ”       ”  spring, spare, 53
+       ”       ”  weight of, 5
+    Circuit testing, from ships, 20
+       ”    to test the, from boats, 21
+    Clamps, spar, 10, 54
+    Cloth, emery, 52
+    Commanding officer of vessel to be furnished with plan of wires, 52
+    Condition of firing-batteries, how to test, 28, 29
+    Connection to terminal, machine, or battery not to be made
+                                                         until, 20, 21
+    Contact, fire on, when using circuit-closer, Pattern B, 24
+       ”     spar leading-wires, Pattern B. (See Wires).
+       ”     torpedo. (See Torpedo).
+    Continuity of wires, testing, 32, 38
+    Crutch, swivel, 8, 54
+    Cutting plyers, 52
+
+    Depth. (See Immersion).
+    Detonator, 10, 41, 42, 53
+       ”       blocks, 10, 53
+       ”       bridge, resistance of, 11
+       ”       care of, 41
+       ”       charge, 11, 42
+       ”       dummy, 12, 53
+       ”       packing and stowage, 10, 42
+       ”       splice-sample, 53
+       ”       splicing on, 18
+       ”       testing, manner of, 17
+       ”        when tested, to be put in safe place, 17
+    Diaphragms, rubber, 56
+    Distance, proper, for contact torpedo before firing, 21
+       ”        ”      ”  exercise   ”      ”      ”     22
+       ”        ”      ”  service    ”      ”      ”     21
+    Drier, steam, 13, 46, 56
+    Dry primers. (See Primer).
+    Drying apparatus, gun-cotton, 13, 47, 48, 49
+      ”    gun-cotton, rules for, 45
+    Dummy detonators, 12, 53
+      ”   gunpowder fuze, 53
+    Dynamo-electric machine, pattern A, 32, 52
+       ”      ”        ”        ”    C, 36, 53
+
+    Earth-plates, 52
+    Electric switches, 15, 56
+       ”        ”      and permanent wires, use of, 25
+       ”        ”      not issued with permanent firing apparatus, 15
+       ”        ”       ”  to be used as firing keys, 26
+    Emery cloth, 52
+    Exercise torpedo. (See Torpedo).
+
+    Fasteners, paper, 53
+    Fire at will, contact torpedoes, 24
+      ”  on contact, contact torpedoes, 24
+      ”  torpedoes using A machine and firing-key, 21
+      ”      ”       ”   C    ”   , 21
+      ”      ”       ”   battery and hand-firing key, 21
+    Firing-batteries, 27
+      ”       ”       boats, 28, 55
+      ”       ”       how to test condition of, 28, 30
+      ”       ”       management and care of, 29
+      ”       ”       no connection to be made with until, 20, 21
+      ”       ”       not to be used to test the circuit, 21
+      ”       ”       number furnished, 27
+      ”       ”       ships, 28, 55
+    Firing-key, D. E. machine, pattern A, 34, 52
+      ”     ”   ”  ”     ”        ”    to test, 36
+    Fittings, boats. (See Boat-fittings).
+       ”      bow, 8
+       ”      heel, ship‘s torpedo spar, 16
+       ”        ”   ”         ”      ”   substitute for, 16
+       ” ship‘s spar, 16, 56
+    Forward guy, ship‘s torpedo spar, how fitted, 16
+    Fuze bridges, spare, 55
+     ”   gunpowder, dummy, 53
+     ”       ”      splicing on, 25
+    Fuzes, gunpowder, 12, 53
+    Fuzing torpedoes. (See Torpedo).
+
+    Glass jars for dry primers, 12, 41, 53
+    Gun-cotton, amount in torpedo outfit, 40
+     ”    ”       ” of water in when wet, 44
+     ”    ”     apparatus for drying, 13, 57, 48, 49
+     ”    ”     articles for testing. (See Chemical box).
+     ”    ”     care of, 41
+     ”    ”     dry, packing and stowage of, 39
+     ”    ”     inspection of, 42
+     ”    ”         ”       ”  precautions to be taken, 44
+     ”    ”     magazine, 41
+     ”    ”     miscellaneous data, 49
+     ”    ”     primers. (See Primers).
+     ”    ”     rules for drying, 45
+     ”    ”     test of. (See Inspection of gun-cotton).
+     ”    ”     removed in priming, where placed, 17, 22
+     ”    ”     wet, packing and stowage of, 39
+    Gunpowder fuze, dummy, 53
+        ”       ”   splicing on, 25
+        ”     fuzes, 12, 53
+        ”     igniters, 11, 53
+        ”     torpedoes, improvised, 24
+    Guy, after, ship‘s torpedo spar, 16
+     ”   forward, ”       ”      ”   how fitted, 16
+
+    Hand-firing key, 31, 55
+    Heel fittings, ship‘s torpedo spar, description, 16
+      ”     ”        ”       ”      ”   substitute for, 16
+    Hemp twine, 52
+    Horizontal distance. (See Distance).
+
+    Igniters, gunpowder, 12, 53
+    Immersion, proper for the exercise torpedo, 22
+        ”        ”     ”   ”  service torpedo, 21
+        ”        ”     ”   ”  contact torpedo, 21
+    Improvised torpedoes, gunpowder, 24
+    Inspection of gun-cotton, 42
+        ”       ”     ”       precautions to be taken, 44
+    Inspectors of ordnance at Navy Yard, duties of, 51
+    Instructions, Torpedo, copies of, 56
+    Insulated cable. (See Reel box).
+    Insulating splices, 38
+    Insulation of wires, 37
+        ”      ”    ”    not to be damaged, 37
+        ”      ”    ”    testing the, 32
+
+    Jars, glass, for dry primers, 12, 41, 53
+
+    Key for ship‘s secondary spar, 5, 53
+     ”  hand-firing, 31, 55
+    Knives, 3
+
+    Lead-covered wires, 14
+    Leading-wires. (See Wires).
+    Lift, topping, ship‘s torpedo spar, how fitted, 16
+    Lines, reeving, 20, 53
+      ”       ”     weights, 20, 53
+    Locker, battery, 51
+
+    Machine connecting wires, 6, 7, 52, 53, 54
+       ”    dynamo-electric, pattern A, 32, 52
+       ”       ”      ”         ”    C, 36,53
+       ”     no connection to be made with until torpedo is
+             immersed, 20, 21
+    Magazine, gun-cotton, 41
+    Magneto, testing, 31, 32, 55
+    Management and care of firing-batteries, 29
+    Monkey wrench, 52
+
+    Navy Yard, articles of torpedo outfit supplied at, 14, 56
+      ”    ”   Inspectors of ordnance at, duties of, 51
+    No connection to be made to terminal, battery, or machine
+                                                        until, 20, 21
+
+    Officer commanding vessel to be furnished with plan of wires, 52
+    Okonite tape, 18, 52
+    Open-end wrench, 52
+    Outfit, spar-torpedo, amount of gun-cotton in, 40
+      ”         ”         articles of, invoice number of boxes
+                                                    containing, 57
+      ”         ”            ”     ”  list of, 52
+      ”         ”            ”     ” place of stowage, 57
+      ”         ”            ”     ” spaced occupied when boxed, 57
+      ”         ”            ”     ” supplied at Navy Yards, 14, 56
+      ”         ”            ”     ” from Torpedo Station, 48
+      ”         ”            ”     ” weight of when boxed, 57
+      ”         ”         how designated, 1
+      ”         ”         includes, 1
+
+    Packing, spherical rubber, 3, 53, 56
+    Paper fasteners, 53
+    Permanent wires, 14, 56
+        ”       ”    plan to be furnished to, 52
+        ”       ”    use of, 25
+    Pins, safety, for circuit-closer, spare, 53
+      ”      ”     ”     ”      ”      to be in before priming, 23
+      ”   torpedo, 5, 55
+      ”      ”     spare, 55
+    Plate, testing and firing, 53, 56
+    Plates, earth, 52
+    Plyers, cutting, 52
+    Precautions to be taken in inspection of gun-cotton, 44
+    Preparation of contact torpedo, 22
+        ”        ” exercise ” pattern D, 22
+        ”        ” service  ”    ”    ”, 17
+    Primer blocks, 12, 39, 40, 41, 53
+       ”   case, description of, 2
+       ”   charge, 40, 41
+       ”   not to remain long in exercise torpedo, 22
+       ”   dry gun-cotton, care of, 41
+       ”     ”   ”   ”     how packed and stowed, 12, 39, 41
+       ”     ”   ”   ”     inspection of, 42
+       ”     ”   ”   ”     number furnished, 41, 42
+       ”     ”   ”   ”     precautions to be observed with, 42, 44
+       ”     ”   ”   ”     testing. (See Inspection of gun-cotton).
+       ”    wet  ”   ”     how packed, 39
+    Priming the exercise torpedo, 22
+       ”     ”  service torpedo, 17
+    Priming, wet gun-cotton removed in, where stowed, 17, 22
+
+    Rectifier, 19, 52
+    Reel box, 6, 52
+    Reeving-lines, 20, 53
+       ”    line weights, 20, 53
+    Resistance of detonator bridge, 11
+    Rivets for secondary spar butts, 54
+      ”     ”      ”       ”  caps, 54
+    Rubber diaphragms, 4, 56
+       ”   packing, spherical, 3, 53, 56
+       ”   tubing, 38, 52
+       ”   washers, 2, 56
+    Rules for drying gun-cotton, 45
+
+    Safety-break of contact spar leading-wires, 6
+       ”     ”   to be kept open until, 24
+    Sample splice, 52
+      ”      ”   detonator, 53
+    Safety-pin circuit-closer, spare, 53
+       ”    ”     ”       ”    to be in before priming, 23
+    Screw-driver, 52
+      ”   tap, 53
+    Screws for boat spar, pattern A, 53
+    Secondary spar. (See Spar).
+    Service torpedo. (See Torpedo).
+    Shipping contact torpedo, safety-pin to be in before, 23
+        ”    secondary spar. (See Spar).
+        ”    torpedo. (See Torpedo).
+    Ship‘s firing-batteries. (See Firing-batteries).
+      ”    testing circuit from, 20
+      ”    torpedo spar. (See Spar).
+      ”    wire-box, 6, 53
+    Solution, alkaline, 45
+    Spar-bands, 8, 53
+      ”  boat, pattern A, 10, 55
+      ”    ”      ”    ”  screws for, 53
+      ”    ”      ”    ”  to be taken apart when not in use, 10
+      ”  clamps, 10, 54
+      ”  leading-wires. (See Wires).
+      ”  secondary, butts, 5, 54
+      ”     ”         ”    rivets, 54
+      ”     ”       caps,  5, 54
+      ”     ”         ”    rivets, 54
+      ”     ”       keys,  5, 54
+      ”     ” pattern A, description, 5
+      ”     ”    ”    ”  difference between boats and ships, 5
+      ”     ”    ”    ”  how packed for boats, 5, 54
+      ”     ”    ”    ”   ”     ”    ”  ships, 5, 54
+      ”     ”    ”    ”  number supplied, 5
+      ”     ”  pattern A, shipping, 19
+      ”  secondary, pattern A, toggles, 5, 53
+      ”  ship‘s, description, 15
+      ”    ”     fittings, 16, 56
+      ”    ”     number supplied, 15
+      ”  torpedo. (See Torpedo).
+    Spare articles, 1, 14
+    Spherical rubber packing, 56
+    Spindle for torpedo. (See Torpedo).
+    Splice wire, insulating of, 38
+       ”    ”    sample, 52
+       ”   detonator, sample, 53
+       ”   towing strain on, how to prevent, 19
+    Splicing on detonator, 18
+       ”      ” gunpowder fuze, 25
+       ”     wires, 37
+    Spring for circuit-closer, spare, 53
+    Steam-drier, 13, 46, 56
+    Storeroom, torpedo, 51
+    Strain, towing on splices, how to prevent, 19
+    Stuffing-boxes, 3
+    Supply-box, 8, 52
+    Switches, electric. (See Electric switches).
+        ”        ”      and permanent wires, use of, 25
+    Swivel-crutch, 8, 54
+
+    Table showing weight, space, and place of stowage of articles, 57
+    Tape, okonite, 18, 52
+    Terminals, 15
+        ”      connection with not to be made until, 20
+    Test-circuit through circuit-closer, pattern B, how to, 22, 23
+      ”  condition of firing-batteries, how to, 28, 30
+    Tester, battery, 28, 55
+    Test, gun-cotton. (See Inspection of gun-cotton).
+    Testing and firing-plate, 53, 56
+       ”    circuit-closer, pattern B, 22
+       ”    circuit from boat, 21
+       ”       ”      ”  ship, 20
+       ”    continuity of wires, 32, 38
+       ”    detonator circuit in contact torpedoes, 24
+       ”        ”     manner of, 17
+       ”        ”     when, put in a safe place, 17
+       ”    gun-cotton, articles for. (See Chemical box).
+       ”    insulation of wires, 32
+       ”    magneto, 31, 32, 55
+    Toggles, secondary spar, 5, 53
+    Topping lift, ship‘s spar, 16
+    Torpedo, contact, circuit-closer to be tested before priming, 22
+       ”        ”     fuzing, 23
+       ”        ”     no connection to be made until, 21
+       ”        ”     preparation of, 22
+       ”        ”     priming, 23
+       ”        ”     proper distance and immersion, 21
+       ”        ”     shipping, 23
+       ”        ”     safety-pin to be in, 23
+       ”        ”     splicing on detonator for, 23
+       ”        ”     testing circuit, 24
+       ”        ”     to fire at will, 24
+       ”        ”      ”   ”  on contact, 24
+       ”        ”     spar leading-wires, pattern B, 7, 22, 23, 24
+       ”    exercise, pattern D, description, 2
+       ”        ”        ”    ”  fuzing, 22
+       ”        ”        ”    ”  necessary to be closed
+                                                 water-tight, 3, 22
+       ”        ”        ”    ”  no connection to be made until, 20, 21
+       ”        ”        ”    ”  number issued, 2, 40
+       ”        ”        ”    ”  outfit of, 40, 55
+       ”        ”        ”    ”  packed, 39
+       ”        ”        ”    ”  preparation of, 22
+       ”        ”        ”    ”  primer not to remain in long, 22
+       ”        ”        ”    ”  priming, 22
+       ”        ”        ”    ”  shipping, 22
+       ”        ”        ”    ”  spindle packed, 5, 55
+       ”        ”        ”    ”  splicing detonator on, 22
+       ”        ”        ”    ”  testing, 22
+       ”        ”        ”    ”  weight, empty, 3
+       ”        ”        ”    ”  of charge, 3
+       ”        ”        ”    ”  when issued filled with wet
+                                             gun-cotton, 3, 39, 44
+       ”        ”        proper distance and immersion, 22
+       ”   Instructions, copies of, 56
+       ”   outfit. (See Outfit).
+       ”   no connection to terminal, battery, or machine to be
+                                               made until, 20, 21
+       ”   packing boxes, 39
+       ”   pins. (See Pins).
+       ”   service and contact, proper distance and immersion, 21
+       ”      ”    pattern D, conversion of to contact torpedo, 2, 22
+       ”      ”       ”    ”  description, 1
+       ”      ”       ”    ”  firing, 21
+       ”      ”       ”    ”  fuzing, 19
+       ”      ”       ”    ”  necessary to be closed water-tight, 2
+       ”      ”       ”    ”  no connection to be made until, 20, 21
+       ”      ”       ”    ”  not advisable to prime long before
+                                 using, 17
+       ”      ”       ”    ”  number issued, 1, 40
+       ”      ”       ”    ”  outfit, 40, 55
+       ”      ”       ”    ”  preparation of, 17
+       ”      ”       ”    ”  primer-case, 2
+       ”      ”       ”    ”  priming, 17
+       ”      ”       ”    ”  shipping, 19
+       ”      ”       ”    ”  splicing detonator on, 18
+       ”      ”       ”    ”  spindle, 2, 55
+       ”      ”       ”    ”  testing, 20, 21
+       ”      ”       ”    ”  weight, empty, 2
+       ”      ”       ”    ”  of charge 2
+       ”      ”       ”    ”  when issued filled with wet
+                                              gun-cotton, 2, 39, 44
+       ”    spars, ship‘s, 15
+       ”      ”       ”  number of, 15
+    Torpedo Station, articles supplied from, 52
+       ”    store-room, 51
+    Torpedoes, firing, using A machine and firing-key, 21
+        ”        ”       ”   C    ”    21
+        ”        ”         ” battery and hand-firing key, 21
+        ”      gunpowder improvised, 24
+        ”      how named, 1
+        ”       ”  packed and marked, 39
+        ”       ”  to be stowed on board ship, 39
+        ”      intended use of, 1
+        ”      when received on board, what to do with, 39
+    Towing strain on splices, how to prevent, 19
+    Tubing, rubber, 38, 52
+    Twine, hemp, 52
+
+    Use of permanent wires and electrical switches, 25
+     ”   ” leading-wires with circuit-closer, pattern B, 22, 23, 24
+
+    Washers, rubber, 2, 56
+    Water, amount in wet gun-cotton, 44
+      ”    caps. (See Stuffing-Boxes).
+    Weights, reeving-line, 20, 53
+    Wet gun-cotton, amount of water in, 44
+     ”   ”     ”    packing and stowage of, 39
+     ”   ”     ”    removed in priming, where placed, 17, 22
+     ”  primers.    (See Primers).
+    Will, to fire at, contact torpedo, using circuit-closer,
+                                                  pattern B, 24
+    Wire-box, boat‘s, 7, 54
+      ”   ”   ship‘s, 6, 7, 53
+    Wire, continuity of, testing the, 32, 38
+      ”   insulation of, 37
+      ”        ”      ”  not to be damaged, 37
+      ”        ”      ”  testing the, 32
+      ”   splice, insulating, 38
+    Wires, contact spar leading, pattern B, 7, 22, 23, 24
+      ”    lead-covered, 14
+      ”    machine connecting, 6, 7, 52, 53, 54
+      ”    permanent. (See Permanent).
+      ”        ”       plan of, to be furnished to, 52
+      ”    spar leading, how marked, 7
+      ”      ”     ”     boats, 7
+      ”      ”     ”       ”    to be led through spar, 20
+    Wires, spar leading, never to be connected to terminals,
+                                  battery, or machine until, 20, 21
+      ”      ”      ”    ship‘s, 6, 54
+      ”      ”      ”      ”     to be stopped to spar, 19
+      ”    splicing, 37
+    Wrench, monkey, 52
+    Wrenches open-end, 52
+
+
+
+
+PLATES.
+
+                            =PLATE I.=
+
+                 SERVICE TORPEDO.—PATTERN D.
+
+    _A_ barrel.
+    _B_ lower head.
+    _C_ upper   ”
+    _g_, _h_ splices between leading-wires and detonator-wires.
+    _K_ handle.
+    _l_ lugs for handle.
+    _k_   ”   ”  spindle.
+    _i_, _i_ screw-holes for attaching circuit-closer.
+    _n_ screw-rib for screw-cover.
+    _r_ projection on handle shipping into spindle.
+    _t_ screw-bolts securing spindle to lugs.
+    _H_ spindle.
+    _L_ spar leading-wires.
+    _M_ water-cap.
+    _P_ primer-case.
+    _O_ screw-cover.
+    _w_ rubber washer.
+    _G_ spherical rubber packing.
+    _D_, _D_ dry gun-cotton primer.
+    _x_ detonator.
+    _Y_ wet charge.
+
+[Illustration: PLATE I.]
+
+                           =PLATE II.=
+
+                EXERCISE TORPEDO.—PATTERN D.
+
+    _c_ case.
+    _d_ lower loop.
+    _e_, _e_ loops for transportation thumb-screw and
+                       for spindle.
+    _f_ throw-back hinge with thumb-screw.
+    _H_ spindle.
+    _O_ cover.
+    _w_ rubber washer.
+    _M_ water-cap.
+    _G_ spherical rubber packing.
+    _Y_, _Y_, _Y_, _Y_ wet charge.
+    _D_, _D_, _D_, _D_ dry primer.
+    _x_ detonator.
+    _L_ spar leading-wires.
+    _g_, _h_ splices between leading-wires and
+                       detonator-wires.
+
+[Illustration: PLATE II.]
+
+                           =PLATE III.=
+
+        CIRCUIT-CLOSER.—PATTERN B.—CONTACT TORPEDO.
+
+    _A_ hollow brass casting.
+    _M_ water-cap.
+    _G_ spherical rubber packing.
+    _O_, _O_ feet for attaching circuit-closer to service
+                       torpedo, Pattern D.
+    _B_ inner brass plunger.
+    _C_ spiral spring.
+    _N_ ebonite collar.
+    _I_, _I_ binding-posts.
+    _E_ contact-springs.
+    _t_ screw-cover.
+    _s_, _s_ contact arms.
+    _K_ outer plunger.
+    _l_ safety-pin.
+    _V_ rubber diaphragm.
+    _k_ friction-plate.
+
+[Illustration: PLATE III.]
+
+[Illustration]
+
+                           =PLATE IV.=
+
+                           SECONDARY SPARS.
+
+                 FIG. 1, SHIP‘S.—PATTERN A.
+
+    _A_ main spar.
+    _B_ secondary spar.
+    _a_, _a_ spar-bands.
+    _b_ key-way.
+    _c_ key.
+    _l_ hole for torpedo-pin.
+    _m_ torpedo-pin.
+
+[Illustration: PLATE IV.]
+
+                 FIG. 2, BOAT‘S.—PATTERN A.
+
+    _R_ main spar.
+    _H_ secondary spar.
+    _i_ butt.
+    _k_ cap.
+    _g_ toggle.
+    _l_ hole for torpedo-pin.
+    _m_ torpedo-pin.
+
+[Illustration]
+
+                            =PLATE V.=
+
+           CONTACT SPAR LEADING-WIRES.—PATTERN B.
+
+    _B_ battery.
+    _C_ contact torpedo.
+    _x_ circuit-closer.
+    _D_ contact spar leading-wires.
+    _H_ hand-firing key.
+    _S_ safety-break.
+
+[Illustration: PLATE V.]
+
+                           =PLATE VI.=
+
+           SPAR-TORPEDO BOAT-FITTINGS.—PATTERN B.
+
+    _S_ heel-rest.
+    _H_ swivel-crutch.
+    _R_ cross-beam.
+    _D_     ”      bearing, riveted to cross-beam and bolted
+                        through rail.
+    _E_ elevating-arm.
+    _m_ plate washer.
+    _n_ nut on end of securing rod.
+    _G_ guide-ring.
+    _K_ gear on elevating-arm.
+    _M_ worm.
+    _N_ worm-shaft, forward length.
+    _O_   ”    ”    after      ”
+    _X_ hook-coupling.
+    _P_ elevating-wheel.
+    _Q_ clutch.
+    _L_ detaching-lever.
+    _T_ torpedo.
+    _A_ main spar.
+    _B_ secondary spar.
+
+[Illustration: PLATE VI.]
+
+[Illustration]
+
+                           =PLATE VII.=
+
+      JUNCTION OF TUBES FORMING BOAT‘S SPAR.—PATTERN A.
+
+    _A_ large tube.
+    _B_ small tube.
+    _c_, _c_ rings.
+    _d_ shoulder.
+    _e_ screw-holes.
+    _f_ feather.
+    _g_ score.
+
+[Illustration: PLATE VII.]
+
+[Illustration]
+
+                          =PLATE VIII.=
+
+                      FIG. 1, DETONATOR.
+
+    _A_ copper case.
+    _B_ plug.
+    _c_, _c_ detonator-legs.
+    _D_ bridge.
+    _F_ gun-cotton priming.
+    _H_ fulminate of mercury.
+
+                   FIG. 2, DETONATOR BLOCK.
+
+    _A_ block.
+    _B_   ”   cover.
+    _C_, _C_ detonators.
+    _D_, _D_ tin box.
+
+[Illustration: PLATE VIII.
+
+_Fig. 1._]
+
+[Illustration: _Fig. 2._]
+
+                           =PLATE IX.=
+
+                   FIG. 1, PERMANENT WIRES.
+
+    _A_, _A_ electric switches (on bulwarks under bridge).
+    _B_, _B_ forward terminals.
+    _C_, _C_ after       ”
+    _D_, _D_ forward permanent wires.
+    _E_, _E_ after       ”       ”
+    _G_, _G_ permanent wires leading from bridge to lower
+                       binding-posts of electric switches.
+    _H_, _H_ wires leading from bridge to common-return
+                       terminals, below switches.
+    _K_ terminal on bridge for wires _H_, _H_.
+    _L_, _L_ ”   ”    ”     ”    ”   _G_, _G_.
+    _X_ firing-battery connected to terminals on bridge.
+
+     FIG. 2, CONNECTIONS WITH FIRING-KEY OF “A” MACHINE.
+
+    _B_, _B_ terminals of firing-key.
+    _T_, _T_    ”      ”       ”
+    Key “_T_” test key.
+    Key “_F_” firing key.
+    _M_, _M_ wires to terminals _L_, _L_
+                                          on bridge. (Fig. 1.)
+    _N_ wire to terminal _K_ on bridge (common return).
+                                          (Fig. 1.)
+    _O_, _O_ machine-connecting wires.
+
+           FIG. 3, CONNECTIONS WITH FIRING-BATTERY.
+
+    _B_, _B_ terminals of battery.
+    _M_, _M_ wires to terminals _L_, _L_
+                                          on bridge. (Fig. 1.)
+    _N_ wire to terminal _K_ on bridge (common return).
+                                         (Fig. 1.)
+    _H_ hand-firing key.
+
+[Illustration: PLATE IX.
+
+_Fig. 2._]
+
+[Illustration: _Fig. 3._]
+
+[Illustration: _Fig. 1._]
+
+                            =PLATE X.=
+
+                   FIG. 1, ELECTRIC SWITCH.
+
+    _A_ permanent wire to forward torpedo.
+    _B_       ”    ”   ”  after      ”
+    _C_, _C_  ”    ”   common return.
+    _D_ wire to battery or firing-key of machine.
+    _E_ commutator of switch.
+
+[Illustration: PLATE X. _Fig. 1._]
+
+                      FIG. 2, TERMINAL.
+
+    _H_ binding-screw.
+    _I_ permanent wire.
+    _w_ wire temporarily connected.
+
+[Illustration: _Fig. 2._]
+
+                           =PLATE XI.=
+
+                HEEL FITTINGS FOR SHIP‘S SPAR.
+
+    _a_ ship‘s spar.
+    _b_ thrust-plate (30″ diameter).
+    _c_ eye-bolt through thrust-plate and ship‘s side.
+    _d_ heel-bolt.
+
+[Illustration: PLATE XI.
+
+_Fig. 2._]
+
+[Illustration: _Fig. 1._]
+
+                           =PLATE XII.=
+
+                    SHIP’S SPAR FITTINGS.
+
+    _a_ ship’s spar.
+    _b_ topping lift.
+    _c_ forward guy.
+    _d_ after    ”
+    _e_ span for topping lift (16′ long).
+    _f_  ”    ”  forward guy  (16′ long).
+    _x_, _x_, _x_, _x_ bands on spar (5′ apart).
+
+[Illustration: PLATE XII.]
+
+                          =PLATE XIII.=
+
+                        BATTERY CELL.
+
+    _a_ okonite jar.
+    _b_, _b_ zinc cylinder.
+    _c_ platinum plate.
+    _d_ muslin bag filled with crushed carbon.
+    _e_ ebonite disc.
+    _f_    ”    plug.
+    _g_ sal-ammoniac solution.
+    _h_ positive terminal.
+    _i_ negative    ”
+    _k_ rubber cover.
+    _r_ rubber ring.
+
+[Illustration: PLATE XIII.]
+
+    =PLATE XIV.=
+
+    BATTERY TESTER.
+
+    _a_, _a_ battery terminals.
+    _b_         ”    tester.
+    _c_ fuze-bridge in tester.
+
+[Illustration: PLATE XIV.]
+
+                           =PLATE XV.=
+
+             FIG. 1, HAND-FIRING KEY.—PATTERN B.
+
+    _a_, _a_ hickory pieces.
+    _c_, _c_ contact studs.
+    _L_, _L_ leading-wires.
+    _d_ rubber cot.
+    _e_ safety-pin with hole for laniard.
+    _f_ eye-bolt for laniard.
+
+     FIG. 2, DIAGRAM SHOWING HAND-FIRING KEY IN CIRCUIT.
+
+    _B_ battery.
+    _H_ hand-firing key.
+    _w_, _w_ leading-wires.
+
+[Illustration: PLATE XV.]
+
+                           =PLATE XVI.=
+
+        FIG. 1, “A” MACHINE AND FIRING-KEY CONNECTED.
+
+    _A_ “A” machine.
+    _C_ firing-key.
+    _B_, _B_ terminals of firing-key.
+    _T_, _T_     ”     ”      ”
+    Key “T” test key.
+     ”  “F” firing-key.
+    _O_ machine-connecting wires.
+    _w_, _w_ wires to torpedo.
+
+                FIG. 2, “C” MACHINE CONNECTED.
+
+    _D_ “C” machine.
+    _C_ firing-key (in the machine).
+    Key “T” test key.
+     ”  “F” firing-key.
+    _w_, _w_ wires to torpedo.
+
+[Illustration: PLATE XVI.]
+
+                           =PLATE XVII.=
+
+    FIG. 1, firing-key, short-circuit.
+     ”   2,       ”     testing circuit.
+     ”   3,       ”     firing-circuit.
+    _O_, _O_ machine-connecting wires.
+    _w_, _w_ wires to torpedo.
+    _B_, _B_ terminals of firing-key.
+    _T_, _T_     ”     ”        ”
+    Key “T” test key.
+    Key “F” firing-key.
+
+[Illustration: PLATE XVII.
+
+_Fig. 1._]
+
+[Illustration: _Fig. 2._]
+
+[Illustration: _Fig. 3._]
+
+      =PLATE XVIII.=
+
+    STEAM-DRIER.
+
+[Illustration: PLATE XVIII.
+
+_Fig. 1._]
+
+[Illustration: _Fig. 2._]
+
+
+
+
+*** END OF THE PROJECT GUTENBERG EBOOK 76987 ***