NRLF D71 OV/7 NOTES ON THE 3 INCH GUN MATERIEL AND FIELD ARTILLERY EQUIPMENT COMPILED FOR THE RESERVE OFFICERS' TRAINING CORPS OF YALE UNIVERSITY (Revised and Enlarged) BY LIEUT.-COL E. L GRUBER FIELD ARTILLERY, N. A. CONTENTS Pages Introduction : Object of Instruction 1 The Gun : Description ?, Weights & Dimensions 3 Nomenclature 3 The Breech Mechanism : Description 5 Nomenclature 5 The Gun Carriage : Description 6 Action of the mechanism 12 Weights & Dimensions 12 Nomenclature 12 The Limber : Description 14 Weights & Dimensions 16 Nomenclature 16 The Caisson : Description 16 Weights & Dimensions 19 Nomenclature 19 Dismounting & Assembling Parts of the Gun and Carriage 21 Sights & Observing Instruments : General Instructions 27 Care & Cleaning og Sights : Description 30 Line Sights P )0 Front & Rear Sights 30 Rear Sight, Nomenclature 30 Panoramic Sight, M '15 ;);> Range Quadrant 32 Field Adjustment, Sights and Quadrant 35 Observing Instruments : B. C. Telescope, Description & ifec,. ; ,\ :..>.. 36 Aiming Circle, Description & Use ".'./..'.... .* 40 Adjustment of B. C. Telescope and Aiming Cjrcle'A .;.,.,.:. ;.V,.\ ::*,;.":' .'.^"42 Range Finder, Description & Use 45 Adjustment of Range Finder 50 Field Glasses, Care & Use.. 52 THK GUN (Fig. 1) 6. The Gun with which the batteries of this organization are equip- ped, is known officially as the j-inch Field Gun, Model TQO$. This gun is a built-up construction of nickel steel and consists of a tube with a rifled bore, 3 inches in diameter, upon which are shrunk the jacket, locking hoop and front clip hoop. The jacket reinforces the rear half of the tube. The locking hoop serves to secure the jacket from any longi- tudinal movement to the rear. On the under side of the gun, extending the entire length of the jacket, locking hoop, and front clip, are formed two recoil guides or clips which fit over and secure the gun to the guide rails of the cradle. When the gun is fired, it glides along the guide rails. The dust guard covers that part of the guide rails between the locking hoop and the front clip. The rifling of the bore is right hand twist and starts with turns at the breech increasing to 1 turn in 25 calibers at 10 inches from the muzzle, then uniform to the muzzle. WEIGHTS AND DIMENSIONS 7. Weight of gun 788 Ibs. Calibre 3 inches Length about 7 feet Number of lands and grooves 24 Muzzle velocity 1700 ft. sec. Maximum pressure per sq. in 33,000 Ibs. Limit of depression (90 mils) 5 degrees Maximum elevation (265 mils) 15 degrees Maximum range, trail sunk, about 8,500 yds. Range at 15 elevation (265 mils) " 6,000 yds. I. Nomenclature of parts of Gun : Jacket. Front clip. Locking hoop. Muzzle. Tube. Dust guard. Bore. Recoil guides or clips. Rifling. Chamber. Lands. Recoil lug. Grooves. Line sight (front and rrar) Breech recess. Handy oilers. . W * <^to*fcJ ! THE BREECH MECHANISM (Fig. 2) 9. The breech-block is of the interrupted-screw type, and is provided with four threaded and four slotted sectors. The front end of the axial recess in the block is closed by a bushing. Four ventholes lead from a cavity in the bushing and permit the escape of gas to the rear in case of a ruptured primer. On the rear face of the breech-block are cut gear teeth, in which the gear teeth of the operating lever bevel- gear mesh. The breech-block is concentrically mounted on a hub on the block carrier, in which the firing-lock case is fitted. Its position in the breech of the gun with reference to the axis of the bore is eccentric. 10. The breech-block is closed or locked by a continuous movement of the operating lever. When the block is swung to the closed position the front face of the block latch comes in contact with the rear face of the breech of the gun, thus forcing the latch out of the notch in the breech-block and back into a recess in the carrier. By continuing the motion of closing the mechanism, the breech-block is then rotated on the hub of the carrier and its threads engage with corresponding ones in the gun. When the breech-block is in the closed position, a lug on the firing-lock case serves to lock the carrier to the breech-block and prevents displacement due to a blowback. 11. The firing mechanism belongs to that type known as a continu- ous-pull mechanism; that is, no cocking of the firing-pin is required. The firing-lock case is eccentrically fitted in the hub of the block carrier, in such a position that the axis of the firing-pin is always in line with the bore of the gun. The vent bushing in the front end of the breech-block, through which the firing-pin passes when in the fired position, is fitted eccentrically with reference to the breech-block. This eccentric arrange- ment of the breech-block, masks the point of the firing-pin and prevents any possible contact between the pin and the primer in the cartridge case when the block is unlocked. The block will be practically fully locked before any contact between the firing-pin and primer can take place. 12. Nomenclature of important parts of Breech & Firing Mechanism. Mod. 1905 : Name of Part Where located Breech Block On block carrier Vent Bushing Front end of block Block Carrier Hinged to jacket; supports block Block Stop Screwed into front face of carrier Hinge Pin Hinges carrier to j acket Hinge Pin Catch In hinge pin Extractor . . Tn breech recess Extractor Lever Mounted on hinge pin Operating Lever Pivoted on block carrier Lever Pivot Pivots lever on block carrier Lever Latch In operating lever Lever Latch Spring In operating lever, lower part Lever Latch Pivot. . . In operating lever, lower part Block Latch In recess in carrier Block Latch Spring Around latch bolt Firing Lock Case In hub of the block carrier Locking Bolt Nut & Pin. . . .On firing lock case, rear face of carrier Firing Pin In axle hole, center of firing lock case Firing Pin Spring Around firing pin Firing Spring Sleeve Around firing pin spring Sear In slot in firing lock case Trigger Fork Rear end firing lock case Trigger Shaft On rear end firing lock case Trigger Shaft Detent On trigger shaft Firing Pallet. . , On pallet shank Pallet Shank On recoil lug of gun Firing Handle On firing handle shaft Firing Handle Bracket Attached to right side of cradle Firing Handle Shaft Assembled in bracket, right side of cradle Trip Latch Attached to trip latch plunger Trip Latch Plunger Assembled to firing handle Adjusting Screw Assembled to firing handle bracket Check Nut Assembled in adjusting screw THE GUN CARRIAGE (Figs. 3 and 4) 13. The gun carriage for the 3-inch gun Model 1905 is of the type known as the long-recoil, in which the gun is permitted a sufficient length of recoil (about 45 inches) upon the carriage to render the latter stationary under firing stresses. The gun is mounted upon a cradle which forms a housing for the recoil-controlling parts. The cradle rests upon the rocker and has a small traversing motion of 70 mils on each side of the axis of the carriage. The rocker is journaled upon the axle and its rear end is supported by the elevating mechanism, which is seated in the trail. The principal parts of the carriage are the wheels, axle, trail, and elevating mechanism forming the lower carriage, the cradle and recoil- controlling parts constituting the upper carriage, and the rocker and traversing mechanism intermediate between the two. In addition there are provided shields, ammunition carriers, the road brake, and the axle seats. 14. The Wheels and the Axle, The wheels are a modified form of the Archibald pattern, 56 inches in diameter, with 3-inch tires. The axle is hollow and forged from a single piece of steel. The wheels are held on bv the wheel fastenings. (Fig. 24). CO , to s Fig. 4 <3fnc7i Gun J O _ 5. JO IS 20 ff 30 JS 40 +5 SO 15. Trail* The trail consists of two steel flasks of channel section with the flanges turned inward, tied together by transoms and plates to form the sight and the tool boxes. Attached to the trail are the trail spade, float, trail hand-spike, trail handles and the lunette. 16. Elevating 1 Gear* The elevating gear (Fig. 5) is of double- screw type and consists of an inner and outer elevating screw, an elevating-gear bracket, an elevating bevel gear, two elevating bevel pin- ions, and two elevating crank shafts. The inner elevating screw is a steel screw, threaded with a right-hand thread. It is attached at its upper end by the elevating pin to the rear end of the rocker. The outer elevating screw is of bronze and is threaded on the exterior with a right-hand thread to take the inner elevating screw. On the exterior are niso cut two longitudinal keyways, in which the keys of the bevel gear work. 17. Traversing Mechanism* The traversing mechanism (Fig. 6) consists of a shaft, called the traversing shaft, mounted in bearings in {he traversing-gear case, and a traversing nut moving longitudinally on the shaft, but restrained from turning with it by its bearings in the gear case. A cylindrical lug on top of the nut fits in a hole in a bronze tra- versing link, the right end of which is pivoted by the traversing-link pivot to the traversing lug on the underside of the cradle. This pivot is secured to the cradle-traversing lug by a nut and split pin. The left bearing of the traversing shaft is split for the purpose of assembling and rests between two collars on the shaft. The bearing, with the shaft in place, is slipped into its seat in the gear case, where it is held in position by two pins. 18. The Cradle, Complete. The cradle supports the gun, guides it in recoil, and forms a housing for the recoil-controlling parts ; it consists of a flange steel body with the upper edges flanged outward. The flanges are bronze lined, engage the clips on the gun, forming the guide rails for the gun on recoil. Riveted to the bottom of the cradle are four steel forgings, the pintle, traversing lug, rear clip, and elevating and traversing lock lug. The pintle fits the pintle socket in the rocker and forms a bearing upon which the cradle is traversed. The traversing lug has been heretofore mentioned as affording a point of attachment for the traversing-link pivot. The cradle rear clip, in addition to em- bracing the rear end of the rocker, has a broad bearing on the latter directly over the point of attachment of the elevating screw. To relieve the pointing mechanism from all strains in travelling, an elevating and traversing lock is provided, by which the cradle may be locked to the trail. 19. The recoil mechanism (Fig. 7) contained inside the cradle con- sists of the cylinder, the piston rod, the counter-recoil buffer, the coun- ter-recoil springs, and the spring support. To the rear end of the cradle is riveted a steel cradle head, rear, through which the cylinder moves in recoil and projects for attachment tc the recoil lug on the gun by means of the cylinder end stud and nut. The front end of the cradle is closed by the cradle heaql, front, and the retaining ring. 20. The cylinder lies inside the cradle and is surrounded by the coun- ter-recoil springs. Its rear end is closed and has a projection on the inside to which is screwed the counter-recoil buffer, a tapered bronze rod which fits with small clearance into a bore at the rear end of the piston-rod. The front end of the cylinder is closed by a bronze oil- tight gland, through which the piston-rod slides. The cylinder is filled with a neutral oil called hydroline. The interior of the cylinder is cylindrical. Three longitudinal ribs or throttling bars of uniform width but varying height extend along the interior from the rear end to within 19 inches from the front end. Three notches are cut in the piston head; forming ports for the passage of the liquid from one side of the piston to the other. The height of the throttling bars is calculated so that the resistance which the liquid offers, plus the resistance of the springs, is constant and such that the recoil will be checked at the desired point. During recoil the front end of the cylinder is supported by the spring support. 21. The piston rod is of steel, and is provided with a bronze piston head, screwed against a shoulder at the rear end. The head has three notches cut in its perimeter, which fit over the throttling-bar projections on the cylinder wall. The rear end of the piston is bored out to take the counter-recoil buffer. In counter recoil the oil in this bore can es- cape only by a small clearance. In this way the return of the gun into battery is so eased and regulated that very little shock and consequent derangement of the aim of the piece occur. The front end of the piston rod is attached to the cradle head, front, by means of the piston rod nut. 22. The counter-recoil springs (three in number, each 36 inches long) are helical, being made from a rectangular steel bar coiled on edge. They are assembled in the cradle, end to end around the cylinder and bear in front against the spring support and in the rear against the cradle head, rear. They are assembled under an initial compression of approximately 750 Ibs. which is sufficient to return the gun into battery at the maximum elevation. In place of the single counter-recoil springs a set of three inner and three outer counter-recoil springs is also being issued. 10 in bO 23. The spring support forms a support for the front end of the cyl- inder and a bearing for the front end of the spring column. It has guide lugs which fit into and glide along guide rails inside the cradle during recoil. The spring support is held in place by the retaining rin^. ACTION OF THE MECHANISM (Fig. 7) 24. The action of the recoil mechanism when the gun is fired is as follows : The gun moves to the rear 45 inches on the cradle, carrying with it the cylinder and compressing the recoil springs. The piston rod being attached to a fixed part of the carriage in front (the cradle-head), does not move. Therefore, since the cylinder moves to the rear, trie oil in it must pass from one side of the piston-head to the other. The energy of recoil of the gun is therefore absorbed by the resistance which the oil offers when being forced through small openings between the notches in the piston-head and the throttling bars along the inside of the cylinder and also by the resistance of the counter-recoil springs to additional compression. The energy stored up by the springs during this compression, returns the gun and cylinder to the firing or original position. This return movement is eased and regulated by the counter- recoil buffer. The piston-rod pull and the spring resistance are trans- mitted to the carriage, but owing to the latter's weight and the resis- tance opposed to the trail spade by its engagement in the ground the carriage remains stationary. WEIGHTS AND DIMENSIONS 25. Weight of gun and carriage complete 2,520 Ibs. Width of track 60 inches Length of recoil on carriage 45 inches Amount of traverse of gun on carriage 140 mils 26. Nomenclature of important parts of the Gun Carriage : Axle Wheel guards Trail, consisting of Trail handles Flasks (right and left) Trail seats Tool box Trail-seat supports Elevating gear transom Sponge-staff socket Rear sight box Name plate Spade Handspike Spade edge Lunette Float Cradle, consisting of Handspike fulcrum Cradle body 12 to (^ . Cradle head, rear Gun slides or Guide Rails Cradle Pintle Traversing lug Rear clip Lug for elevating and traversing lock Bracket seat, firing handle Quadrant fastening Rear-sight bracket support Front-sight bracket support Spring-support guides Retaining ring, with hasp and fastening Cradle head, front Shoulder guard Cradle brush Recoil-indicator throw Recoil indicator Cylinder head Cylinder with cylinder end screwed in Cylinder end stud and nut Counter-recoil buffer Rings, packing Gland Piston rod, with plug, screwed in Piston Piston-rod nut Filling plug with gasket Drain plug Spring support Counter-recoil springs Rocker Cradle Pintle socket Elevating and traversing lock Traversing mechanism, consisting of Traversing-gear case Traversing plate Handwheel with handle and spindle Traversing shaft Traversing-shaft bearing in two parts ^ Traversing link with bushing Traversing-link pivot with nut Azimuth pointer and scale Elevating mechanism, consisting of Elevating pin Inner elevating screw Outer elevating screw Elevating bevel gear Elevating bevel pinions Elevating crank shafts, with handles Elevating screw cover Axle seats, include Seat arms Seat-arm guards Foot rests Tie rods Shield braces Apron shield Apron latches Main shield, consisting of Main shield Hood Shutter, open-sight port Shutter, panoramic-sight port Top shield, consisting of Top shield Top shield fastenings Road brake, includes Brake beams Brake shoes Springs with covers Brake rods Brake lever Brake shaft Brake segment with two segment racks Ammunition- carriers Range quadrant case Panoramic sight case Front sight Reaf sight, consisting of Rear-sight bracket with shank socket Rear-sight shank Panoramic sight Range quadrant Wheels, consisting of Felloe, segments Spokes Tires Hub boxes Hub liners Hub-latch plungers Oil valve Carriage bolts and nuts Hub bands Hub caps Wheel fastenings Plugs THE 3-INCH GUN (CAISSON) LIMBER (Fig. 8) 27. The limber is of metal throughout excepting the spokes and fel- loes of the wheels. The principal parts are the wheels, axle, pintle, frame, ammunition chest, pole, doubletree, singletrees, and neck yoke. 14 t- o to 28. The wheels and wheel fastenings are the same as, and inter- changeable with those used on the carriage. Seats for three cannoneers are provided by a perforated metal bucket-holder on top of the chest. The paulin issued to each limber serves as a seat cushion and is held in place by paulin straps. Grip straps are also provided for use by the cannoneers when the carriage is moving at rapid gaits. On the sides c-.nd front of, and under the ammunition chest, suitable straps, brackets c-nd connections are provided for securing all tools and accessories. \Yith each limber are issued three tubular oil cans, each in the form of a cartridge and with a capacity of two-thirds of a gallon. These are intended to hold hydroline, lubricating and coal oil and are carried in the central row of cartridge holes in the ammunition chest. WEIGHTS AND DIMENSIONS 29. Weight of limber, completely equipped and loaded. . . 1740 Ibs. Weight of gun, carriage and limber, completely equipped and loaded 4260 Ibs. Number of rounds carried 36 30. Nomenclature of important parts of limber : Pole, complete, consisting of Pole body Neck-yoke counter stop Neck-yoke stop Neck-yoke chafing plate Butt reinforce Doubletree Doubletree rods Name plate Limber prop Foot rest Tie-rods Pintle with bearing, consisting of- Pintle Pintle latch Pintle latch spring Wheels and wheel fastenings Axle Middle rail Side rails Ammunition chest, consisting of Hand rail Door chains Shot bolts Bucket holder Chest rails Chest-rail connections Body Door Cartridge holes Diaphragms Lantern brackets Grip-straps Paulin straps Various tool brackets Various tools Paulins Picket ropes Lanterns Canvas buckets THE CAISSON (Figs. 9 and 10) 31. The Caisson is made of metal throughout with the exception of the spokes and felloes of the wheels. The principal parts are the wheels, axle, pintle, lunette, apron shield, fuze setter bracket, frame, road brake, and ammunition chest. 32. The wheels and wheel fastenings are interchangeable with those of the prings and the retaining ring being in assembled position, shove the cylinder (turned so that the drain plug in cylinder head comes on top) into its seat from the front, with the projecting stud on the recoil lug of the gun entering one of the recesses provided for it in the cylinder 97 end ; assemble the cradle head ; screw in place the piston-rod nut and cylinder-end stud nut. Be sure that the projecting stud on the gun enters one of the holes for it in the cylinder end before screwing the cylinder-end stud nut up all the way. 42. To assemble the parts of cylinder after cleaning* The parts should be reassembled immediately after cleaning and inspection (see Par. 122), and the cylinder filled with hydroline oil (see Par. 123) issued for that purpose. (For cleaning cylinder oil, see Par. 125.) The piston should be moved back and forth in the cylinder by hand to make sure that all parts are correctly assembled and are without interference. The cylinder should then be assembled in the cradle (see Par. 41) and the gun pulled from battery by hand and permitted to counter-recoil rapidly to insure that all parts are in proper position for firing. This should never be done, however, unless the cylinder is known to be filled with oil. In reassembling the parts the condition of the vulcanized-fibre washers between cylinder head and cylinder, and between cylinder-end stud and cylinder end should be noted ; they should be replaced when- ever necessary to prevent leakage. In removing and inserting the piston rod care should be taken to keep it central in the cylinder, so as not to bind, burr, or spring any parts. The dismounting and reassem- bling of the parts of the cylinder should in every case be supervised by a commissioned officer. Before firing an inspection should be made to ascertain that the different parts, especially the piston rod and the cylin- der-end stud nuts, are correctly assembled. NOTE : For instruction in cleaning and care of materiel, see. Par. 122 to 131. 43. To pack the stuffing box. The stuffing box is packed with five rings of Garlock's hydraulic waterproof packing, 0.25 inch square. The packing is issued cut into rings of such size that the ends meet around the piston rod. The latter being assembled, each ring, placed so as to break joints with the preceding one, is forced in succession into its seat by a packing tool of copper or hard wood, one end of which is shaped like a carpenter's gouge and the other end forms a handle strong enough to stand light taps from a hammer. Such a tool may be readily improvised by one of the battery mechanics. After the five rings are firmly seated in the box, screw the gland down on the packing. In assembling the gland be sure that at least four of its threads are engaged with the threads of the cylinder head ; otherwise the threads of the gland may be stripped in firing. With new packing it may be found difficult to insert more than four rings and secure sufficient en- gagement of the gland. In such a case the box should be packed with 23 four rings and the piece fired a few rounds, after which the fifth ring should be inserted. 44. Adjustment of the gland* The adjustment of the gland will re- quire the exercise of some judgment. If screwed up too tight, the fric- tional resistance of the packing on the piston rod will be increased so much that the counter-recoil springs may fail to return the gun to bat- tery, especially at high angles of elevation. It should be screwed up just tight enough to prevent the leakage of oil through the stuffing box. Ordinarily this can be done by hand, but in cases where hand power is not sufficient the wrench provided for the purpose should be used. When its proper adjustment is determined, the gland should be lashed with copper wire to prevent it from screwing up or unscrewing. 45. To remove the piston rod. Unscrew the gland sufficiently to release the pressure of the packing upon the rod ; unscrew and remove the cylinder head. The rod may then be withdrawn from the cylinder. In dismounting and assembling the cylinder head (and also the cylinder- end stud), the cylinder should be held from turning by a spanner ap- plied to the head retainer or flange on the front end of the cylinder. // should never be clamped in a vise, as its walls are thin and not in- tended to withstand such usage. 46. To remove the counter-recoil buffer* Remove the cylinder-end stud screw; unscrew and remove the cylinder-end stud; the counter- recoil buffer is attached to the latter. 47. To dismount the springs* Bring the gun to approximately zero degrees elevation; unscrew the cylinder-end stud nut and the piston- rod nut ; shove the gun about 1 inch from the battery ; attach the sleeve end of the spring compressor to the cylinder-end stud and put sufficient strain on the compressor to relieve the retaining ring from spring pres- sure; then remove retaining ring (and cradle head) by loosening and swinging aside the retaining-ring bolts ; ease off slowly on the spring compressor until the springs are free. 48. To assemble the double counter-recoil springs. With the cradle at maximum elevation and the trail horizontal, place one outer and one inner spring in the cradle until the front ends are about 2 inches in ; set up a separator against the forward end of these sections and enter the second outer and inner springs, keeping the separator up- held between the sections ; similarly when the outer end of the second section is 2 inches inside the cradle set up the second separator ; place the third outer and inner sections on the recoil cylinder. Screw the spring centering tool onto the cylinder-end stud, the small end pointing rearward; pass the sleeve end of the spring compressor through the gun lug and the inner springs and attach it to the cylinder-end stud. 24 Enter the rear end of the cylinder in the spring at the front end of the cradle and push ^the cylinder back until the springs are at free height, keeping the spring compressor taut. Attach the block and fall carried in the battery wagon to the spade of the carriage or to some improvised support and connect it to the spring compressor; put suf- ficient strain on the spring compressor to bring the spring column to its assembled height. As the spring column approaches its assembled height the spring support must be turned so that its guide lugs properly enter in the spring-support guide grooves in the cradle ; assemble the retaining ring, disconnect the spring compressor and the spring centering tool from the cylinder-end stud nut. When the retaining ring is assembled the nuts for the retaining ring bolts should be screwed up until they just come into contact with the retaining ring. If these nuts are screwed up too tight they will deform the retaining ring, with the result that it becomes difficult to assemble and dismount the cradle head. A wrench is provided for turning the spring support to its proper position. 49. To assemble the single counter recoil spring. The same method (see Par. 48) is followed except that no separators are used. The spring compressor is provided with a second eye at its large end which may be used in case the sleeve end should become broken; in case this end is used, however, it will be necessary to pass the com- pressor through the cradle from front to rear, through the gun lug. For disconnecting the compressor the method used is identical to that previously described (see Par. 48 above). The cylinder-end stud nut should never be removed when the gun is at an elevation, and the gun should not be elevated when the cylinder- end stud nut is not in place. To prevent the cylinder-end stud from rotating a screw for the cylinder end is provided. This screw for the cylinder end must be removed before attempting to unscrew the cylin- der-end stud. Since the springs are assembled under an initial load of over 750 pounds, a pull of more than 750 pounds must be exerted upon the spring compressor in assembling them. This can be done by passing a hand- spike through the loop at the rear end of the compressor and making use of the services of the entire gun squad, or the block and tackle may be used as described above. To avoid the possibility of injury to the gun squad in compressing or releasing the springs, all should be required to keep arms and bodies away from the front of the spring column during these operations. , 50. To remove and to replace a pole* Remove the pole pin ; loosen 25 the clamping bolt on the right side of the pole clamp. While shaking the pole, withdraw it from its seat. The pole ferrule is detachable from the pole and may be removed after having first taken out the two steel locking pins. The spare pole is carried under the caisson frame, being held in place by the spare pole fastening and bracket. To remove the spare pole, unscrew the nut on the spare pole fasten- ing and withdraw the spare pole from the bracket. To replace the pole or the spare pole, the operations indicated above are reversed. The ends of the spare pole should be shaped and sand-papered and then oiled so that they will fit easily (not loosely) into the pole clamp seat and the socket of the pole ferrule. 51. To dismount and to assemble the traversing mechanism. Traverse the cradle (muzzle end) to its extreme left position; remove the nut which secures the traversing-link pivot to the cradle lug ; remove the traversing-link pivot from below ; turn the link so as to clear the heads of the traversing shaft-bearing pins and remove these pins ; un- screw the worm shaft from the nut and at the same time withdraw the shaft with its left bearing from the gear case. Now move the cradle in azimuth to its extreme right position ; slip the link off the nut and re- move the nut from the gear case. To dismount the left bearing, all that is necessary is to remove the adjusting nut and slip the bearing off the shaft. To assemble the traversing mechanism, the above operations are reversed. 52. To dismount the elevating screws* Remove the elevating pin :' unscrew the inner screw by hand ; remove the elevating-screw cover ; remove the outer screw by screwing it down through the elevating-gear bracket. 53. To dismount the pinions and bevel gear* Remove the taper split pin in the pinion hub, after which the crank shaft may be with- drawn and the pinion removed from its seat. The bevel gear may then be removed by dismounting the screws as above. (See Par. 52.) 54. To dismount the elevating-gear bracket* Free the mechanism from the rocker by removing the elevating pin ; dismount the pinions and crank shafts as above (see Par. 53) ; remove the eight elevating- gear transom bolts ; the bracket and transoms are then free and may be removed from the trail. 55. To assemble the elevating mechanism* The operations just described are reversed (see Par. 52 to 54). The following should be noted : The pinions are a close fit on the crank shaft, and especial care should be taken not to burr the parts in assembling. When properly located, the two crank-shaft handles balance each other. This condi- tion obtains when they are simultaneously horizontal and both pointinc/ 26 V; the front or both pointing to the rear. As the outer screw is assem- bled in the gear bracket from below, the bevel gear should be put in place with its key engaging the key ways of the screw. Before attach- ing the inner screw to the rocker both screws should be run down to be sure that the upper ends of the threaded parts of the screws are flush with the face of the gear bracket. If this condition is not fulfilled, the mechanism will not give the maximum elevation and depression for v/hich designed and will not house properly in traveling. 56. To adjust the road brake. The brake rods are disconnected from the brake beams. The brake shoes are placed with the desired clearance from the tire and the brake lever with handles in extreme for- ward (released) position. The length of the brake rods should then be adjusted to correspond. Should test show that one shoe bears harder on one wheel than the other, the brake rod of the latter should be lengthened. 57. To remove a hub cap* First lift the hub latch which removes the hub latch plunger from the hub band and then unscrew the hub cap by turning it to the left. 58. To remove a wheel* First raise the wheel by a jack; remove the hub cap, then the wheel fastening, and then the wheel. The wheel fastening (Fig. 24) is removed by lifting the wheel- fastening plunger until it is clear of the axle and then lifting the fastening off the axle. 59. To remove a hub liner* Remove the wheel from the axle and drive the liner out by striking with a heavy hammer or sledge upon the hub-liner driving tool (a bronze tool carried in the forge limber) placed against the small end of the liner. 60. To dismount the cradle* Remove the traversing gear (it will suffice to remove the traversing-link pivot and to remove the hand- wheel from the traversing shaft) ; remove the three shield bolts and shield-brace bolt ; slip end of shield brace from tie-rod fastening ; raise the right axle seat ; swing the rear end of the cradle 38 to the left, and then lift it clear of the carriage. 61. For instructions to remove the shields; to remove the apron latch ; to remove the road brake ; to assemble the axle seats and am- munition carriers ; to dismount the trail and rocker ; see pp. 81 to 83 inc., Handbook for the 3-inch Gun Materiel, 1916. SIGHTS AND OBSERVING INSTRUMENTS 62. The sights, quadrant, B. C. Telescope, aiming circle, field glasses and range finder, are all delicate instruments. They should be handled with the very greatest care and when not in use should be properly replaced in the carrying cases or boxes provided. 27 63. The following things should be forbidden: To turn unnecessarily any worm knobs ; to tighten or to release unnecessarily any clamps ; to disassemble for adjustment the interior mechanism ; to file or to tap or hammer any of the parts ; to use force in manipulating any of the parts, clamps or worm knobs ; to polish any of the parts ; to use alcohol, petroleum, glass polish, soap or other agents in cleaning the lenses. 64. Examination by enlisted men should extend only to the outer condition and serviceability, and whether the parts function properly. All scales must show clearly; indexes of scales and micrometers must coincide. Level vials must be intact and bubbles not too large. All worm knobs and gears should work smoothly, without lost motion and without binding or jumping. The optical instruments are issued to troops sealed against dust and moisture. Under no circumstances will these internal parts be unsealed, because the instrument may thereby be seriously damaged. The field of view must be clear. In field glasses and in the B. C. Telescope, the fields must be coincident so as to form a single image. The graduated cross wires must be upright and focused so that the image will be sharply defined. During cold weather the eyes should not be brought too close to the eye pieces, otherwise vapor will condense on the lenses. 65. Care and Cleaning* All traces of dust or moisture to be re- moved before putting away. Carrying cases and boxes should be stored in a place which is dry, free of dust and only moderately warm. If moisture has collected on the glasses, place instruments in gentle warmth. Exposed bearing surfaces should be only lightly oiled and sur- plus oil wiped off, care being taken to keep the glasses free from oil. Lenses and glasses are dusted with the camel's hair brush provided. When necessary use cleaning cloth or chamois skin, free of grit or dirt, for cleaning lenses. In this case do not apply much pressure in wiping off. Never use a rough, dirty or woolen rag. Never use the O.D. shirt, O.D. coat or a dirty handkerchief on the lenses. If cleaning cloth or chamois skin is not available, the best substitutes are a piece of rumpled toilet paper, a silk or soft linen handkerchief. Never expose unnecessarily to extreme cold, to the direct rays of the sun, or the heat of a stove or radiator. Carrying cases and boxes must be in a serviceable condition. Padding and brackets must be intact and hold instruments securely in place. Locks and clamps in good order. 66. Full descriptions and instructions in the care and adustment of sights and quadrants are given on pp. 119 to 140 inc., Handbook for V 28 f fill III the 3-inch Gun Materiel, 1916. Attention is invited to G. O. No. 47, W. D., March 24, 1905, with reference to the care and repair of pano- ramic sights. A complete description and full instructions in the care and adjustment of all F. A. Observing Instruments will be found in the Handbook of Fire Control Equipment for F. A., 1916. The permissible disassembling of telescopic instruments, must 'be done only in the presence of an officer. Ordnance Office Pamphlet No. 1795, gives very detailed descrip- tions of the methods of disassembling, repairing mechanisms and optical systems, as well as optical adjustments. Disassembling as permitted therein may be done only by officers and employees of the Ordnance Department. SIGHTS 67. The instruments provided for sighting and laying the gun include a line sight, a rear sight, a front sight, a panoramic sight, and a range quadrant. 68. Line sights* The line sight consists of a conical point as a front sight and a V notch as a rear sight, located on the top element of the gun. They determine a line of sight parallel to the axis of the bore, useful in giving general direction to the gun. (Fig. 1.) 69. Front and rear sights* The front and rear sights are for gen- eral use in direct aiming. The front sight carries cross wires. The rear sight is of the peep variety, constructed as follows : To the sight bracket is attached the shank socket upon which a spirit level is mounted for the necessary correction due to difference in level of wheels. The sight shank consists of a steel arc, the center of which is the front sight. It slides up and down in the shank socket and is operated by a scroll gear. A range strip is attached to the face of the shank and is gradu- ated up to 6500 yards, least reading 50 yards. To the left side of the shank is an elevation spirit level, permitting approximate quadrant elevations to be given with the sight shank when the quadrant is out of order. The peep sight and its deflection scale are mounted above the shank. This peep traverses along a screw operated by a knurled head. A socket and ratchet are also provided for the attachment of the pano- ramic sight. 70. Nomenclature of the important parts of the Rear Sight : - (Fig. 11) Peep sight Shank socket Elevation level Cross level Deflection scale Leveling screw Peep sight screw and head Scroll gear and handle Range strip Rear -sight bracket Shank Panoramic sight socket and ratchet 30 Panoramic Sight, Model of 1915 (Fig. 12) 71. The panoramic sight is a vertical telescope so fitted with an optical system of reflecting prisms and lenses that the gunner with his eye at the fixed eyepiece in a horizontal position can bring into the field of view an object situated at any point in a plane perpendicular to the axis oi the telescope. The rays coming from the object are reflected downward from the rotating head prism into the rotating prism. The rotating prism rectifies the rays; after their passage through the achromatic objective lens, the lower reflecting prism reflects them in such a way that there is presented to the eyepiece a rectified image, which the eyepiece magni- fies. A glass reticule marked with graduated cross lines is located in the focal plane of the instrument, with the intersection of the cross lines coincident. The instrument has a universal focus, a magnifying power of 4 and field of view of 180 mils. 72. The principal parts of the panoramic sight are the rotating head, the elevation device and its micrometer, the azimuth mechanism with limb and micrometer, the rotating prism mechanism, the deflection mechanism, R and L scale and micrometer, the shank and the eye piece. The limb or azimuth scale is divided into 64 parts, each division representing 100 mils. The azimuth micrometer is divided in 100 equal divisions or mils, numbered every 5 mils. One complete revolution of the azimuth micro- meter is equal to the distance between divisions on the azimuth scale. The limb of the deflection scale is divided into six divisions ; three on each side of the zero, red for right and black for left, each division representing 100 mils. The deflection micrometer, engraved upon the front end, is graduated into 100 equal divisions, numbered every 10 mils, red and black in opposite directions. The Range Quadrant (Fig. 13) 73. The range quadrant consists of the quadrant spring fastening and bracket, rocker, body, scroll gear, range disk, range and cross levels with suitable leveling screws, and a micrometer to set off the angle of site. The range disk is graduated to 6500 yards, least reading every 50 yards, scale numbered every 500 yards. This disk is operated by a 32 scroll gear. Large changes in range may be made by pulling out the hand-wheel, thus disengaging the scroll gear, and moving the body and index to the approximate range, whereupon the hand-wheel is released nd the range accurately set by again turning the hand-wheel. The micrometer has 100 divisions and is operated by a milled head. The limb of the micrometer, called the level scale, is graduated from 2 to 5, each division corresponding to one complete revolution of the micrometer. The arbitrary reference point or mean position of the level holder is 300 which corresponds to a point on the same level as the gun. CARE AND INSPECTION OF SIGHTS 74. Rear Sight Bracket. Should not be bent, broken or cracked. Must be seated firmly in the bracket support. Shank Socket Mechanism. Not bent or burred; interior of shank socket, scroll and worm gears free of scratches, burrs or de- formed threads. Sight shank easily inserted and moved up and down in the socket. Scroll gear securely held in mesh with rack of sight i'hank. For large movements of shank, should be easily disengaged by pulling out scroll gear handle ; must be securely held in place by spring- when released. Keep interior well lubricated. See that level vials of cross and elevation levels are intact and bubbles not too large. Sight Shank. Rack on right side must engage with scroll gear; keep lightly oiled. Sight shank should remain in fixed position except when disengaged or operated by scroll gear handles. For changes in range of 300 yards or less use only the scroll gear ; over 300 yards pull scroll gear handle and slide shank up or down in socket by hand, making accurate setting with the scroll gear. Panoramic Sight. Lug must fit snugly in T slot of rear sight and then held fast by clamp screw and ratchet. When making ready for march order, first set the azimuth and R & L deflection scales at z^ro, and the elevation scale at 300. Release clamp screw and ratchet. In removing panoramic sight, grasp at center below the azimuth gear case, lift vertically out of the socket, lower the top of sight to the left and replace in panoramic sight box. Quadrant. Must fit snugly in its bracket, spring catch engaging. Nut on range disk must be tight to prevent slipping. To remove quad- rant, press on spring catch before sliding off bracket. 34 FIELD ADJUSTMENT OF SIGHTS AND QUADRANT 75. The sights are correctly adjusted when, at zero elevation and de- flection, correction having also been made for difference of level of xvheels, the line of sight is parallel to the axis of the bore. 76. The range quadrant is correctly adjusted when, with the range disk set at zero, level set at 300, axis of gun horizontal and corrected for difference of level of wheels, the bubble of the range level is centered. 77. In adjusting sights, the panoramic sight should first be corrected. Jf the rear sight is adjusted first, it will require readjustment if the subsequent adjustment of the panoramic sight causes a change in posi- tion of the rear-sight range strip. 78. To adjust the panoramic sight* Select a well defined point at least 2000 yards distant. If the bore sights are not available, stretch two threads or hairs from the tail of a horse across the grooves marked on the face of the muzzle and fasten them by a strap or rubber band Remove the firing-lock case from the hub of the block-carrier. By sighting through the hole in the vent bushing of the breech-block, adjust the intersection of the cross hairs on the distant point, using the elevat- ing and traversing mechanisms of the gun. Now without moving the gun or disturbing the laying of the cross hairs, bring the cross wires of the panoramic sight on the same distant point by means of the azimuth .scale worm-knob and the scroll gear of the rear sight (on panoramic sights, M 1915, to the deflection R & L scale should first be made to read o, and the deration scale of the objective to read 300). The cross hairs of the gun and the cross wires of the panoramic sight will thus be bid on the same point. Now adjust the azimuth micrometer scale to read by means of unscrewing and tightening the screw on the milled head. Loosen the nut on the range strip ; move it up or down until it reads (0) 100. Tighten the nut again. Verify the laying. For this adjustment, it is not necessary to have the wheels or the carriage on a level platform ; cross level should be leveled. 79. To adjust the rear sight* Having adjusted the panoramic sight and the rear sight range strip as described above, and without disturb- ing the laying of the gun, shift the deflection scale of the peep sight and raise or lower the front sight until the cross wires of the latter are laid upon the same distant point. Now loosen the two screws of the deflection scale and place the of this scale opposite the index of the peep sight. The front sight is raised or lowered by removing the split pins and then turning the front sight in the sight bracket sleeve either tip or down. 35 80. To adjust the quadrant* (a) If an adjusted B. C. telescope or another gun with its quadrant in proper adjustment is available, the angle of site of some distinctly visible and distant point is measured by either of these means. The gun to be adjusted is then laid upon this distant point either with the bore sights, or with the tangent sight set at G (or some other convenient) range. The measured angle of site is then set off on the level scale of the quadrant and the bubble of the range level is centered by turning the hand-wheel of the range disk. By using the quadrant wrench, the range disk is then adjusted to read range (or the convenient range previously set off on the tangent sight). (b) If no means are at hand to correctly measure the angle of site of a distant point, the quadrants may be adjusted by using two guns as follows : Unlimber two guns at about the same level, first seeing that the sights are in adustment (Par. 75). Lay both guns upon some distant point by means of the panoramic sight set at range. Now set both quadrants for the same angle of site (roughly estimated A. S. of the distant point) and center the bubbles of the range level by turning the hand-wheel of the range disks. By means of the quadrant wrench, adjust the range disk of one of the quadrants to agree with the other. Whatever error exists will now be the same in each quadrant. Now move one of the guns about 100 yards away and turn the muzzles toward each other. With the sights set at range, lay the paroramic sights upon each other and measure the angle of site of each gun. Half the difference of the two readings will be the slope of the line of sight between the two guns. On the level scale of the quadrant which read the greater angle of site, set off 300 plus the half-difference, on the other quadrant set off 300 minus the half-difference. Now center the bubble of the range level by turning the hand- wheel of the range disk. By using the quadrant wrench, adjust the range disk until h reads range. Having thus adjusted two guns, the others may be adjusted by the first means described. OBSERVING INSTRUMENTS B. C Telescope, M. \9\5 (Fig. 14) 81. The B. C. Telescope, M. 1915, is a binocular observing instru- ment of the scissors type. The two tubes of the telescope may be clamped either in a vertical or a horizontal position. In the former position the objectives are 12 inches above the eyes of the observer, and in the latter position they are 24 inches apart and at the same height 36 as the eyes of the observer. In both cases they permit the observer to take advantage of some shield or other cover and still obtain a full view of the sector of observation. The tubes may be adjusted for the observer's interpupillary distance in either the vertical or the hori- zontal position. The eyepieces may be adjusted to the eyes of the ob- server by screwing in or out. 82. The principal parts of the telescope are: Leveling mechanism, azimuth mechanism, elevating mechanism, angle of site mechanism, the telescopes and the tripod. A carrying case is provided separately for the instrument and for the tripod. In garrison a storage case is also provided. The leveling mechanism consists of a ball and socket joint oper- ated by the vertical spindle clamping screw. The azimuth mechanism consists of the azimuth worm knob with its lever, operating the azimuth worm and worm wheel; the adjusting or slow motion knob and the azimuth clamp. The azimuth limb is divided into 64 parts, each division representing 100 mils. The azimuth micrometer is divided into 100 equal parts or mils, numbered every 10 mils. One complete revolution of the micrometer is equal to one division of the limb. The scales therefore correspond to those on the panoramic sight, 6400 mils to the circumference. The leveling mechanism is operated by the small elevation worm knob. The angle of site mechanism consists of the level, the angle of site scale and micrometer with its worm knob. The telescopes consist of the eyepieces, telescopic tubes with their optical systems. In the right eyepiece is a graduated cross wire which can be rotated for either the horizontal or the vertical position. The tripod is similar to the usual telescopic instrument tripod. The optical characteristics of the instrument are as follows : Power 10; field of view 75 mils ; focal length of objectives \\ l /2 inches ; the field is flat, free from chromatic and spherical aberration, coma and distortion. Care and Instructions 83. To set up the telescope. First set up the tripod, clamping and propping the legs so as to obtain the desired cover and view. By means of the vertical spindle clamping lever, approximately center level on azimuth worm case and clamp tightly. Carefully take out B. C. tele- scope from case and while pressing on locker plunger, place telescope on vertical spindle so that the projection on the azimuth worm case 37 will tit the corresponding slotted segment of the telescope. Release the locking plunger. To focus the eye pieces* Adjust each eye piece separately by turning the same until the image of a distant object appears sharply defined. Read the diopter scale, plus or minus, and note for future use. To adjust the interpupillary distance* The eye pieces having been focused, loosen the large friction clamp knob in front. Grasp both tubes with the hands and separate or close them in (either in the vertical or horizontal position) until the fields of view of the two eye- pieces are exactly coincident and present a single image to the eyes. This can be tested by alternately closing one eye and then the other, noting any movement in the image. Tighten the large friction clamp knob. Read the interpupillary scale and note for future use. 84. To lay on any point* Level the instrument by means of the vertical spindle clamping screw. Bubble must remain approxi- mately centered while instrument is turned 1600 mils. Set both the azi- muth index and the micrometer to read zero. Release the azimuth clamp shaft knob ; turn the telescope toward the point and tighten the azimuth clamp shaft knob. Bring the vertical wire accurately on the point by turning the azimuth adjusting worm knob. To measure the deflection and site of a target* Lay the zero on the aiming point as above. If the line of sight must be moved through a large angle, press down the azimuth worm lever as far as it will go and while holding it down move the azimuth mechanism until the line of sight is approximately directed upon the target ; then release the worm lever and bring the cross wires accurately on the target by turning the azimuth worm knob (for deflection) and the elevation \vorm knob (for elevation). Center the site level. Read the deflection and site. For carrying the B. C. telescope assembled on the tripod, clamp' tightly the vertical spindle clamping lever ; close in and clamp the tubes of the telescope ; slide up and clamp the lower tripod legs ; then carry the telescope over the shoulder by grasping the tripod legs, tube bases of telescope resting on the shoulder. 85. To dismount the B C* Telescope and to pack in carrying case* Screw in both eye pieces. Press on the locking plunger and lift the telescope vertically oft" the spindle. Unclamp the large friction clamp knob, bring the tubes together and insert in the carrying case; close and lock the lid. In dismounting the tripod the leg separators of the upper sections should first be undamped. After the lower legs have been assembled, they should be clamped. To set up the tripod the oper- ation is reversed. 38 Aiming Circle, M* J9J6 (Fig. 15) 86. The Aiming Circle is an angle measuring instrument only and consists of a telescope, leveling mechanism, angle of site device, eleva- ting mechanism, azimuth circle and compass, mounted on a tripod. Its leveling, azimuth and angle of site mechanisms are similar to those in the B. C. Telescope, as is also the tripod. The elevating mechanism consists of (a) elevating worm knob and gear connecting it with the telescope. The telescope lias a universal focus, magnifying power of 4, and a field of 180 mils. The cross wires are illuminated by a window. The compass is secured by the needle release button. Care and Instruction. 87. Glass compass cover should fit tightly. Compass needle when clamped should not rotate while instrument is revolved or tipped. When release button is pressed, compass must swing freely on pivot and again remain clamped when button is released. Compass should be released only when aiming circle is set up and horizontal. Bubble must remain approximately centered while instrument is turned 1600 mils. 88. To lay on any point* Set both the azimuth index and the micrometer to read zero. Release the wing nut; turn the telescope toward the point and again tighten the wing nut. Bring the vertical wire accurately on the point by turning the adjusting worm wheel. To measure the deflection and site of a target* Lay on the aiming point as above. If the line of sight must be moved through a large angle, press down on the azimuth worm lever as far as it will go and while holding it down, move the azimuth mechanism until the line of sight is approximately directed upon the target; then release the worm knob (for deflection) and the elevation worm knob (for eleva- tion). Center the site level. Read the deflection and site. 89. To measure the compass deflection of a target* Set both the azimuth index and the micrometer to read 0. Release the wing nut ; turn the telescope until the N and S poles of the compass are respec- tively near the N and S points marked on the compass box. Make the coincidence accurately with the adjusting worm wheel. Now proceed to measure the deflection and site of the target as described above. In the latest type of Aiming Circle, the interior of the compass box is graduated in mils. This simplifies the measurement of a com- pass deflection. With the instrument reading 0, the line of sight is laid upon the target. Now press the needle release button and when the needle stops swinging, read the compass deflection. 90. The Tripod and Azimuth Gear Case. The leather cover pro- tecting the ball and socket joint must fit snugly both above and below, 40 AIMING CIRCLE Fig. 15 and be free of rips or holes. The ball and socket joint and the tripod legs should be easily adjusted and moved, but should remain fixed when clamped by the clamping levers. For carrying the aiming circle assembled on the tripod, the wing nut and the vertical spindle clamping lever should be clamped tightly and the instrument carried over the shoulder by grasping the tripod legs, head of tripod resting on the shoulder. ADJUSTMENTS B. C TELESCOPE AND AIMING CIRCLE 91. The B. C. Telescope and the Aiming Circle are correctly adjusted when the following conditions prevail: Telescope properly focused; plane of level perpendicular to the vertical axis of the instrument ; angle of site scale reading 300 when the line of sight is horizontal; lost motion on worm gears eliminated. In principle, the adjustments of the B. C. Telescope and of the Aiming Circle are exactly the- same. The leveling and focusing have already been described. Detailed instruc- tions of the operations in eliminating lost motion in the worm gears will be found in the Handbook for F. A. Fire Control Equipment, 1916. 92. To make the site scale read 300 when the line of sight is horizontal* Set up the telescope or aiming circle. Level the in- strument so that the bubble on the azimuth worm case will remain centered while the instrument is turned 1600 mils. Lay on some point of a stake or other "vertical linear object which is at a convenient dis- tance but not closer than 100 yards to the instrument. The point se- lected should be at such a height that the telescope can later be set up close to it, with the objective at the same height as the selected point. Read the angle of site. This reading will be equal to (300 4- S + E), in which S is the angle of slope of the line of sight, and E is the error in the site adjustment. Before leaving this station, set up a second stake near the telescope and mark on it a point which is at the height of the objective. Now move the telescope to the first stake ; set up and level the instrument with the objective at the height of the point marked on this stake. Lay on the marked point of the second stake and read the site. This angk will be equal to (300 - - S + E). Subtracting one reading from the other we have : (300-fS + E)-- (300 S + E) = 2S ; or one half the difference of the two readings is equal to the angle of slope of the line of sight. Therefore with the cross wires directed upon the marked point of the second stake, center the bubble of the site- level. Now loosen the angle of site locking screw and turn the micro- meter to read (300 S), being careful to keep the bubble centered. Screw up the locking screw. The instrument is now in adjustment. 42 Figure 16 Figure 17 After one telescope has been adjusted, other telescopes, aiming circles and quadrants may be adjusted by merely measuring the site of some distant point. The other telescopes and guns, being in position near the adjusted telescope, are then made to read the proper site when laid upon the distant point. FIELD ARTILLERY RANGE FINDER, 1 METER BASE (BAUSCH & LOME) (Figs. 16, 17, and 18) 93. The instrument and accessories consist of the range finder proper, the tripod mount, the tripod, the adjusting bar, the carrying-case and the storage box. The optical parts of the range finder are embodied in a seamless, steel tube (A) covered with canvas and asbestos, to minimize the effects of the change of temperature. The eyepiece (B) is located in the center of the instrument and is equipped with a focusing device graduated in diopters. A soft rubber eye cap is furnished to protect the observer's eye from shocks and stray light. A ray filter having two sets of glass is operated by a small lever (C) situated to the lower left of the eyepiece housing. The objective openings on the end boxes are opened and closed by means of rotating shutters (D). Buffers (E) are provided on the ends as a protection against shocks. The range finder is of the type known as the fixed base, invert, single coincidence. The magnifying power is 15 ; actual field of view 50 mils ; shortest distance measurable 400 yards. The instrument v/eighs about 20 pounds. Under favorable conditions and with expert operators the average errors are: 1000 yds 5 yds. 2000 yds 15 yds. 3000 yds 30 yds. 4000 yds 55 yds. 5000 yds 90 yds. 6000 yds 130 yds. 7000 yds 175 yds. 8000 yds 225 yds. In practical use under ordinary conditions and with average oper- ators, the errors are three times as great. 94. The tripod mount consists of a spring catch (a) ; clamping lever (N) ; elevation worm case (b) ; elevation worm knob (c) ; worm ^ wheel support (d) ; angle of site micrometer (e) ; angle of site housing 45 1 Figure 18 (f) ; angle of site vial holder (g) ; clamp screw handle (h) ; azimuth worm knob (i) ; azimuth micrometer (j) ; azimuth worm lever (k) ; azimuth scale (m) ; adjusting worm knob (n) ; and the vertical spindle clamping lever (p). The tripod, consisting of spinxHe bushing locking screws (t) ; tripod legs upper (r) ; tripod legs lower (q) ; clamping- wing nuts (w) ; and locking clamp arms (x), is similar to that provided for the B. C. telescope and the aiming circle. CARE AND INSTRUCTIONS. 95. To set up the Range Finder* Set up the tripod as hereto- fore prescribed, take the range finder from its case, holding it with the eyepiece toward the body, hook down. Place the instrument on the support and engage the spring catch (a). The instrument is then firmly seated on the tripod. Remove the protective hood from the eye- piece and the rotating shutters (D) from the objective apertures. Loosen the locking lever so that the range finder may be made horizon- tal, then turn toward the target and clamp the lever. To dismount the range finder the operations are executed in an inverse manner. 96. To Measure a Distance* Focus the eye piece. In very bright light or in thick haze use the amber ray filter in the eyepiece. By means of the clamps and worm knobs of the azimuth mechanism and the worm knob of the elevation mechanism, lay the range finder on the target roughly by looking through the open sight on top of the in- strument. Final adjustment in deflection is made by the adjusting worm knob (n) and in elevation by the elevation worm knob (c). Now, look into the instrument. The field of view (Fig. 20, b) is divided into two parts by a horizontal line. In the lower part the image is erect, in the upper part inverted. By turning the elevation worm knob (c), the images are lined up so that the same points will touch the -dividing line (Fig. 20, c). Now, by turning the measuring roller (M) on the right hand top side of the range finder, the upper image is shifted laterally until the same vertically disposed points of the target are exactly opposite each other (Fig. 20, d). The range is then read on the range scale (H), which is protected by a sliding shutter (Q). In case the target is without prominent vertical features, such as a crest line, the distance is measured by first turning the instrument to a vertical position (Fig. 19). This is accomplished by the clamp scre\v handle (h) on the tripod mount. Final adjustment in deflection is then made by the elevation worm knob (c), and in elevation by the clamping lever (N). The crest, or other horizontal line is then taken as the ebjective. (Fig. 20, e, f). 47 Figure 19 Fig. 20 ADJUSTMENTS (Fig. 20, a to h) 97. Adjustment for Height, The erect and invert images some- tunes do not touch the dividing line with similar points so that one image reaches this line before the other (Fig. 20, a). In this case, lay the range finder on an object having a sharply defined horizontal line or very prominent point, and bring the images of this point exactly oppo- site each other by means of the measuring roller (M). The two images are then brought to the dividing line, the lower image by means of the elevation worm knob (c), and the upper image by means of the halving adjusting roller (J). 98. Adjustment for Range* Three methods are available for ad- j Listing the range finder for range ; the artificial infinity method, using the adjusting bar; the actual infinity method, using the sun, moon, star, or a very prominent distant point ; the known range method, using a point the range to which is known. Of the three, the first is the best .and should habitually be used. 99. By the Adjusting Bar* Set up the range finder; take the ad- justing bar (u, Fig. 18) and place it 100 yards from the instrument, sighting through the peep sight (y) of the adjusting bar and moving it until the range finder appears in the center of the field of view. Set the range scale at infinity by turning the measuring roller (M), then make an observation on the adjusting bar. The right hand, line of the upper image of the adjusting bar and the left hand line of the lower image should now be coincident, in which case the instrument is in ad- justment (Figs. 20, g, h). If not, bring these lines in coincidence by turning the key which fits the square shaft (K), which operates the range correction dial (L). This operation should be repeated at least three times, the reading of the range correction dial being noted each time. Now, set the range correction dial at the mean of the three read- ings. Remove the key. The instrument is now in adjustment. Before using, always note the reading of the range correction dial. 100. By the Actual Infinity Method* This method is in all re- spects the same as the one with the adjusting bar, except for the images. After the instrument is set for infinity, actual coincidence is made as in paragraph 99. 101. By the Known Range Method* Operate the measuring roll- er (M) until the range dial reads the actual distance to the object. After the range finder has been set for this known range, actual coin- cidence is obtained by using the key which operates the range correction dial. 50 Circle, Tripod for A.C. FIELD GLASSES (Fig. 22) 102. The instruments for focusing the eyepieces and for adjusting the interpupillary distance are the same as for the telescope. The two barrels should revolve easily about the central pivot and clamp in any position of the interpupillary scale. After being once adjusted, the field glasses should fit into the case without being changed. Carrying strap, button strap and rain shield should always be part of the equipment. Amber shades and camels hair brush should be car- ried in the case for use. The vertical scale (Fig. 22) in the Type EE Field Glass represents the infantry range scale and does not apply to Field Artillery. Compass should always be securely clamped except when in use. THE BRACKET FUZE SETTER, MODEL 1905 M. (Figs. 23 and 24) 103. The bracket fuze setter is attached to the rear end of the fuze- setter bracket on the caisson. It consists of the following principal parts : Base, housing, corrector-worm case, guide, range and corrector worms, rings, and scales. The corrector scale reads from to 60, numbered every 10 points, 30 being the normal or mean arbitrary point. The range ring is gradu- ated to 6400 yards, numbered every 500 yards, least reading 50 yards. These rings are graduated for the F. A. fuze on one side and for the Ehrhardt fuze on the other. Care should be taken that the proper side is up when firing the two different kinds of shrapnel. THE HAND FUZE SETTER, MODEL 1912. (Figs. 23 and 24) 104. The hand fuze setter is provided for the same purpose as the bracket fuze setter, and is intended to supplement the latter. One hand fuze setter is issued in a leather case and is carried in the trail box oi each gun. It is intended for the use in case the bracket fuze setter should become disabled, or in case the gun should for any reason be separated from its caissons. The principal parts are the case, the range index mechanism, range mechanism, corrector mechanism, and guide plate. 52 Fig. 22 Inter pupillary A Scale Eye-piece - Diopter Scale- -Eye-glass _ -Porro Prism 1 -Objective L_2o Bracket Fuze Seller Fig. 23 -Pointer Arm and Plate(Corrector Index) -Kcrnge ffumptng Holts a Hand Fuze Seller. --Case Base. -Moling Pin Notch, - Range Ring Corner r The corrector scale and the range ring graduations are the same as for the bracket fuze setter. The point attached to the corrector ring is so fixed that it will coincide with the graduated line on the closing cape of the fuze when the latter is correctly set. The fuze setter must therefore be turned until it is stopped and this coincidence is observed, otherwise the setting of the fuze is incomplete. AMMUNITION (Fig. 25) 105. Fixed ammunition is used in the 3-inch field guns, and is made 'up with either common shrapnel, high explosive shrapnel, or common steel shell. The rounds as made up vary in length with the type of pro- jectile used. The ammunition chests of the battery are of sufficient size to take any one of the rounds furnished, so that the number of each kind to be carried is a matter for regulation by proper authority. Each round is issued with projectile filled and fuzed. The weight of the pro- jectile is* 15 pounds, and the total weight of one round is 18.75 pounds. The components of one round are the cartridge case with primer, the powder charge, igniter, projectile, and fuze. 106. The cartridge case* The cartridge case is a solid drawn- brass case 10.8 inches long; itjias a capacity of 66.5 cubic inches, and weighs, with primer, 2.25 pounds. A circular groove is cut in the base of the cartridge case and the groove is painted red for high explosive shrapnel, yellow for common shrapnel, and black for high explosive shell 107. The primer. The percussion primer, known as the "110-grain percussion primer," contains an igniting charge of 110 grains of black powder in addition to the essential elements of a percussion primer. The purpose of the black powder is to insure the ignition of the smoke- less powder charge in cartridge case. 108. The powder charge* The powder is a nitrocellulose powder composed of multiperf orated (7 perforations) cylindrical grains, each 0.35 inch long and 0.195 inch in diameter. The charge varies slightly for different lots of powder, but is approximately 24 ounces. The charge gives a muzzle velocity for shrapnel of 1,700 feet per second (1600 f/s for shell) with a maximum pressure in the bore not exceed- ing 33,000 pounds per square inch. At the front end of the cartridge case there is an igniter of black powder weighing about 54 oz. which assists in the uniform ignition of the smokeless powder charge. 56 109. The projectiles* All projectiles have a copper rotating band 1.2 inches from the base. This band engages in the rifling of the bore of the piece, and gives the projectile a rapid rotation about its long axis during flight. This causes it to travel straight, point on, without tumbling. 110. Common shrapnel* The common shrapnel is a base-charged shrapnel fitted with a combination fuze. The case is of steel with solid base. The shrapnel filling is composed of 252 balls, each approximately 167 grains in weight (42 to the pound). The balls are approximately 0.5 inch in diameter. The balls are poured around a central tube and rest upon a steel diaphragm, the interstices containing a smoke-produc- ing matrix. The bursting charge consisting of 2^4 oz. of black powder is in the base and is covered by the diaphragm which supports the cen- tral tube, affording a conduit to the flame leading from the fuze to the bursting charge. In action the case is not ruptured upon the explosion of the burst- ing charge ; the head is stripped and the balls are shot out of the case with an increase of velocity of 'about 274 feet per second. The re- maining velocity of the shrapnel at 6,500 yards is approximately 724 feet per second and the time of flight 22 seconds, so that at that extreme range, with the increase of velocity due to the bursting charge, this shrapnel with 21-second fuze will be effective. The weight of the shrapnel with fuze is 15 pounds. 111. Shrapnel is a projectile containing a great number of hardened steel balls, each approximately J^ inch in diameter, which may be pro- jected from a point in the air (called the point of burst) close to but short of the target. Each ball is capable of killing a man or horse at a distance up to 250 or 300 yards from the point of burst. Taken collec- tively, the paths of these balls form a cone, called the cone of dispersion. The ground section of this cone is elliptical in shape with its longer axis approximately in the plane of fire. At mid-ranges when burst at normal height of burst (H.B.=3 mils), the dimensions of this area are approximately 20 yards wide by 250 yards deep. These dimensions will however vary with the -angle of fall, the height of burst, the slope of the ground at the target, and the relation between the linear and the rotational velocities of the shrapnel at instant of burst in the air. A 3- mil H.B. is chosen because this gives an average density of 1 hit per square yard of vertical target area. An infantry skirmisher (Standing) with his interval occupies approximately 1 square yard. Shrapnel has very little effect upon material objects. It is very effective against personnel not protected by cover, or to search an area ' which is known to be occupied, or which must be traversed, by hostile troops. 57 Cove* Fig, 25 J3dse (Joi-et* Groove anrt calkiny wire. r ftolaling and. r -3tecl Shell. r __ .--Base Detonating Fuze, ifyedium Caliber i* ]C*apacify J3- 12 oz. Explosive* J}. I I --- Lubricafing and Crimping Grooves. Steel Black Powder: -Cenfrnl Tu&e. Bourrelet. \-SteelKeacf. Common Shrapnel. Groove. * Percuss? ion Cap. ; Compressed fbivderr TinFott. /.Wad. Cover Crimping Groove. ' i Capacity 6 6.5 cu. ins Xiah Explosive Shrapnel, 112. Ehrhardt High-Explosive ShrapneL The Ehrhardt high-ex- plosive shrapnel is fitted with a combination fuze and a high explosive head. The case is drawn steel with solid base. The shrapnel filling is composed of 285 balls, each approximately 138 grains in weight (50 to the pound). The balls are poured around the central tube and rest upon the steel diaphragm, the interstices containing a matrix of high explosive. In time action (burst in air), the case is not ruptured upon the explosion of the bursting charge, but the head is forced out and the balls are shot out of the case with an increase of velocity of from 250 to 300 feet per second. In the meantime the head continues its flight, detona- ting on impact. If the fuze be set at "safety" or for a time greater than the actual time of flight, this shrapnel may be used in lieu of high-explosive shell. Upon impact a high-explosive shrapnel is detonated by means of the percussion element of the combination fuze, the head being detonated first, which detonation causes the sympathetic detonation of high- explosive matrix surrounding the balls. 113. Common Steel ShelL This steel shell is high-explosive and fitted with a base detonating fuze. The case is hollow and made of forged steel. It is provided with an ogival head. The steel shell con- tains a bursting charge of 13.12 ounces of Explosive D. The weight of the shell with bursting charge and fuze is 15 pounds. The shell is' always issued filled and fuzed. This shell bursts on impact and with great force exerted in all directions. It is a powerful instrument for the destruction of material objects such as guns, intrenchments, houses, stone walls, etc. The effect, however, is very local. FUZES 114. Frankford Arsenal Combination Fuzes* These fuzes are point fuzes with combination time and percussion elements for use with common shrapnel. They are of the 'type known as the ring or "dial" fuze, in which the time train is set by turning a graduated ring which carries part of the train. These fuzes may be reset as often as desired. 115. Ehrhardt Combination Fuze for High Explosive ShrapneL This fuze is similar to the Frankford Arsenla Combination time and percussion fuze but in addition contains a high explosive head and de- tonating element. Due to this arrangement, both the projectile and the high explosive head have a high explosive shell effect when striking on impact. 59 116. The Service Base Detonating Fuze. The details of the de- tonating fuze and the composition of the detonator are kept secret. A detonating fuze is necessary in order to produce a higher order of ex- plosion by causing an instantaneous conversion of the high explosive compound called "Explosive D" with which the shell is charged. If an ordinary percussion fuze were used only an ordinary explosion would be produced, as in the explosion of black powder. BLANK AMMUNITION. 117. Preparation of Blank Metallic Ammunition* Blank metallic ammunition will always be assembled under the personal supervision of a commissioned officer, who will be held responsible that it is prepared in the manner prescribed. (G. O. 9, War Dept., Jan. 11, 1908;) For this purpose there are issued blank-cartridge cases, black powder, in bulk, tight-fitting felt wads, rubberine, or other quick-drying paint, primers, etc. 118. Before assembling, the cartridge cases should be carefully in- spected to see that they are in sound condition and thoroughly clean and dry. They should also be tested by trying them in the gun, to deter- mine whether they have become deformed. Any cases that do not readily enter the chamber in the gun or that are otherwise seriously de formed should be laid aside for resizing. After inspecting the cart- ridge cases the blank ammunition should be prepared as follows : (a) Insert the primers with the primer-inserting press. (b) Pour into the cartridge case the proper weight of black pow- der and shake it down well. (c) Insert the felt wad and press it down hard until it rests squarely on the powder charge. (d) Give the upper surface of the felt wad and the inside of the cartridge case just above the wad a good coat of the rubberine or other quick-drying paint furnished for the purpose, using a brush, and allow the case to stand until this coat is dry. Then apply another coat of rub- berine paint in a similar manner. The object of using rubberine paint, which is strongly adhesive, is to thoroughly seal the joint between the wad and the case to prevent any powder grains from leaking out, and at the same time to firmly hold the wad in place. 119. The Reloading and Cleaning Outfit. This outfit consists of the following parts, and is furnished to each battery : 60 Primer-inserting press, small Hammer Bushing Case holder Powder measure, saluting Case-holder stand Decapping tool, with guide Storage chest Cleaning brush The bushing is used in the primer-inserting press for the inser- tion of new primers. The decapping tool and case holder and stand are used for re- moving exploded primers from the cartridge cases. A light blow on the rod with a piece of wood or the bronze hammer generally removes the primer. A powder measure to suit the saluting charge for the gun is fur- nished, and when level full holds the required charge. The cleaning brush is furnished for cleaning the cartridge cases after they have been used and should be ordered to suit the size of case for which intended. 120. Care of Cartridge Cases* As soon after firing as practicable the exploded primers should be removed from the cartridge case by means of the decapping tools furnished with the reloading outfit. The case should then be thoroughly washed in a strong solution of soft soap and soda to remove all powder residue. It should then be thoroughly dried. 121. If the cartridge cases are carefully cleaned and washed imme- diately after firing, not only will less labor be required but the life of the cartridge case will be greatly prolonged. A good solution for washing cartridge cases may be prepared by using ingredients in the following proportions : 1 gallon of water, 2^2 ounces of soft soap, 5% ounces soda. The mixture should be boiled and stirred until the ingredients are entirely dissolved. In washing cartridge cases this solution should be used hot and in sufficient quantity to completely immerse the cases. Neither acids nor solutions of acids will be used for cleaning cart- ridge cases. Precautions to be Observed with Fixed Ammunition 122. (a) Do not unnecessarily expose ammunition to the sun or load it into a warm gun before time for firing ; if this is done, erratic shoot- ing will result. (b) Handle carefully, otherwise cartridges may become deformed and cause jams. (c) Never use force or any implements on the base of the cart- ridge in loading. 61 (d) See that fuzes set at safety or are provided with waterproof brass cover for transport. (e) Do not fire ammunition which has been under water with the waterproof brass cover removed. (f) Both service and blank ammunition should never be carried in the battery at the same time. If conditions are such that both may be used in exercises, only one kind should be in the firing battery; the other should be under lock and key outside the firing position. (g) Misfires and hangfires are of exceedingly rare occurrence, in case of a failure to fire, the firing handle should be pulled again in order to snap the trigger. If this fails to fire, the breech should not be opened until after the expiration of at least one minute, when the round or cartridge should be removed and placed to one side. Defec- tive ammunition, cartridges and primers should be reported. With Blank Ammunition 123. Firing with blank ammunition will be greatly facilitated by a careful observance of the following : (a) Before firing, a careful examination should be made of the assembled rounds to see that the felt wads have not become displaced or the cartridge cases dented or deformed by careless handling. If the cartridge cases have been properly resized and are clean, no difficulty should be experienced in inserting them in the gun, provided the cham- ber of the latter is clean, f he continued insertion of cartridge cases that are not clean causes an accumulation in the gun chamber which may make the insertion of subsequent rounds difficult or impossible. (b) In firing blank ammunition the gun chamber will be sponged after each round with a damp sponge, to extinguish sparks and remove powder residue resulting from the previous round, before the insertion of another round. jflB (c) Care will be taken to see that the sponges are not worn and that they thoroughly fit the chamber. The interval between rounds in firing blank ammunition should be sufficient to allow thorough sponging of the chamber and examination to ascertain that all sparks have been extinguished. (d) Wads for the preparation of blank metallic ammunition are made to tightly fit in the cartridge case. No wads should be used that are not a tight fit in the case. (e) Before firing a salute with blank metallic ammunition all die- cartridges to be used should be inserted in the gun to ascertain if they will fit. A few rounds in addition to the required number should tie 62 prepared for use in case of misfires. Lightly oiling the outside of cart- ridge cases just before use will facilitate their insertion and extraction. (f) Smokeless powder must not be used for blank charges. (g) Use the small primer-inserting press for inserting primers in cartridge cases and the decapping tools provided for removing old p rimers. (h) The same precautions concerning misfires and hangfires should be observed as with service ammunition. Defective cartridges ;;nd primers should be reported at once. (i) Saluting primers are issued in hermetically sealed boxes, 25 1 o a box. The boxes should not be opened nor the cartridge cases made np and primed until shortly before they are required. Cartridge cases should then be made up in lots of 25. TOOLS AND ACCESSORIES 124. In the repair of all equipment, it is literally true that "a stitch in time saves nine" and that a timely repair will save the entire article. 125. Tool Kits will be kept complete and serviceable; edges of cold chisels free from nicks ; drifts and punches properly shaped imme- diately after using; and files kept clean. To prevent unscrewing, copper wire is used to lash nuts and other threaded parts which are not secured by split pins. 126. Contents of Leather Pouch for Spare Parts (carried in Trail Box: For Breech-block 3 Range ring screws 50 Split pins 1 Stop pin screw 1 Block latch and spring For Bracket Fuze Setter t Firing pin and spring 1 Corrector scale screw 1 Firing pin sleeve 3 Guide screws :> Handy oilers, 5-16 inch 4 Housing screws & split washers 1 Hinge pin catch 1 Knob washer 1 Lever latch spring 1 Range worm crank & knob 1 Locking bolt, nut and pin taper pin 1 Locking bolt spring 1 Range worm crank handle 2 Oil hole covers with screws 2 Range ring screws 1 Pallet pin 3 Split pins (0.125) 1 Sear 1 Spring and spring cover with 2 Trigger shaft detent screw For Hand Fuze Setter 2 Stop pins with rivets :' Corrector scale screws For Cylinder 1 Guide plate lock screw 1 Drain-plug, cylinder 2 Index bar screws 1 Elevating & traversing lock 1 Index plunger and spring spring 2 Oil hole screws 1 Filling plug (piston rod) 1 Range Index 5 Rings Garlock packing, ->4 in. 127. Special Wrenches, Spanners, other tools and accessories, will be used only for the purposes for which they are intended. This pur- }>o. v , Vertical Lateral ge ' Displacement. Displacement, right. 100 y 2 yard T 4 yard 150 IK yards V 2 yard 200 3 yards 1 yard 250 5 yards 2 yards 91 (f) The striking energy of the bullet is sufficiently great to surely disable a man by causing a dangerous wound at all ranges up to 500 yards. (g) The pistol has been fired by experts at 25 yards, aimed fire, at the rate of 21 shots (3 magazines) in 30 seconds. Such rapidity is, however, not necessary or desirable in service firing. Accuracy is always the first consideration. Precautions 1. Whenever the pistol is taken out of or returned to the arm rack, also both before and after drill or other exercise with the pistol, remove the magazine and see that it is empty. Then draw back the slide which will eject any cartridge in the chamber. Finally look through the bore to see that the pistol is unloaded and the bore not obstructed by a plug or wad. Replace all parts, come to raise pistol and lower hammer. 2. Never place the trigger finger within the trigger guard until it is intended to fire and the pistol is pointed toward the target. 3. Do not carry the pistol in the holster with the hammer cocked and the safety lock on, except in an emergency. 4. Always press the trigger with the forefinger. 5. After each shot relieve the pressure on the trigger so that the sear may re-engage. 6. When inserting the magazine be sure that it engages the maga- zine catch. Never insert the magazine by striking it smartly ; -always apply a continuous push. 7. The pistol must be kept clean, free from rust and properly oiled. 8. Never disassemble the receiver except by permission of an officer. 9. In disassembling the receiver be sure that (a) the disconnector and sear are properly assembled. (b) that the hammer is not snapped when the pistol is partially as- sembled. (c) that the stocks are not removed. (d) that no hammer is used either in assembling or disassembling. 92 INDEX Par. Accessories and Tools 124134, 207 Adjustment of Sights and quadrant 7580, 207 Aiming Circle, adjustment of 83, 91, 92 care of 63-65, 87-90 description 86 use of .-; 87 ~ 90 Aluminum Equipment, care and cleaning of 198 Ammunition, blank, preparation of 117, 118 precautions 123 Ammunition, fixed 105116 precaution in use of 122 marking of ' 106 Ammunition carrier 13, 16 Ammunition carrier, to remove 61 Apron, for caisson 32-34 Apron latch, to remove . 61 for caisson 34 for gun carriage 26 Automatic pistol, care and cleaning of 194, 195, 208, 210, 217 Axes 130 Axle, for caisson % . 34 for gun carriage 13, 14, 26 for limber 27, 30 Axle seats 13, 26 to remove ! 61 i Battery Wagon, care of 201 B. C. Telescope, adjustment 83, 91, 92 care of 63-65, 83-85 description 81, 82 use of 8385 Belts, field (web), care of 200, 218 Bits, care of 193 Blacksmith's Tools 209 Block and Tackle 209 Blankets, horse, care of 199 Block carrier, for M '05 gun 10 Borax 146 Brake, to adj ust 56 to assemble 61 to remove 61 Brake beam, to dismount 61 Brake lever, to dismount 61 Brake shoe, to dismount 61 Breech block, M '05 9 Breech mechanism, to clean 127, 162, 205 description 11 nomenclature 12 action of 10 to dismantle and assemble 35 Breech mechanism, spare 209 Brown enamel primer 152 Bucket holder 28 Buckets, canvas 131, 207 Caisson, description 31, 32 nomenclature 34 weights and dimensions cc Canteens 219 93 Canvas buckets 131, 20? Carpenter's chest and tools 209 Care and preservation of material 135171 general instructions 168171 Carriage, gun, action of , 24 description of 23 nomenclature 26 principal parts 13 weights and dimensions 25 Carriage, parts of, care in assembling and disassembling 168-17 L- care of, and cleaning 205 painting 207 Cartridge case, fixed ammunition lor. Cartridge case, blank ammunition, care of 120, 121 Cartridge holes, in limber and caisson 28 Cases, sights and quadrant 206 Chest body, for caisson 32 for limber 28 Chest for. cleaning materials and small stores 200 spare sights 209 miscellaneous spare parts . . " 209 Cleaning leather equipment 175192 Cleaning and care of materiel 158167 Cleaning material for field artillery 136157 Cleaning Schedule, for F. A. materiel and accessories 203209 ior Arms, equipments and equipage 210221 daily 203, 204 special 205-209 Clock oil 140 Cloth (web) equipment ' 200202 Clothing, field service ! 211 Coal oil 28, 143 Collars, steel 1.7?, cleaning and care of 19.') Cooking utensils, field '221 Counter-recoil buffer 20, 21 to remove 46 Counter-recoil springs, to clean 164, 206, 208 Counter-recoil springs, double 2022 to assemble 48, 49, 168 to dismount 47, 49, 168 Counter-recoil springs, single 2022 to assemble 49, 168 to dismount 47, 49, 168 Cradle, care of 208 complete, description 1823 contents 19 to assemble 168 to dismount 60, 168 Cradle head, front 21 rear 19 Cradle mechanism, action during firing 24 Cradle pintle 18 Curry comb 215 Cylinder, to assemble 41, 42, 168 care and cleaning 42, 206, 208 to disassemble and clean 1 5H description 20 to dismount 40, 168 to fill TStt to empty 1 ''><) Cylinder end stud and nut 19. 49 Cylinder oil, to clean 161 94 Dismounting and assembling parts of mechanism 35 (51 Double tree 208 Dust guard ' Elevating bevel gear, to dismount 53 Elevating bevel pinion, to dismount 53 Elevating gear bracket, to dismount 54 Elevating mechanism and gear, description '10 to assemble 55, 168 to clean 165, 205-208 Elevating screws, to dismount 52, 168 Elevating screw cover 52 'Engine Oil No. 1 139 Farrier's pocket case 21("> Field Glasses, care of 63-65, 102 Field Kit 213 Field Range 221 Fire Control equipment 207 Firing, precautions during 170 Firing-lock case 11 Firing mechanism, M. '05 nomenclature 12 to dismantle and to assemble 36 action of 11 First aid pouch 21? Forge ". 209 Forge limber 209 Fork 211 Fuzes, kinds 114-116 safety of 122 Fuze, base detonating 116 Fuze, Ehrhardt combination for high explosive shrapnel 115 Fuze, F. A. combination, M. '07 114 Fuze setter, bracket, M. '05 103 Fuze setter, hand, M. '12 104 Fuze setters, care of 207 Gland, adjustment of 43, 44 location 20 Glasses, Field, care of 63-65, 102 Grip straps 28 Grindstone 209 Guide rails, to clean 165, 205 Gun clips, to clean 205 Gun. M. '05, description 6 nomenclature 8 to clean the bore 162 to dismount 38, 169 to mount 39, 168 weights and dimensions 7 Gun slides, location 8 to clean 165, 205 Hammers, use of 128 Handspike, trail 15 Harness, list of 172-174 F. A. nomenclature 174 care and cleaning of 175188 storage of 189-192 Hatchets, care of 130 Haversacks 218 Horse brush 2 1 ."> Horseshoer's tools 209 Hub cap, to remove :>7 95 Hub liner, to remove 59 Hydroline, use of 28, 138 to clean 161 Instructions, care of materiel, general 168171 care of harness and leather equipment 175192 care of automatic pistol, sub-calibre cartridge, etc 194196 ' care of other metal equipment 197, 198 care of blankets, and cloth equipment 199202 Jack screw 209 Knife 2)2 Lanterns 132, 207 Lavaline x . 147 Leather equipment, care of 175192 Leather, russet, care of 175192 Leather, reasons for oiling 182186 Leather and leather equipment, storage of 189192 Leather straps, care of 200, 208, 217 Light slushing oil 145 Limber, description 27, 28 nomenclature 30 weights and dimensions 29 Lunette 15, 32 care of 208 Lubricating oil 28, 139 Lye 148 Materiel, cleaning and preserving 136157 Materiel, detailed information in other pamphlets "> General information for care and maintenance of 168171 Instruction in, object of 1, 4 Metal equipment, care of 197, 198 Meat can, care of 212 Misfires and hangfires 122 Napthalene 149 Neat's foot oil 144, 176, 178 Observing Instruments and Sights, general instructions 6.'J 65 disassembling, instructions 66 list of 62 Oils for artillery materiel, and their use 136145 Hydroline 138 Lubricating 139 Clock 140 Vaseline 141 Sperm 142 Engine, No. 1 1 :Ji Coal 143 Neat's foot 144, 176, 178 Light slushing 105 Oil holes, cleaned 205 Paint, rubberine 1^1 Painting artillery materiel '- ( '^ Panoramic sight M. '15 71, 72, 74 care of 72, 74, 207 adjustment of 78 Paulins 28, 32, 133 Picket ropes 134, 207 Picks 1-" 96 Pick mattocks 130 Pintles 27; 32, 207 Piston rod and head 21 care of 207, 208 to remove 45 Piston rod nut 21 Pliers, wire cutting 129 Pistol, automatic 194, 195, 208-210 cleaning kit 209 holster, cleaning of 217 Pole, qire of 208 to remove and to replace 50 Pole spare, care of 208 to remove and to replace 50 Polish, Gibson's soap 150 Pouch, for spare parts 12G Powder charge 108 Precautions, with materiel 170, 171 With fixed ammunition 122 With blank ammunition 123 Primer, brown enamel paint 152 Primer, 110 grain percussion ^ . . 107 Projectiles, description of 105, 109-116 Quadrant, range, care of 73, 74, 207 description 73 when in adj ustment 76 field adjustment of 80 Range Finder, adjustments 97101 care of 6365, 95, 96 description 93, 94 use of -. 95, 96 Range quadrant, description 73, 74 care of 73, 207 field adjustment 80 Rear clip, function 18 Recoil indicator, to remove 37 Recoil-springs, to clean 164 Recoil mechanism, action of, during firing 24 Reloading and cleaning outfit 119 Retaining ring 19, 23 Road brake, care of 207 Road brake, Battery and Store wagon 209 Road brake, to adjust 56 to dismount 61 to remove 61 Rocker, description 13 to dismount 61 Rubberine, paint 151 Saddlebags, care of 217 Saddle equipment, care of 180192 Saddle blankets, care and cleaning of 199 Saddler's chest and tools 209 Saddle soaps . 179 Sal soda 153 Shell, common steel, description and action of 113 Shelter-halves 218 Shank socket, care of 74, 207 Shields, to remove 61 Shovels 130 97 Shrapnel, common, description and action of 110 use of Ill Shrapnel, Ehrhardt high explosive, description and action of 112 Sights, list of G7 when in adj ustment 75 Sight and Observing Instruments, general instructions 6365 disassembling, instructions 66 list of 62 Sight, line 68 Sight, front 69, 208 Sight, rear, description 69, 70 nomenclature 70 care of 74, 205-208 adjustment of : . 77, 79 Sight, panoramic, description 71, 72 care of 72, 74, 207 adjustment of 77, 78 Sight shank, care of 74 Sights, spare 209 Sights, examined 206 care of 168 Signal equipment 206 Single-tree 208 Soaps, castile 155, 177 H. & H 154, 199, 201 Gibson's Polish 150 Saddle, Hollingshead's 156, 179 Spanner wrenches 127 Spare parts, contents and pouch for 126, 208 Spoon ' 272 Spur straps 217 Sperm oil 142 Split pins 128 Spring compressor , 47, 48, 49, 50 Spring support 23 Stuffing box, to pack 42 Store Wagon 209 Sub-caliber cartridge, care and cleaning of 196 Surplus Kit 214 Swabbing solution for pistols, etc 157 Telescope. B. C. adjustment 83, 01. 92 care of . . 63-65, 83-85 description 81, 82 use of 83-85 Tent, shelter half 218 Tentage :.":< ) Tin cup 212 Tools and accessories 124-134 Tool kit 125 Tools for gun and carriage 1 '- < Tools for limber > Trail, description of i-~ to dismount 61 Traversing mechanism, description 17 to dismount and assemble 58, 168 to clean 166. 205, 207 Uniform, field Ml Vaseline 141 Vise 209 98 Web equipment, care of 200-202 Wheels, description 14, 28 to clean and lubricate 167, 169, 205-208 to remove 58 care of Hi'i Wheels, new, care of , 200 Wheel fastening 14, 2S to remove ">s Wheels, spare . . . :><)<> Wheels, painting of 209 Wire, copper 125 Wrenches . . 127 99 YC M308 UNIVERSITY OF CALIFORNIA LIBRARY