32 



AKMY OF THE UNITED STATES. 



Total length 180 inches. 



Length of calibre of bore 156 



Length of ellipsoidal chamber 9 



Total length of bore 165 



Maximum exterior diameter 48 



Distance between rimbases 48 



Diameter at muzzle 25 



Thickness of metal behind the chamber. 25 

 Thickness at junction of bore with cham- 

 ber 16i 



Thickness at muzzle 5 



Diameter of shell 14.9 



Weight of gun 49,100 Ibs. 



Weight of shell 320 " 



Bursting charge 17 " 



Tliis gun has been fired several times at For- 

 tress Monroe, and is manoeuvred with great 

 facility, managed by one sergeant and 6 ne- 

 groes. The mean range at 6 elevation, of 

 ten shots, was 1,936 yards, and the mean lat- 

 eral deviation 2.2 yards : the charge was 35 

 Ibs. of 0.6-inoh grain powder, and the time of 

 flight 7 seconds. At 10 elevation, with 40 

 Ibs. of powder, the range was 2,700 yards, and 

 time of flight 11.48 seconds. At 28 35' ele- 

 vation, the range was 5,730 yards, and time 

 of flight 27 seconds, with very slight lateral 

 deviation, as appeared through a telescope at- 

 tached to one of the trunnions. 



Parrott Gun, This arm, named for its maker, 

 Mr. R. P. Parrott, agent of the West Point 

 Foundry, at Cold Spring, is perhaps the most 

 effective for its weight as a field-piece and siege 

 gun. The plan of its construction is the same 

 in principle as was proposed by M. Thierry, of 

 France, in 1834, and afterwards somewhat 

 modified by other inventors, as Prof. Treadwell, 

 of Cambridge, Mass., in 1845, Capt. Blakely, 

 of England, in 1855, and others. It first 

 came to be known in 1860, when the State of 

 Virginia was supplied with twelve 10-pound- 

 ers, and 16 more guns were made in the fall of 

 the same year on an order from the State of 

 Georgia. These, however, were not delivered. 

 During the year 1861 there have been made at 

 this establishment, for the U. S. Government, 

 the following pieces : 



No. of pro- 

 Sizes. No. of pieces, jectiles. 



10-pounders 292 71,000 



20-pounders 153 25,000 



30-pounders 94 22,000 



100-pounders 5 1,000 



There were also made 115 smooth-bore guns, 

 as 8 and 10-inch columbiads and Dahlgren navy 

 guns, with 30,000 projectiles for these. The 

 Parrott guns are manufactured of the strongest 

 cast-iron, all of which is tested before use, and 

 is required to bear a pressure of 30,000 Ibs. 

 upon a square inch. They are cast upright, 

 with the breech down, which portion is thus 

 rendered most dense by the pressure of the 

 liquid iron above. After the pieces have been 

 turned and bored, the breech is strengthened 

 by a broad ring of wrought iron, which is put 

 over it hot, and thus shrunk on so as to appear 

 as of one piece with the gun. This ring is pre- 

 pared from a bar of iron, 4 inches square and 

 of any required length, which is brought to a 



high heat, and is then wrapped around a cylin- 

 der of the size of the gun in a continuous coil, 

 the spirals of which are then welded together 

 by hammering. By this method the guns are 

 made of a comparatively cheap material, and 

 by the economical method of casting, while the 

 wrapping of wrought iron secures the addition- 

 al strength of this material at that portion of 

 the gun only where extreme strength is re- 

 quired. To^obtain the same strength with cast 

 iron alone, would greatly increase the thick- 

 ness and weight of the breech. The Parrott 

 gun weighing 1,100 Ibs., is considered stronger 

 than a columbiad or Dahlgren of the same 

 calibre weighing 1,500 Ibs. The proportional 

 weight of the powder used to that of the pro- 

 jectile is only r V, while in other heavy guns it 

 is \ or more. In trials made at Cold Spring 

 with a 100-pounder Parrott gun, using 10 Ibs. 

 of powder, a projectile was thrown beyond 

 6,200 yards, the elevation being 20 ; while a 

 columbiad with the same elevation, and using 

 18 Ibs. of powder, threw its projectile only 

 3.883 yards. 



The original projectile for the Parrott gun, 

 known as the Reed projectile, was made with a 

 cast-iron body, furnished with a wrought-iron 

 cup-shaped base opening towards the powder, 

 and secured into the base of the body by being 

 cast in with it. In the explosion the sides of 

 this, being of a malleable material, were pressed 

 out, filling the grooves of the bore. This is 

 now replaced by a projectile entirely of cast 

 iron, around the base of which is a depression 

 of V-shaped section in which a brass ring ia 

 loosely fitted. This is forced by the powder, 

 as it explodes, into the grooves, causing the 

 projectile to follow their curve. 



Whitworth Gun. In June, 1861, there ar- 

 rived in New York, from England, a battery 

 of six Whitworth guns, with 3,000 rounds of 

 ammunition, sent from England as a present to 

 the United States Government, from patriotic 

 Americans in Europe. These guns, which rank 

 among the most efficient in England, are breech- 

 loading, though they may also be loaded from 

 the muzzle. Instead of being rifled the bore 

 is hexagonal, with the angles of the hexagon 

 rounded off, and the effect of rifling is produced 

 by the twist of the sides of the hexagon. The 

 guns are made of what is called homogeneous 

 iron, which is wrought iron melted and cast in 

 moulds, which thus assumes a homogeneous 

 texture and the greatest strength. The projec- 

 tile is hexagonal, accurately fitted to the bore 

 of the gun with the same twist. It is made of 

 cast iron, unless intended for penetrating hard 

 bodies, as wrought-iron plates, when it is made 

 of homogeneous iron and with a flat head. The 

 charge is ^ the weight of the projectile, and is 

 placed in the bore in a tin cartridge, which 

 remains behind when the gun is fired, and is 

 then removed. The guns sent to the Uni'ed 

 States are 12-pounders, measuring 7 feet 9 

 inches in length, with the major axis of the 

 bore 3.1 inches, and minor axis 2.8 inches, 



