462 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



for the escape of the smoke, a very large number of barrels being proved 

 at once. 



About one per cent, of the barrels burst under this trial, although under the 

 old process of welding there was a loss of nearly two per cent., or one in sixty. 



There are forty-nine pieces used in making up a musket, which have to 

 be formed and finished separately; only two of these, the sight and cone- 

 seat, are permanently attached to any other part, so that the musket can, 

 at any time, be separated into forty-seven parts, bj^ simply turning screws 

 and oper;ing springs. Most of these parts are struck in dies, and then 

 finished by milling and filing. The process of this manufacture is called 

 swaging — the forming of irregular shapes in iron by means of dies, one of 

 which is inserted in an anvil in a cavity made for the purpose, and the 

 other placed above it, in a trip hammer, or in a machine operated in a man- 

 ner analogous to that of a pile-driver, called a drop. Cavities are cut in 

 the faces of the dies, so that, when they are brought together with the end 

 of a flat bar of iron, out of which the article is to be formed, inserted be- 

 tween them, the iron is made to assume the form of the cavities, by means 

 of blows of the trip-hammer, or of the drop, upon the upper die. About 

 one hundred and fifty operations upon the various pieces used in the con- 

 struction of the musket are performed by those dies. Some of the pieces 

 are struck out by one operation of the drop, while others, as the butt-plate, 

 require as many as three, and others a still larger number. The hammer 

 is first forged and then put twice through the drop. Four men are kept 

 constantly at work forging hammers in the rough, while but two are re- 

 quired to put them through the two operations under the swaging-machine. 

 Sometimes, however, the work presses upon the droppers, and they have 

 the alternative either to work double time — that is, night and day — or to 

 allow other hands to work with them; and as they work by the piece and 

 are anxious to earn as much as possible each month, they will frequently 

 work night and day for several consecutive days. I have known instances 

 where workmen have worked from Monday until Thursday, night and day, 

 without any intermission, excepting the hour and a half at the morning 

 change of hands, one hour at noon, one at tea-time, and half an hour at 

 midnight — four hours out of the twenty-four. By this means they will 

 sometimes earn as much as one hundred and fifty dollars per month, although 

 this would be an extraordinary case. The average pay in the di'opping- 

 department is about three dollars per day. 



There are twenty-four simple and seven compound dropping-machines in 

 constant operation. Some of the pieces are pressed into shape under these 

 drops when cold — this being the case with the triggers, which were found 

 to use up the dies too rapidly when they were swaged while heated; but, 

 as a general rule, the swaging is done while the piece is at a red or white 

 heat. The operations of the various dropping-machines are exceedingly 

 interesting, and the amount of labor ihey save is perfectly marvellous, 



A large number of men are kept constantly at work making dies for the 

 various pieces required. 



When the pieces come out of the swaging-machines, they have more or 

 less of surplus metal about them, which is cut off or trimmed by passing 

 them through machines designed for this purpose. 



