MECHANICS AND USEFUL ARTS. 51 



regular moving power, the speed of the hammer could not be increased 

 or decreased suddenly at will. The new invention consists of a loose 

 driving belt so loose that when it is not tightened by bearing against 

 it the driving drum has no action upon it. A pulley is attached to a 

 compound lever half way between the drum and the pulley where the 

 power is applied to the hammer, and, by acting upon the lever, the 

 pulley presses upon the belt, until it is so far tightened as to drive the 

 hammer at the utmost speed of the drum. When a smaller speed is 

 required, the lever is partially released, allowing the belt to slip ; and 

 in this manner, by increasing or diminishing the tension of the belt, 

 any required speed is attained. The result of this simple and beauti- 

 ful invention is that a thousand tilt-hammers, if necessary, may be 

 driven by one water-wheel, or by a steam-engine. Springfield Repub- 

 lican. 



IMPROVED SPIKE MACHINE. 



MR. MARK Isox, of Georgia, has patented an improved method for 

 making spikes and nails by machinery. The invention is different from 

 the roller spike machines and the vertical reciprocating cutting nail 

 machines. There is a horizontal table, nearly the form, of the segment 

 of a circle, having a hollow space within it, in which works a revolving 

 cam on a shaft concentric to the table. The iron plate to be made into 

 spikes is fed in along the upper surface of the table, and is cut off in 

 strips, of suitable size, across the edge of an opening in the top of the 

 table, by a vibrating shear-arm working above, and these are pointed 

 afterwards between the said shear-arm and the table. The cam spoken 

 of has an intermittent motion, and is made to carry the spike Avithin 

 the hollow space of the table, and allow it to stop under a holding die 

 which receives it, when a heading tool conies down and completes the 

 operation. 



MACHINERY FOR COOPERAGE. 



THE London Times furnishes the following description of a new method 

 of constructing casks and barrels, recently put in operation in that city. 

 The staves of the cask are first cut with straight sides, the circular saw 

 being placed at a right angle with the oak plank. The stave is then 

 placed horizontally and bent into a curve by a powerful machine, and 

 brought into contact with a circular saw on each side of it, placed at an 

 angle. This process gives the proper shape to the stave, the sides being 

 gradually tapered at the ends, and being made to bulge in the middle. 

 The jointing and backing machine, the new invention, is also used for 

 this purpose, and is more rapid in its execution than the angular saws ; 

 it in fact works with the most marvellous rapidity and precision. The 

 staves and one end of the cask are then placed in a machine formed 

 of iron rods, called a trussing machine ; each rod acts upon a separate 

 stave, and the whole of the staves being equally compressed into a cir- 

 cle, the hoops are placed around them and the cask is complete. The 

 neatness and finish of the work is equal to what a good cabinet-maker 

 can produce, every part being true and accurate. The calculation is 



