MECHANICS AND USEFUL AETS. 125 



been done in 33 days, that in "Warwick in 20 days, and that at Saltaire, to 

 supply the work-people with drinking-water, in 29 days. 



IMPEOYEifEXTS IX WEEXCHES, VICES, ETC. 



Self- Adjusting Screw- Wrench. The distinctive feature of an improved 

 screw-wrench recently patented by Mr. A. Hotchkiss of Sharon Valley, Conn., 

 consists in the extreme facility with which it is adapted to different sized 

 bolts and nuts ; the movement being accomplished with ease by pressing with 

 the thumb upon a projection on the movable portion of the wrench. The bar 

 is hollowed on the front side, and armed with cross grooves which transform 

 it in fact into a portion of a nut. A loose hollow screw, or rather a threaded 

 thimble, is attached to the movable jaw and fits accurately into the grooves 

 described, being pressed into contact by a concealed spring. The strain on 

 the wrench when applied to use tends to force the screw into still closer con- 

 tact with the grooves, so that all possibility of slipping is avoided, while at 

 any moment a gentle pressure on the projection raises the screw out of con- 

 tact and allows of its being shifted. If greater accuracy of adjustment should 

 be required, it is obtained by revolving the screw or threaded thimble. The 

 movable jaw is of malleable iron. The hollow screw is fitted on a nicely- 

 turned projection on the jaw. The bar is of wrought-iron, forged hi one piece 

 and case-hardened ; the whole constituting one of the strongest as well as 

 most convenient screw-wrenches in existence. 



Improved Wrench. A novel device for a wrench has been patented by 

 Alden Graham of Roxbury, Mass. Two nearly straight pieces of steel are 

 attached, by pivots through then: centers, to the end of a suitable handle, and 

 form the jaws by which the nut to be turned is seized. The jaws are placed 

 at right angles to the handle, and are hung in a slot in the latter. The backs 

 of the jaws are furnished with screw threads, and are encircled by a corre- 

 sponding screw ring, by turning which the ends of the jaws may be opened or 

 closed at pleasure, and thus adjusted to suit any size of nut. There is a 

 ratchet arrangement which permits the turning of the nut without removal of 

 the wrench after the jaws have been adjusted. 



Improved Machine Punch. An improved attachment for a machine punch 

 was exhibited at the Fair of the American Institute. It consists hi a slight 

 handle for stopping, or rather for starting the motion. The toggle-levers 

 which work the punch are of such length that a wedge-like piece is required 

 to interpose between them and the head of the punch, in order to render the 

 movement effective. A small hand-lever controls this wedge, keeping it con- 

 stantly withdrawn except when touched by the operator. The result is that 

 the workman takes as much tune as he pleases hi adjusting the metal to "be 

 punched, instead of placing it hurriedly and often imperfectly, as in the old 

 plan. 



Improved, Vice. A patent for an unproved vice has recently been issued to 

 R. W. Davis of Yellow Springs, Ohio, in the construction of which the mov- 

 able jaw is furnished, near its base, with a guide-piece, which passes through a 

 slot in the fixed jaw : the latter acts also as a guide, which passes through the 



