Machinery and Methods of Cutting Specimens. 123 



gives rod B B also a rotary motion, by which means the specimen, after 

 being clamped in the jaws D D, may be set at any required angle for 

 cutting. 



¥ F. Long screw resting on shoulder at upper cut of A A, by the 

 use of which the long arm B B may be adjusted in any position upon 

 the rod A A. 



D D. Vise jaws sliding upon arm B B, and holding specimen to be 

 cut. 



C 0. Rod passing through jaws D D. Thread and nut for fine 

 adjustment; rachet and catch at the long end c c for quicker man- 

 ipulation or coarse adjustment. 



E P. Rachet and pinion attachable to jaw at Q and arm at R, by 

 which specimens too large to be cut by one sweep against cutting 

 wheel may be passed horizontally along the square arm B B, and so 

 produce a continuous cut upon one plane to any required length. 



0. Iron frame holding the apparatus. 



GL Cutting disc of iron, steel, tin or copper, of any desirable 

 thickness ; the diameter I generally use is from six to twelve inches. 



H. Mandril supporting cutting disc, about twelve inches above the 

 table, resting in bearing run by a cone pulley, corresponding to one 

 upon main shaft, by which the rapidity of the revolutions of the cut- 

 ting wheel may be raised as required. 



A specimen from which sections have been taken, showing the 

 saw-marks upon its surface, is represented between jaws D D. 



Plate l f fig. 1. — Holder with ball and socket joint, so arranged as to 

 fit into the jaws on the horizontal arm of the crane, plate 2, and by 

 means of which small specimens cemented upon [face-plate C may be 

 adjusted to any required angle for cutting. 



A A. Jaws with concave surfaces, in which the spherical end of 

 holder B fits accurately. 



B. Holder upon which a circular face-plate C may be attached at 

 screw D. 



C C C. Circular plates upon the faces of which small specimens of 

 rocks or fossils may be cemented, and afterward adjusted to any required 

 angle for cutting. 



S. A specimen cemented upon face-plate C ready to be placed upon 

 holder B for cutting. 



Plate l,fig. 2. — Horizontal turn-table upon which a specimen to be 

 cut is clamped. 



A. Square cast-iron base or socket, which is held in iaws of hori- 

 zontal arm B B, plate 2. 



B. Circular table revolving horizontally upon base A, and manipu- 

 lated by gearing at C. ' 



