NOTICE OF THE MACHINERY AND METHODS OP 



CUTTING SPECIMENS OF ROCKS AND FOSSILS 



AT THE 



NEW YORK STATE MUSEUM OF NATURAL HISTORY. 



By James W. Hall. 



The cutting of sections of rock and fossils has become so important 

 an adjunct to geological study, that any device or invention by which 

 such work is facilitated is worthy of attention. The work of cutting 

 fossils was begun in the New York State Museum with very inadequate 

 means. A foot-lathe, turning a vertical disc of tin, with the speci- 

 men held in one or both hands as the case required, was a step in 

 advance of the first method adopted. But the labor of running a 

 lathe by human power became a serious obstacle when large speci- 

 mens were to be cut, and after some delay an experiment was made 

 with a small steam engine, which was afterward replaced by another 

 one better adapted for the work, and run by the steam from a small 

 upright boiler, which occupies no more space in the room than an 

 ordinary cylinder stove. 



Following this adaptation for working, came the efforts at improve- 

 ment in the method of holding the specimens and presenting them to 

 the cutting disc. After numerous trials and the application of several 

 devices, the experiment resulted in the selection of the apparatus 

 represented on Plate 2. 



This consists of a horizontally revolving tin disc in the centre, and 

 vertical standard at the back of the table, to which is affixed a strong 

 arm or lever. This lever is capable of being revolved by loosening 

 screws at its' connection with the socket which slides on the vertical 

 standard. To this arm or lever are adapted strong vise jaws, which 

 slide backward and forward upon the arm, and are capable of being 

 fixed in any required position by a set-screw. The specimen to be cut 

 is placed between these jaws, the screws firmly tightened, and by a 

 fSen. Doc. No. 38.1 16 



