[Proc. Roy. tjoc. Victoria, 23 (N.S.), f'l'. I., 1910.] 



Art. XI II. — Modem Improvement in Rod' Section 

 Cutting ApjHiratus. 



By H. J. GUAYSON, 



Geological Laboratory, University of Melbourne. 



With Plates XIV. -XVII ). 

 [Read 9th June, 1910.] 



1. — Introductory and General. 



The cutting of Rock sections for class use and research work 

 occupied a considerable proportion of the writer's time, and 

 also entailed much labour, until a little over Uvo years ago, 

 when an effort was made to improve upon the apparatus at 

 that time available for rock slicing. To attain this end, it was 

 deemed best to build an entirely new machine, which should 

 be electrically driven and embody all that was best in the 

 earlier forms of lapidary's machine, while introducing such 

 improvements and modifications as a considerable experience of 

 rock slicing had shown would be advantageous. 



At the outset, I may say that where only a feiu sections are 

 likely to be required, a machine of any kind is not an absolute 

 necessity. Given reasonably thin chips or flakes, such as can 

 readily be obtained Avith a hammer, also plenty of time and 

 energy, coupled with a fair amount of skill, and thin sections, 

 in every way comparable with those made with the aid of 

 mechanical devices, can be obtained. Hand work of this 

 character is, however, both slow and laborious, and the pre- 

 paration of any considerable number of sections becomes a 

 serious undertaking. 



In the early days uf rock section making, the professional 

 lapidary was usually resorted to, when a number of sections 

 were required. Naturally, the machine used by him was the 

 one first adopted by the Geologist, who, either from choice or 

 necessity, prepared his own sections. The ordinary lapidary's 



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