On Bonnycastlc's Tiigonomeiry. CI 



the serious attention of the artists and amateurs in general 

 of this country. 



One of its great advantages is, that instead of a copy, as 

 in the case of an engraving or etching, you produce a per- 

 fect fac simile of the original design. And I here take an 

 opportunity of correcting an error, in a short and inaccurate 

 account given by Mr. Nicholson in his Journal, which states 

 that the liquid with wliich the drawing is made required two 

 or three days to drv before it can be printed. The fact is, the 

 impressions may be taken the minute the drawing is made, 

 as the liquid dries almost immediately. Any number of 

 impressions may be taken from the drawing : between 4000 

 and 5000 impressions have already been taken from a draw- 

 ing, without the least alteration. 



This art is also applicable to the printing of the finest 

 wjitino-; and nmsic also has been printed from it with great 

 success. 



Mr. Volwieler, the proprietor of the patent. No. o, Buck- 

 insham-place, Fitzroy-square, is now publishing a work 

 entitled Specimens of Polyautography, consisting of fac-si- 

 mllcs of sketches of the most eminent artists of this coun- 

 try. 



Mr. Volwieler also furnishes stones, &c. for those desirous 

 of multiplying their drawings. H. K. 



X. The Reviewer of Mr. Bonnycastle's Trigovomelry 

 in Reply to the Observations of Mr. Thomas Keith. 



To Mr. Tilloch. 



If Mr. Keith had, in his remarks upon Mr. Bonnycastlc's 

 Trigonometry, confined his animadversions to that work 

 alone, I should have left that gentleman either to notice or 

 to disregard the attack, as he thought proper. But, as Mr. 

 Keith has eonc out of his road to thnjw some imputations 

 upon the judgment of the person who wrote the account of 

 Mr. Bonnycastlc's treatise, I conceive it to be nn act of jus- 

 tice to myself to replv concisclv to Mr. Keith. 



This 



