<2Q6 DESCRIPTION 01^*Atf IMPROVED MlHi 



XIII. 



description of an improved Mill for grinding hard Suhfiances. 

 By Mr. Garnett Terry, from the Tranfaciions of the 

 Society of Arts, who adjudged the Silver Medal to the Inventor. 



Fn S P roved° f ^ R * Teri > wh ° fe refidence is No - 20 * Cit y Road > Finf- 

 mill. ^ ur y Square, has conftructed this mill on a large fcale, and 



there is alfo a model deposited in the Society's collection. 



Plate X. Fig. 1. A. The hopper, or receptacle of the 

 articles which are intended to be ground. 



B* A fpirai wire, in the form of a reverfed cone, to regu- 

 late the delivery of them. 



C. An inclined iron plate, hung upon a pin on its higher 

 end : the lower end refts on the grooved axis D, and agitates 

 the wire B. 



D. The grooved axis, or grinding cylinder, which acts 

 againft the channelled iron plate E. 



F. A fcrew on the fide of the mill, by means of which the 

 iron plate E is brought nearer to or removed further from the 

 axis D, according as the article is wanted finer or coarfer. 



G. The handle, by which motion is given to the axis. 



H. The tube from whence the articles, when ground, are 

 received. 



%* The front of the mill is taken off, in order to fliow its 

 interior conftruction. 



XIV. 



Remarks on. Dr. Thomfon's Theory of Combajlion. By C. i?. 

 (Received June 15, 1802.> 



General remarks JL HE fcientific world are fo highly indebted to Dr. Thom- 

 fon's Vheorv" 1 " ^ on ^ or manv original communications, and for the very per- 

 and the diftinc- fpicuous manner in which he has explained many of the phe- 



ti on between no mena of chemiirry, that every thing that is prefented to the 



combufhon and . J _. . * . . . , , 



•xigenation. world under the ianction of his name, is intitled to much con- 



fideration : if in ibme inftances we are induced to hefitate in 

 the yielding of our aflent, we cannot but do juftice to the in- 

 genuity of his reafonings, and at the fame time acknowledge 



the 



