UORIVG MACIIIxSE. §3 



Boring Machine, 



I take this opportunity of mentioning a trial that I Boring ma- 

 lately made of Mr. Ryan's patent Boring Machine, for Rygn. it cuts 

 exploring the strata of mineral countries. This machine out a circular 

 acts like the surgical trepan^ and cuts a circular hole, {iJl^t^ ^j^ *"? 

 leaving a core in the middle which is drawn up from time 

 to time by a pair of self-closing tongs. ^ 



I found that this gentleman's machine, from his want 

 of knowledge how to push his own invention, had not 

 obtained due credit; I therefore invited him to try his 

 machine at my hoaSe, that I might witness the result of 

 t4ie experiment. 



Two men, relieved from time to time, cut a truly cir- Five inch hole 

 eular hole, five inches and a quarter in diameter, through Jj^eltone^^ 

 a block of hard limestone, leaving a core a little taper of 

 four inches and a half diameter and six and three quarters 

 in length, which core is now in my possession. It is as 

 true and as smooth as if turned and polished in a lathe, 

 and the under surface shews exactly the fracture by 

 which it was detached from the block at bottom. 



By this contrivance mines may be ventilated at small The pieces be- 

 expense, the specimens of strata that are bored through en^tre^"|^ord^ 

 may be brought up whole and unmixed, no deceptioi) very accurate 

 can take place ; and not only the dip, but the fracture, knowledge of 

 lap, and accidents to which each stratum is liable, may ' 



be determined at any depth. True vertical and horizon- 

 tal sections may be previousjy obtained of any spot where 

 it is propoT5ed to sink shafts ; and the subterraneous to- 

 pography of a whole district may be laidWown upon a 

 map with confidence before any groat expense is hazarded 

 pn mere speculation. 



I am, Sir, 

 With regard and esteem, ^ 



Your faithful humble servant, 



RICH. LOWELL EDGEWORTH, 



M^ 



