£ i8 9 ] 



XIV. Defcription of a Machine for drawing Bolts hi and 

 out of Ships. Invented by Capt. William Boltom 

 of the Navy. From Tranfa£tions of the Society for the 

 Encouragement of Arts, &c. Vol. XVI. 



JL HE gold medal was voted to Captain Bolton for this 

 contrivance, a model of which is preferved for the ufe of the 

 Public in the Society's rcpofitory. 



AAAAAA (Plate IV.) is the frame of the machine. 



B, a cylindrical tube, having a female fcrew in the infide. 



C, a wheel with teeth attached to the cylinder B. D, an 

 endlefs fcrew adapted to the wheel C. E, handle of the 

 winch. F, the bolt drawing out. GG, blocks to fupport 

 the frame. H, a hollow piece of fteel, having on its out- 

 fide a male fcrew, whofe threads work within the female 

 fcrew in the cylinder B. To this piece of fteel the bolt is 

 to be riveted. I, a femicircular piece of fteel, which is to 

 be introduced into the notches on H, when a fimilar notch 

 lias been cut in the head of the copper bolt, which by this 

 means is prevented from turning in H, while drawino-. K, 

 the bolt, as prepared to receive the machine. L, a fteel bar, 

 fomewhat (mailer than the bolt to be drawn, having at one 

 end a male fcrew, A, and at the other end another male 

 fcrew that fits into the female fcraw in B. M, a fection of 

 a male (crew, having a fquare hole larger than the bolt. 

 N, a bolt with a male fcrew at one end ready to be 

 drawn in. 



The machine, of which a plate is annexed, confifts of .a 

 frame fupporling a cylindrical female fcrew tube. On this 

 tube is mounted a wheel with teeth adapted to an endlefs 

 fcrew fitted to the frame, and worked by a handle. 



To draw the Holt out. 

 '[ he head of the bolt muft be cut off, and a hole made in 

 the timber big enough to receive the male fcrew H, which 



is 



