loo A Machine for drawing Ship Molls. 



is put over the bolt: a flit is then to be made, either by £ 

 fa\v or cold chifTel, in the head of the bolt, to receive the 

 key I, and which correlponds to the flit in H : the bolt 

 head is then to be riveted as firmly as poffible upon H: the 

 cylindrical tube, B, is then to be fcrewed on, turning the 

 whole machine round till it can be done no longer, when 

 the endlefs fcrew is to be ufed. If the machine is of a prp- 

 per ftrength, and the riveting well done, the power is fuch 

 as to extract the bolt or break it a but generally it will be 

 drawn out uninjured. 



To draw Bolts into Ships. 



It will be necefTary to have a bar, L, which I recommend 

 to be made of fteel, long enough to pafs from the infide to 

 the outfide of the fliip, and fomewhat fmaller than the cop- 

 per bolt intended to be drawn in. This may be called a 

 conductor. On one end fliould be a male fcrew, a ; the 

 bolt to be drawn in thoukl be tapped at one end to receive 

 the male fcrew, a, on the conductor, and at the other end 

 fliould he another male fcrew that fits into the female fcrew 

 in B ; after which the operation is the fame as drawing a 

 bolt out, and the machine fliould be applied accordingly. 

 When the bolt arrives at its deftined place, it may be fecurcd 

 on the infide by a nut, which is as good a way of faftcning 

 as clinching, and much more expeditious. 



This machine, though onlv of the height of eighteen 

 inches, will draw bolts in or out of any length; for, after 

 the bolt has rifen to the top of the tube, it will only be ne- 

 cefTary to fcrew the machine back, and follow up the work 

 with blocks of timber, as represented in the drawing. 



Note. If the upper part of the hole in H he made fquare, 

 larger than the round hole as fhewn at M, and the head of 

 the bolt riveted into it, it will do away the neceffity of the 

 key, I, render the machine lefs complicated, and fave much 

 time and trouble. 



6 XV. Ds~ 



