Veicnplicn of a Screw Press. 24^ 



and if the invention meets with the approbation of tlie so- 

 ciety, 1 hope to be rewardttl according to its uient. 

 I remain, with respect, sir. 



Your nicst obedient servant, 



Tf /-/ J T 1 William Bullock. 



Mr. Charles layLor. 



JJescr'iption of Mr. JViUiam Bullock' i improved Drawback 

 Lock. (Plate F. Fig. 1.) 



A, Is the new iron latch here affixed to an old common 

 drawback house lock. 



B, an iron pin at one end of the latch, on which pin It is 

 moveable. 



C, a projecting part of the latch, which, when the 

 conniion spring bolt D of the lock is drawn back, in the 

 usual manner, is forced into the nick on lis higher part at 

 JE, by the spring F, underneath the latch. 



The bolt D tlien remains within the lock, until, on closing 

 the door, the reliever G gently presses on the lock box, 

 fixed in the common way on the door cheek ; which pressure 

 draws the projecting part C out of the nick E, and permits 

 the end of the bolt D, by the force of the spring G, to slide 

 jnto the lock box, and fasten ihe door. 



XLV. Descripthm of a Screw Prc<>s with an expanding 

 Poiver. By Mr, William Bowlek, of Finsbury- 

 Sireet *. 



sin, 



JL HE screw- and spring-press which I have the honour to 

 present to the inspecticjn and for the approbation of the 

 ^jociely for the Encouragement of Arts, &e. will, I trust, 

 be found in a superior degree adapted to the purpose of 

 pressing bodies in general, but more particularly cheeses, 

 apples, linen, &c. because such things require a firm anq, 

 an unrelaxing pressure : — and this is a peculiar advantage 

 incident to this machine; for after It is set, or the spring 

 screwed well up, it will be found, that as the uriicLe. 

 pressed shrinks trom It, so the spring, owing to its peculiar 

 expanding power, gradually follows the object of its pres- 

 sure, and hence continues to maintain an uniform and 



• From Tiomartiotts of tbt So ieiy of Am, &c. vol. xxi. — A bounty 

 |if iin guineas was voted to the author by tlie tocicty. 



equal 



