124* PLAN OF A MOVEABLE CRANE. 



IX. 



Sedion and Plan of a moveable Crane, capable of heaving four 

 Toils with four Men. Defigned and executed for the Pier at 

 Ramfgate, by Order of the Truftees for the Management of 

 tlie Harbour at that Place. By Mn Peter Keir, of St. 

 Pancras. Communicated by Mr. P. Ke 1 r . 



To Mr. NICHOLSON. 

 SIR, 



Account and de- JL HE crane reprefented in the annexed drawings was con- 



£aL P e!° n0f ^ A ruaed at the rec l uefl of the Ramfgate Harbour Truft. It 

 confifts of a call iron frame, marked A, Plates V. and VI. 

 weight two tons, and 9 feet 7 inches fquare, fupported on four 

 caft iron wheels, two of which traverfe on a centre at B, by 

 the rack work C, to fteer it when moving from place to place. 

 A call: iron upright (baft, D, weight 23cwt. fupported by oak 

 braces ; the weight of the framing and wheel work is fup- 

 ported by a fteeled pivot on the top of the fliaft at F, round 

 which the whole fwings, including the men that work it. 



The drawing is fufficiently plain, to require no farther ex- 

 planation. It has been executed, and may be infpe&ed at any 

 time on Ramfgate Pier. 



I am, SIR, 



Your obedient humble lervant, 

 PETER KEIR. 



Further particu- Upon inquiry, I find that the original inftructions were to 

 !»«• make a crane capable of railing four tons, and that the centre 



piece, or upright fliaft, was at firft made of oak : but that the 

 ftrain for difengaging goods from their ftowage requiring the 

 occafional exertion of a greater power, it was found advife- 

 able to fubltitute the prefent iron piece. The coft of this en- 

 gine was four hundred pounds ; but from the above circum- 

 ftance, and particularly becaufe the expence of patterns, &c. 

 will not again be requifite, I am informed that others might 

 now be made for three hundred pounds each. 



W. N. 



Experiments 



