45 S Improved Crane and Flexible Chains. 



AB, the perpendicular, formed of two oaken planks, each 

 eighteen inches wide, four thick, and sixteen feet long, let 

 into cast-iron mortise-pieces CD. 



EE, the barrel for the chain which works between the 

 two planks of the perpendicular. 



F, the top piece, containing in the middle a dove-tailed 

 mortise, into which H, a stock for the gib, is fixed ; an iron 

 bolt goes through the whole, for greater security. The 

 stock projects two feet from the mortise, and two planks 

 I, K, eighteen inches deep, and four thick, are bolted one on 

 each side of it, to form the gib, the interstices between these 

 planks forming a birth or space for the top block L to slide 

 in. This block is made of cast-iron, and has a groove three 

 inches deep on each side. 



M, the diagonal stay, is of the same dimensions as the gib, 

 formed in a similar manner, and connected to the perpen- 

 dicular by being let into the lower mortise-piece D. 



N, the handle or winch which turns a small pinion O, fixed 

 on the same axis; this pinion works in the teeth of the 

 wheel P, moving on the same axle as the barrel E, on which 

 the chain R lies in spiral grooves. 



S, the block and hook by which the goods are raised. 

 Fig. 2. is a side view of the handle N, the pinion O the 

 toothed wheel, and the barrel E placed betwixt the two up- 

 rights AB. 



Fig. 3. shows upon an enlarged scale part of the barrel E, 

 and some of the chain lying in its proper position in one of 

 the spiral grooves, or channels : it is to be noted that the 

 lower edge of one link lies in the groove, and the next link 

 upon the surface of the barrel, and that by this means the 

 chain is prevented from twisting in winding upon the barrel. 

 Fig. 4. shows a section of part of the barrel E, in order 

 to point out clearly the manner in which oneJink lies with- 

 in it, the other link on its outside; it is contrasted by Fig. 7* 

 the old method of working chains. 



Certificates, dated November 22d, 1S04, from Thomas 

 Blackmore, John Swift, John Ball, Joseph Felton, Benjamin 

 Heylehurst, Benjamin Hunt, and Thomas Hatchhess ; who 

 declare that they were present at the trial of the experiments 



above 



