132 APPLICATION OF CHAINS. 



Lower gudgc- To prevent the inconvenience of the dirt of the floor 

 on* getting into the brass of the lower gudgeon, and thereby 



obstructing the revolution of the crane, those parts are 

 reverse to the common way, the gudgeon being fixed in 

 the floor, and the socket part which embraces it is cast in 

 the bottom of the mortise-piece, as is also a channel to 

 convey oil to the gudgeon. 



Reference to Mr, Gilbert Gilpin'' s Crane, Plate III, 

 Fig,\,%S,4. 



Description of f^v i Represents the crane with all its parts complete^ 

 the crane by ' , - , ^ ^ ' 



references to ^ f ^^7 ^O^' ^^'^^k . 



the plate. A B, The perpendicular, formed of two oaken planks, 



each eighteen inches wide, four thick, and sixteen 

 feet long, let into cast-iron mortise-pieces CD. 

 E E, 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 5 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 perpendicular by being let into the lower mor* 

 tise-pieceD. ■• 

 N5 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 uprights A B. 



Fig, 



