114 



CHEMICAL MANURES. 



The superphosphate " den " a has interior lateral sides b arranged 

 in grades, reversed above, in such a way as to give to the final block 

 a form approaching that of a cylinder. The floor of the " den " 

 is pierced in its centre by a longitudinal opening c covered by a 

 vv^ooden trap d, one of the ends of which is fitted with a ring handle 



Pig. 27. — Benker and Hartmann's Mechanical Remover of Superphosphate from 



" Den" (plan). 



e. The " den " has in its face a circular opening/ shut by a door g in 

 two parts. This " den " is traversed through its whole length by a 

 shaft h, supported on two suitable bearings so as to dovetail into 

 and continue a screw shaft i mounted in a fixed screw j. A cog- 

 wheel k, geared to the outside screw part of the shaft i, has a claw 



* l^'NT^V^Z/^^Ay^^VVV^, 



Fig. 28.— Benker and Hartmann's Mechanical Remover of Superphosphate 



from " Den " (detail). 



m, which penetrates into a longitudinal gutter ?i of that shaft, so as 

 to' connect the shaft i with the wheel k in the direction of rotation, 

 but letting it glide freely. On the shaft h two arms o and p are 

 fixed diametrically opposite one another, one of which o forms a 

 sort of compound knife, fitted with teeth q projecting from the 



