CLAY WORKING INDUSTRIES. 159 



and only made workable by the aid of efficient machinery, and the dies 

 are well arranged to promote an easj' flow with as little friction or holding 

 back of the surface as is possible, then the defects can be almost obviated. 

 Instances are not uncommon of where the very best structure has been 

 attained in this way, but it could not be maintained continuously. 

 Sometimes it is attained by sacrificing the outside appearance of the bar 

 by using clay which is too short and tender and devoid of enough plas- 

 ticity to make it hold together well. 



The adaptation of auger machinery to paving material has been very 

 greatly assisted by the use of the shale deposits of the state. These shale 

 clays are really the only class of clays which will give wide success to the 

 auger machine for this purpose. As a maker of building brick the auger 

 machine is without an equal, for the structure of the bar has but very 

 little to do with the value of the product. But with the paving brick 

 the structure is all important. 



The method of handling the bar when made, is a subject scarcely 

 less important to the brick maker than the structure is to those who 

 use the brick, as the cost of the product and its surface finish are largely 

 influenced by this part of the work. 



The usual method of handling the output of the side cut machine 

 is by an ingenious mechanism known as the side cutting table. 



The bar of clay is received on a smooth plate which is kept well 

 greased to assist the clay in slipping over, it freely. When the bar has 

 advanced along the plate to a sufficient length, the operator by use of a 

 powerful lever draws a set of parallel wires, strung on a metal frame, 

 through the clay, cutting it into parallel sections of equal length: These 

 are side cut brick. At the conclusion of the cut, the brick are lying close 

 to each other, merely separated by the thickness of the cut which the 

 wires have made. On the return motion of the lever the cut of brick, 

 usually ten or twelve in number, are slipped adroitly to one side on a 

 wooden pallet, to make room for the continuously advancing bar of clay. 

 When thus removed, the bricks are taken to the dryers or to the repress- 

 ing machinery. 



This process of cutting brick by hand and removing them on a 

 pallet, limits the production which can be attained on a side cut machine 

 very greatly. The amount of clay which a good side cut machine is 

 capable of putting out into a well formed bar is enormous, but the amount 

 of this bar which can be cut on any common side cut table is limited to 

 about 30,000 bricks in ten hours. By working the hands by relays, and 

 driving everything to the utmost, more can be managed, but 30,000 con- 

 stitutes the economical limit of the table. 



One great impediment to the speed of the operation of cutting brick 

 by the common side cut table, is the constant use of dexteruy and strength 

 which is called for in disengaging the block of freshly cut bricks, and 

 moving them out from in front of the constantly approaching bar. 



