Miscellanies. 



183 



not therefore go into details except to describe the cementing fur- 

 nace, the exact dimensions of which we have been able to procure. 

 Figs. 1, 2, and 3, show the arrangement of the furnace. It is 

 rectangular and covered by an arched vault ; it contains two cement- 



ing troughs C, constructed of brick.* These troughs are two and 

 a half feet wide, three feet deep, and twelve feet long; they are 

 placed on each side of the grate, A, B, fig. 2 ; the latter extends 



* These troughs are soraelimes made of refractory stone. 



