298 



Hogg's Patent conical Boiler, 



cast in one piece, to which the outside boiler, made of wooden 

 staves, is fitted, and well bound with iron hoops. The whole stands 

 on a square iron plate {e e), supported by the brickwork of the 

 ashpit (y); and, from the top of this plate, the ring gg rises and 

 fits into a bead on the bottom of the furnace. In this ring there 

 are two pins; the one is shown at h on which the grate turns, 

 and at J there is a hole through which the other pin (k) passes, 

 and supports the grate. 



The fuel is put in at the top of the pipe c, and receives air 

 from the front of the ashpit, which has a register door, as shown 

 by the elevation {Jig. 105.) ; the draught passing up the pipe b 

 {Jig. 104.), in which there is a damper {I). The two water-pipes 

 {m m) are fastened on either by bolts or screws, and they can be 

 made to lead from the boiler either horizontally, or perpendicu- 

 larly ; as shown by the elevation y^. 105. n is an expansion 



