368 On the Construction of Kitchen 



of a boiler with a steam-rim, covered with a conical 

 double cover made of tin : 



Fig. 41. 



In this and the following figures, A, B, represents a 

 section of part of one side of the (double) cover of the 

 boiler; C, D, the steam-rim and part of one side of 

 the boiler; E, the descending rim of the cover; and 

 F, G, the level of the water in the steam-rim, all of 

 one half size. 



This construction was found to be attended with an 

 inconvenience, which, indeed, might easily have been 

 foreseen. When the steam, on being confined, became 

 strong enough to force its way under the descending 

 rim, E, of the cover of the boiler, the water in the steam- 

 rim was frequently blown out of it with considerable 

 violence and dispersed about the room. To prevent 

 these disagreeable accidents, the form of the upper part 

 of the steam-rim was altered. To make a proper finish 

 to the boiler, the edge of its brim (which forms the top 

 of its steam-rim) had been turned outwards over a 

 strong wire. It was now turned inwards over the wire ; 

 and the outside or rising part of the steam-rim, instead 

 of being made sloping outwards, was now made vertical. 



A complete idea of these different alterations, and of 



