Fire-places and Kitchen Utensils. 393 



ings for the flame are as wide as possible, and in the 

 other they are quite closed. When the handle by 

 which the circular plate is turned round is pulled as 

 far forward as possible towards the front of the brick- 

 work, the register is wide open. In this situation it 

 is represented in the Fig. 49. When it is pushed as 

 far backwards as possible, the register is closed ; and 

 its situation at any intermediate station of the handle 

 between these two limits of its motion will at any time 

 show the exact state of the register. 



That the handles of the register plates may not in- 

 terfere with each other,, they are placed on the sides 

 of their plates which are farthest from the fire ; con- 

 sequently they are as far from each other as possible. 

 The form of these handles is such that they never be- 

 come very hot, although they are of iron and of a piece 

 with their plates, being cast together. The cold air 

 of the atmosphere passing freely upward through a 

 conical hole (left in casting) in the centre of the knob 

 of the handle, the heat is carried off by this current 

 of air almost as fast as it arrives from the circular plate. 



There is a circumstance to which it is absolutely 

 necessary to pay attention in setting the large flat iron 

 plate in the brick-work, otherwise the machinery will 

 be liable to be soon deranged by the effects of the ex- 

 pansion of the metal by heat. The bottom or under 

 side of this plate must be everywhere completely cov- 

 ered and defended from the action of the flame by 

 bricks or tiles. This is very easy to be done ; but at 

 the same time, as it requires some care and attention, 

 it is what workmen are very apt to neglect if they are 

 not well looked after. As this plate is very large, if 

 great care be not taken to prevent its being exposed 



