392 On the Construction of Kitchen 



commend them as I recommend things which I know 

 from experience to be useful. 



I shall now proceed to give an account of several 

 precautions in the construction and use of these reg- 

 ister-stoves for boilers, which have been found to be 

 necessary and useful. 



The circular registers are so constructed that, by 

 turning them round, they may be so placed as either 

 to close entirely the holes in the flat plate on which 

 they lie, or to leave them open more or less. Now, 

 as there is no passage by which the smoke can go 

 off from the fire-place into the chimney but through 

 these holes, care must be taken never to attempt to 

 kindle the fire when both these registers are closed, 

 and never to open one of them without having first 

 placed a hollow cylinder on it and a fit saucepan or 

 boiler in the cylinder, to close it above. It can hardly 

 be necessary that I should add that care must always be 

 taken to put water or some other liquid into the boiler 

 to prevent its being burned and spoiled by the heat. 



The state of the register, in regard to its being more 

 or less open, cannot be seen when the boiler is in its 

 place, as the openings of the register are concealed by 

 it and by the cylinder in which it is suspended. But, 

 although the state of the register under these circum- 

 stances is not seen, it is nevertheless known ; and the 

 heat which depends on the dimensions of the opening 

 left for the passage of the flame may at any time be 

 regulated with the utmost certainty. By means of a 

 projecting pin or short stub, represented in the Fig. 49, 

 belonging to the lower (fixed) plate, and which is 

 cast with it, the movable circular register is stopped 

 in two different positions, in one of which the open- 



