Fire-places and Kitchen Utensils. 315 



had occasion to know since that several persons have 

 adopted them. I have likewise been made acquainted 

 with the results of many of the trials that have been 

 made of them, and with the complaints that have 

 been brought against them. As I am more than ever 

 of opinion that iron ovens will always be found useful 

 when they are properly constructed and properly man- 

 aged, I shall in this place add a few observations to 

 what I have already published concerning them. 



And, in the first place, I must observe that a small 

 iron oven stands in need of a good door; that is to say, 

 of a door well contrived for confining heat ; and the 

 smaller the oven is, so much the more necessary is it 

 that the door should be good. 



The door must not only fit against the mouth of the 

 oven with accuracy, but it must be composed of mate- 

 rials through which heat does not easily make its way. 



An oven door constructed of a single sheet of plate 

 iron will not answer, however accurately it may be made 

 to fit the oven ; for the heat will find its way through it, 

 and it will be carried off by the cold air of the atmosphere 

 which comes into contact with the outside of it. The 

 bottom of the oven may be made hot by the fire under 

 it ; but the top and sides of it cannot be properly heated 

 while there is a continual and great loss of heat through 

 its door. But an oven, to perform well, must be very 

 equally heated in every part of it. 



If the flame and smoke of the fire be made to sur- 

 round an oven on every side, and if the fire be properly 

 managed, there can be no difficulty in heating an iron 

 oven equally, and of keeping it at an equal temperature, 

 provided the loss of heat by and through the door be 

 prevented. 



