424 Of Food. 



In this manner double bottoms may be made to 

 saucepans and kettles of all kinds used in cooking ; 

 and this contrivance will, in all cases, most effectually 

 prevent what is called by the cooks burning to* 



The heat is so much obstructed in its passage 

 through the thin sheet of air, which, notwithstanding 

 all the care that is taken to bring the two bottoms 

 into actual contact, will still remain between them, the 

 second has time to give its heat as fast as it receives 

 it to the fluid in the boiler, and consequently never 

 acquires a degree of heat sufficient for burning any 

 thing that may be upon it. 



Perhaps it would be best to double copper sauce- 

 pans and small kettles throughout ; and, as this may 

 and ought to be done with a very thin sheet of metal, 

 it could not cost much, even if this lining were to be 

 made of silver. 



But I must not enlarge here upon a subject I shall 



* This invention of double bottoms might be used with great success by dis- 

 tillers, to prevent their liquor, when it is thick, from burning to the bottoms of 

 their stills. But there is another hint which I have long wished to give distil- 

 lers, from which I am persuaded they might derive very essential advantages. 

 It is to recommend to them to make up warm clothing of thick blanketing for 

 covering up their still-heads and defending them from the cold air of the atmos- 

 phere, and for covering in the same manner all that part of the copper or 

 boiler which rises above the brick-work in which it is fixed. The great quantity 

 of heat which is constantly given off to the cold air of the atmosphere in contact 

 with it by this naked copper not only occasions a very great loss of heat and of 

 fuel, but tends likewise very much to embarrass and to prolong the process of 

 distillation ; for all the heat communicated by the naked still-head to the 

 atmosphere is taken from the spirituous vapour which rises from the liquor in 

 the still ; and, as this vapour cannot fail to be condensed into spirits whenever 

 and wherever it loses any part of its heat, as the spirits generated in the still- 

 head in consequence of this communication of heat to the atmosphere do not 

 find their way into the worm, but trickle down and mix again with the liquor in the 

 still, the bad effects of leaving the still-head exposed naked to the cold air 

 is quite evident. The remedy for this evil is as cheap and as effectual as it is 

 simple and obvious. 



