CHAPTER LIX. 

 SCIENCE AND DOMESTIC ECONOMY. 



ALL branches of applied science are capable of giving us important hints 

 and rendering us great service in all the conditions of our daily life, and as 

 we have at various times throughout this volume mentioned useful domestic 

 inventions applicable for use by means of water, air, etc., we may describe 

 some more particularly relating to the inside of the house, and the science 

 of domestic economy. 



Exterior. 



m 

 Scale de Q-Q$ pour I metre. 



6 OJ o!z W O.t O.i 0.8 o'.T OJ 03 I MitPt 

 Fig. 885. Double window. 



Sometimes during the winter we may feel it very difficult, if not 

 impossible, to keep the room warm. This we can do, however, by means 

 of double windows. 



Why is it that the double window as used in Russia keeps out the 

 cold so well ? Is it because the room is defended against frost by two 

 windows instead of there being only one to resist it ? Not entirely. Such ' 

 an explanation is not sufficient. If one be protected against the exterior 

 cold, it is, thanks to the mass of air which is imprisoned, between the two 

 windows. Extraordinary as it may appear, the air is a very bad conductor 

 of heat, and forms the best insulator that one can find. Thd heat of the 



