114 



Our Surroundings 



end of the box, and test the currents of air by placing smoking 

 joss sticks at the openings; (b) open all the holes on one end, 

 leaving those on the other end closed, and test in the same 

 manner; (c) open all the holes in the lower part, leaving the 

 upper holes closed, and test as before; (d) open all the holes in 

 the upper part, leaving the lower holes closed, and test. Which 

 method gives the best ventilation? 



The Fireless Cooker. A fireless cooker is a box into which 

 hot food is placed to cook without the further use of fire. It is 

 made of materials which do not readily conduct heat. It consists 



of an ordinary box within a 



/Lid 

 -Automatic Steam Vent 



.Pure Aluminum Lining 

 /Air Space 



NMineralWool Insulation 

 joking Can 



till! 1 1 IIIIH H^nHnf Pads 

 THE FIRELESS COOKER 



It cooks hot foods by their own heat. 



larger box whose bottom and 

 sides and top are from four 

 to six inches thick and made 

 of, or packed with, paper or 

 with some other non-heat- 

 conducting material. After 

 the food to be cooked is 

 brought to the desired tem- 

 perature by heating, it is 

 placed in the box and tightly 

 covered. Since the heat es- 

 capes very slowly, the food is 

 kept at about the same tem- 

 perature it was when put in 

 A piece of soapstone may also 



the box and continues to cook. 



be heated and placed in the box below the food to give added heat. 



The main objects in using a fireless cooker are to save fuel 

 and to lighten the burdens of the housekeeper. A fireless cooker 

 is not an expensive article. Any family wishing to use one can 

 make it by securing two boxes of proper size and the necessary 

 packing material. 



The Vacuum Bottle. The vacuum bottle works on some- 

 what the same principle as the fireless cooker. It consists of a 

 glass bottle inside of a larger bottle and sealed to it at the 

 neck. By creating a vacuum in the space between the two 

 bottles, that is, by removing the air, it becomes impossible for 



