MANUFACTURED GAS IN THE HOME. 
15 
This burner never has a mixer for premixing part of the air as is 
required in the Bunsen blue-flame burner described in the preceding 
section. It can be used only for room-heating purposes and then only 
in positions where the flames do not impinge on each other or on any 
surface. 
COOKING REQUIRES LITTLE HEAT. 
That cooking operations require relatively low temperatures is not 
generally appreciated ; that is, in all boiling operations the tempera- 
ture is never above 212° F. and in all baking, roasting, and broiling 
operations it is always below 500° F. 
The total amount of heat required to cook the food is very small 
and the heat that does useful work must not be merely delivered 
into the cooking vessel but must actually penetrate and get into the 
food. The big problem is, therefore, in directness and efficiency 
in getting the heat into the food and efficacy in insulation or holding 
it in. 
STEPS NECESSARY FOR CORRECT COOKING. 
a. The gas must be properly burned; that is, it must be properly 
mixed with air so as to burn with a pale blue nonluminous flame. A 
luminous flame will be wasteful and will deposit soot on the cooking 
vessel. 
b. The flame must be properly directed; that is, the tip of the 
flame must come close to the cooking vessel. If the flame is too short 
to reach the cooking vessel, or is blown to one side by a strong draft 
of air, gas will be wasted, a longer time will be required, and if the 
flame tip is too far away it may be impossible to cook, although the 
short, improperly directed flames may be kept burning a long time. 
c. In top-burner operations the heat generated by the burning 
gas must be delivered through the cooking-vessel walls and through 
the food. Grid or open-top stoves are desirable for good service so 
as to get the most direct path for the heat from the flame into the 
food. The heating of a baker is merely heating the inside of a small 
room and it should be fitted with a flue connection. 
d. The use of insulated ovens so as to cut down the radiation 
losses will usually halve the gas consumption for a given gas opera- 
tion as compared with the uninsulated oven. Thermostat control 
for gas consumption will result in better oven service, less gas con- 
sumption, and a saving in burned food ; that is, it takes the “ guess ” 
out of cooking and insures duplication of results. 
