40 
BULLETIN 102, UNITED STATES NATIONAL MUSEUM. 
USE OF AUXILIARY HEATING APPLIANCES. 
It is desirable, in all cases where possible to have auxiliary heating 
equipment available for supplementing or entirely replacing for a 
short period natural gas for house-heating service, during the peak 
period of the load. Where gas furnaces are used, auxiliary oil 
burners can be installed in such fire pots, or auxiliary coal furnaces 
can be installed alongside the gas furnaces, where the coal furnace 
would discharge its heated air into the gas furnace shell. 
FEW IMPROVEMENTS IN ART OF USING NATURAL GAS. 
On account of the low prices that have prevailed, gas- appliance 
manufacturers have not been stimulated to the development of effi- 
cient gas-using equipment. There have been few improvements re- 
sulting in increased efficiency in the last 15 years. In testing house- 
heating furnaces it has been found that : • 
1. The use of natural gas in the fire pot of a coal furnace gives an 
efficiency of about 25 per cent. 
2. The use of natural gas in the ordinary gas furnace gives an 
efficiency of about 35 per cent. 
3. The use of natural gas in a correctly designed and built gas 
furnace, where the construction conditions permit the fullest utiliza- 
tion of the heat in the gas, gives an efficiency of about 75 per cent. 
In tests made by the Bureau of Standards, it was found that the 
ordinary incandescent mantle lamp where used with natural gas 
wasted nearly half of the possible heat that could be used if such 
lamps were designed for as efficient operation on the high heating 
value natural gas as they give on the low heating value manufac- 
tured gas. 
In tests made by the department of home economics, Ohio State 
University, the efficiencies of a natural gas range varied from 37 per 
cent with 0.2 of an ounce pressure down to 13 per cent at 4-ounce 
pressure, 1 while with a manufactured gas range, using natural gas, 
the efficiencies varied from 43 per cent at 0.2 ounce pressure to 23 
per cent at one-ounce pressure. 
COOKING AND HEATING DISTINGUISHED. 
In a heating operation it is merely necessary to secure perfect com- 
bustion in the heating device, because in so doing all of the available 
heat in the gas can be utilized. In cooking it is not only desirable 
to secure a perfect combustion, but absolutely necessary to direct the 
heat to a particular place, in a particular manner, and sometimes at a 
particular time. It is for this reason that gas-cooking operations are 
1 Ohio State University Bulletin, vol. 22, No. 28, May, 1918 : Effect of Gas Pressure on 
Natural Gas Cooking Operations in the Home. 
