20 BULLETIN" 102, UNITED STATES NATIONAL MUSEUM. 
of manuf actured-gas development must stand or fall. This measures 
the difference between ultimate success or inevitable failure. 
Merely providing for the three groups of expenditures in the pre- 
ceding section will not yield any profit. Without a fair profit 
there is no incentive for improvement. Without improvement there 
can be no progress or development. Therefore an inducing profit 
is fundamentally necessary to continuously and permanently stimu- 
late development of more efficient utilization methods of our fuel 
resources and extension of public-utility service. 
MISLEADING MANUFACTURED-GAS COST DATA. 
Many published data purporting to show the cost, especially the 
so-called holder cost — that is, the cost of gas delivered into the 
holder — or burner cost — that is, the cost of gas delivered at the 
consumers’ burners — of manufactured gas includes only the element 
{a) of the above analysis. That is, provisions ( b ) and ( c ) were 
omitted with the result that many cost figures given are not correct. 
SIGNIFICANCE OF FIXED CHARGES. 
The rental for the use of the money, provision to ultimately pay 
the money invested, taxes, insurance, replacements, and repairs due 
to age or weather conditions, and some of the executive charges are 
fixed and go on for each of the 8,760 hours of the year and are en- 
tirely independent of the volume of the manufactured-gas enter- 
prise’s business. Of the total money paid by the public more than 
one-half must go to meet this fixed-charge situation. 
Failure to appreciate the significance of this has been responsible 
for many manufactured-gas financial difficulties and inability to 
carry out fuel-conservation measures that were correct from a mere 
technical viewpoint but unsound from the viewpoint of economics. 
The economic and not the engineering features are, for this reason, 
ultimately controlling in all fuel-conservation projects. 
CHARACTERISTICS OF HOUSE HEATING. 
Wide variation in range of seasonal, daily, and hourly fuel needs 
are the dominating features of house heating. Atmospheric temper- 
ature will determine the consumer’s needs and each degree drop in 
temperature will increase the consumer’s demand for heating, as 
shown in Figure 10. 
The consumer will not contract to take a specific amount of gas 
at a definite time but will expect to get all the gas he needs and to 
use it as he needs it. Manufactured-gas service for house heating 
must, therefore, cope with the varying demand, meet the peak-load 
