2 
BULLETIN 102, UNITED STATES NATIONAL MUSEUM. 
natural gas are so crude and grossly inefficient that they can not be 
used at all with manufactured gas and this will make a marked de- 
mand for better manufactured-gas appliances. 
FIO. 1. — GROWTH OF MANUFACTURED-GAS SALESI FOR PUBLIC-UTILITY SERVICE IN THE 
UNITED STATES. 
ANNUAL SALES /N B/LLION CU3/C FEET 
