114 NATURAL SCIENCE [August 1898 
impurities of any kind. The chief and main object of the develop- 
ment of a Natural Gas field, is to be found in the use of the gas for 
fuel in the generation of motive power for various manufactories. 
In North America there are at least sixteen States using Natural Gas. 
In the State of Indiana, U.S.A., alone there exist about three hun- 
dred Natural Gas companies. The question of the maintenance of 
the supply is an all-important one. In the American States laws 
have been passed with a view to economise the use of the gas, which, 
as now at Heathfield Station, is allowed to rush or burn to waste. 
Experience abroad shows that even the most abundant fields of gas 
are capable of exhaustion. Thus in Indiana in 1889, the average 
initial rock-pressure of the entire field was 325 lbs. to the square 
inch; in 1896 it had fallen to 230 Ibs. to the square inch. On 
the other hand, such gas has been used for ages in China for the 
boiling down of brine for making salt. It seems a pity that the two 
borings at Heathfield should be allowed to seal themselves up with- 
out some effort to test the practical utility of this field of Natural 
Gas. If the tubes were again cleared and relined with perforated 
tubing, and the water in the tube was pumped out, the important 
question of the value of the field, which promises so well, might very 
soon be arrived at without much expense. 
Whatever results may accrue from these lighting and heating 
properties, or whatever the discovery may point to in a commercial 
direction, the fact nevertheless remains that the discovery is a 
subject both interesting and instructive, and, I think, worthy of 
consideration at this conference. 
CHARLES DAWSON. 
UCKFIELD, SUSSEX. 
