554 
stations. The actual weight of fuel used at 
Winnington is one pound per h.-p.-h. This is 
substantially the same as the figure for the 
record-breaking steam-engine inmarine practice 
already referred to; but the latter uses the most 
costly, the gas-engine the least expensive, fuel, 
and this is the vital matter. The gas-engine 
now has attained a mechanical efficiency of 
about 85 per cent. and a thermal efficiency 
exceeding 25 per cent. ; both figures represent- 
ing the practical limit in steam-engine practice 
also, although the former is sometimes ex- 
ceeded. In both engines the efficiency, on the 
basis of the brake horse-power, is about twenty 
per cent., occasionally one or two units higher. 
The Mond gas, with a thermal content of 150 
B.T.U. per cubic foot, sells for twopence per 
thousand ; this can be compared with our own 
illuminating and natural gases, storing 600 and 
1,000 B. T. U. ; of which, respectively, 16 and 
9 cubic feet are used in good gas-engines, per 
horse-power-hour, while of the Mond gas at 
least 75 cubic feet are demanded. 
Summing up the case : It may be said that 
the best work of the large gas-engine gives a 
thermal efficiency substantially the same as 
that of the very best steam-engine while it 
employs a fuel which is considerably cheaper 
than is employed where this comparison is, as 
here, made on the basis of fuel consumed. Its 
‘cost of plant,’*on a large scale, is now quite 
as low. 
The balance sheet of the best single gas- 
engine reported stands thus: 
Heat transformed, B. T. U....... 33.65 
Heat received Heat lost 
from Cylinder-jacket......... 19.28 
. the fuel PiBton\..tdeecescsseoeccees 4.94 
Ja Sth (Of Exhaust valve........... 3.34 
100. Total in cooling water... 27.00 
Heat waste in exhaust, eto. 38.79 
100.00 
This is superior to any steam-engine per- 
formance yet reported. 
During the discussion, Mr. Donkin reported 
in tabular form the best results of tests of gas- 
engines made in the United States with natural 
gas, the richest gas-fuel, either natural or 
artificial, available for large engines. The best 
figures in the table are those obtained in a 
SCIENCE. 
(N.S. Von. XIII. No. 327. 
Sibley College test of a Westinghouse gas- 
engine and reported by Messrs. Millar and 
Gladden in the Sibley Journal of June, 1900. 
The power developed was, net, 606 H. P., the 
mechanical efficiency of the machine 90 per 
cent., the heating value of the gas about 1,000 
B. T. U. per cubic foot, the consumption rang- 
ing from 10 cubic feet per B. H. P. to 8.8 for 
the indicated power. This gives a thermal effi- 
ciency of 25.5 per cent. The same figure is 
obtained, according to Mr. Donkin’s tables, in 
Mr. Humphrey’s test of an engine of a similar 
power of English make using Mond gas. 
The twentieth century opens with the gas-en- 
gine for the first time in its century of evolu- 
tion seriously competing with the steam-engine 
in important commercial work on a large scale. 
“R. H. THurRSTON. 
THE U. S. GEOLOGICAL SURVEY. 
For the support of the U. S. Geologial Sur- 
vey for the fiscal year ending June 30, 1902, 
Congress appropriated at the session just closed 
about $1,018,000, an increase of $52,000 or more 
over the present year’s appropriation. In- 
deed, there was a strong disposition in Congress. 
to make a material increase, notably for the ex- 
tension of hydrographic investigations. 
Of the several sums appropriated $250,000 
is for the topographic surveys, including a re- 
port on the topography and geology of the 
territory adjacent to the 49th Parallel, west 
of the 110th Meridian. For the survey of the 
forest reserves there is $130,000, the same as the 
present year. For geologic surveys the amount 
is $150,000—no increase—and for the continu- 
ation of the investigation of the mineral re- 
sources of Alaska, $60,000. For paleontologic 
researches there is $10,000. For chemical and 
physical researches relating to the geology of 
the United States there is granted $20,000, being 
$10,000 more than the sum appropriated for the 
present year. The increase will enable the 
Director to carry on needful and long neglected 
physical researches in connection with the 
chemical work of the Survey. For want of 
funds the Survey has had no physical laboratory 
for some years. 
For the collection of data and the prepara- 
tion of a report on the mineral resources of the 
