PRESIDENTIAL ADDRESS. ]1 
just been tested by Professor Goodman for the New South 
Wales Government. Saturated steam was used at 57 Ibs. 
pressure per square inch, giving a steam consumption of 
27°93 ibs. per water horse power hour. The turbine required 
15°6 tbs. of steam per brake H.P., so that the combined 
efficiency of the pumps was 56%. The pumps were tested 
against a total head of from 744 to 762 feet, and the water 
horse power was 235 to 252. The speed of the turbine was 
3,200 revolutions per minute. Similar satisfactory tests 
were made with steam superheated to 95° F. 
The steam engine has through nearly two centuries of 
continued improvement reached the zenith of its career of 
usefulness, and is in danger of displacement by either one 
or both of its two thermodynamic superiors, the steam 
turbine and the gas engine. | 
Steam Boilers.—Recent progress in steam boiler con- 
struction consists mainly in the perfection of details in 
design to meet the severe conditions of modern practice. 
Horizontal return multi-tubular boilers are probably still 
the most widely used type to-day; they give a high 
efficiency and are of comparatively low cost, although 
their use is confined to the smaller plants as they are of 
limited size for high pressures. The use of water tube 
boilers is rapidly increasing, as they are adapted to large 
plants, and high pressures, danger from explosion being 
reduced to a minimum. The Manhattan Railway power 
_ house, New York City, contains 64 water tube boilers rated 
at over 500 horse power each, or a total of 32,000 horse 
power. Economy of labour and fuel has been considerably 
increased by the use of mechanical stokers, coal and ash 
handling machinery. 
Considerable attention has been recently given to the 
use of water tube boilers in the Navy, and the extensive 
experiments made by the Admiralty on different steam 
