HEAVY-OIL, ENGINES FOR MARINE PROPULSION. 243 
efficiency. With the proposed installation we would have a destroyer ready 
at a minute’s notice to proceed at full speed, with a complement one-half 
that now carried, with a radius under all conditions of from four to six times 
that which we now have, and with a total annual expense far less than that 
of any vessel of the same power in the Navy to-day. Instead of dwelling 
further on these advantages, the following table of actual figures, showing 
the difference between steam and oil engines, has been compiled: 
TABLE. 
Item. Steam. Oil. 
Miceated HOTSE=-POWEN. ..- oe. s sce ee FjfO0) an) 18,300 
PSHM PEM ORSE “POMEL. frcieraceyoicieaa aisieye olevs wise oe as 7,000 7,200 
Weight of main motive power machinery..... 449,522 317,000 
Weight per shaft, horse-power, pounds ....... 64 44 
Cruisingradiusat 16 knots with 180tonsfuel, miles 1,700 10,000 
Pounds fuel per horse-power-hour at 16 knots.. 3.0 0.60 
Cruising radius at 28 knots with 180 tons of fuel . 630 2,950 
Pounds, fuel per horse-power-hour at 28 knots. . Zan 0.50 
EB neineeh S LOrce TEquired <2)... eee ue ple eee 54 On 
Fuel consumed per annum 20,000 knots 
CUCUISITAS?, (HOSOI ON eena icy SRO ae ae ae 2,100 360 
Fuel consumed in port, tons................. 300 300 
Annual total fuel consumption, tons.......... 2,400 660 
Cost of fuel on’ Pacific Coast. 2.2.0 .6.5.. 2.6% $19,200 $4,620 
avg oteneineer Ss fOrCe pel Yeab 225) 0sc >... 22,500 9,600 
Nepairs, average atmtlaly. 2.5030. 6. ook oes 10,000 2,000 
In the foregoing the question of main motive power only has been 
considered. But, to make the vessel thoroughly comfortable and practic- 
able, certain auxiliaries have to be provided. The auxiliaries of the main 
engines are few and simple and as a rule are direct driven from the engines. 
There remains then only exterior needs to be provided for, such as cooling, 
heating, lighting, anchor hoist, steering engine, etc. One solution would be 
to provide a small donkey boiler using liquid fuel. Another, and more 
attractive solution, is to provide two auxiliary engines of 100 horse-power 
each. These would be direct connected to generators which would supply 
sufficient current for all purposes required. ‘This system would be quite 
efficient even taking into consideration the question of heating, and has 
much to recommend it in preferance to the donkey boiler. In extremely 
cold weather the heat obtained from the jackets and exhaust of the auxiliary 
