RECENT ADVANCE IN OIL BURNING. 159 
requirements, the same procedure and methods of testing were followed as are 
customary on an official series. 
“Yours very truly, 
“(Signed) W. R. PURNELL, 
“Tieutenant Commander, U. S. N.” 
It is but fair to say that this rather remarkable capacity test was in a measure 
unexpected, as the original intention was to burn 1,500 pounds of oil per hour per 
burner. Also, while the boiler and furnace efficiency is low compared to results 
in the White-Forster tests, the results are better than the previous record on the 
Normand boiler as reported by Lieut. Commander (now Captain) John J. Hyland, 
formerly in command of the Testing Plant. Thus at the rate of .455 pound of 
oil per square foot of heating surface per hour the previous efficiency result was 
74.5 per cent, while the present record is 80.67 per cent. No test was run pre- 
viously at a rate higher than 1.05 pounds of oil per square foot of heating surface 
per hour, but the efficiency curve extended to the 1.2 pounds mark shows 64.5 
per cent, while the present record is 68.84 per cent. 
A new record in oil per burner per hour was established on September 17 by 
Commander Purnell when three of the six Babcock and Wilcox units were tested, 
the burners being supplied with larger tips. The oil used was 19.9 Baumé. The 
test was of one hour duration but followed several hours’ steaming during which the 
individual burner capacity was pushed up to 2,000 pounds per hour. The record 
for the hour shows 2,238 pounds, while in the last half-hour the rate of combustion 
per burner reached 2,287, a safe margin over one ton of oil per burner per hour. 
Owing to the three burners only being in operation in the large furnace it is 
to be noted that the oil burned per cubic foot of furnace volume was reduced to 
8.9 pounds per hour. 
I am again indebted to the Navy Department for permission to publish these 
remarkable tests (see Table III, Plate 67). The privilege is especially appreciated 
for the reason that the official report has not yet been completed. 
These tests are so very recent that it is not yet possible to foretell their precise 
significance, but it is worthy of note that six months ago fifteen burners were being 
considered for each of the sixteen boilers of the battle cruisers now being laid down. 
On the basis of this last performance only five would be required, and seven would 
be a safe estimate. To develop 180,000 horse-power with 80 or even 112 oil burners 
is a very notable performance, but there can be no doubt about its being entirely 
possible with the equipment which has been perfected in this country. We shall 
no doubt hear the time-honored warning against putting too many eggs in one 
basket, but nevertheless I am convinced that the large unit, both in boilers and 
oil burners, has come to stay, particularly if it carries with it efficiency, accessibility, 
simplicity, safety and flexibility, which it most assuredly does. 
I do not wish to be understood as saying that I think that oil burners atomizing 
a ton of oil per burner per hour will be immediately adopted for naval service, 
far less for the merchant marine, but the trend of modern development is certainly 
