DEVELOPMENTS IN OIL BURNING. 261 



having been the maximum in those tests. In this we were assisted by the 

 fact of having available a strong closed fire-room draft and a powerful steam 

 jet in the stack. Much experimenting was, however, found necessary, almost 

 entirely in the direction of air admission and distribution, some two months 

 being devoted to preliminary trials of various forms of apparatus. 



Again the flat bladed impeller plate was found to be most suitable, a 

 number of different designs of this being tried out, among which may be 

 mentioned one having adjustable blades. 



Finally, with the grate bars in place, six burners and impellers were 

 installed, two in each fire door, and a test was made resulting in a combustion 

 of .72 pounds of oil per square foot of heating surface and 11.6 pounds 

 per cubic foot of furnace volume, a very distinct advance over the Idalia 

 performance. 



The grate bars were then removed, the ash pan fined with fire-brick, a 

 second row of burners installed below the first, and efforts to obtain still 

 higher capacities were continued. The experiments indicated that a con- 

 siderable number of smaller burners and impeller plates was preferable to a 

 few of larger size, and the furnace front was remodeled and fitted with eleven 

 cast-iron boxes 13 inches square, each carrying an impeller plate 8 inches in 

 diameter and each arranged to receive a burner. With nine of these burners 

 in operation an evaporization of 13.16 pounds of water per hour from and 

 at 212° per square foot of heating surface was obtained, burning .85 pound of 

 oil per square foot. Results of tests indicating the progress of this prelimi- 

 nary work are shown in Table III. 



These figures seemed to warrant our requesting that a board of naval 

 officers be appointed to witness and supervise further tests. There was no 

 guarantee connected with the matter, but we were desirous of demonstrating 

 to the Navy Department what could be done with our apparatus, and also 

 particularly to have the results checked by competent and thoroughly dis- 

 interested observers who should secure sufficient authentic data to place the 

 final figures absolutely above criticism. It seems unfortunate that this plan 

 is not more frequently followed as ex parte tests are always open to doubt, 

 especially when the results are unusual. 



Official Tests with Oil Fuel. — The following extract is from the beginning 

 of the Board's report: 



"This test was conducted by a Board composed of Captain C. A. Carr, 

 U. S. N., and Lieutenant-Commanders J. K. Robison and John Halligan, 

 Jr., U. S. N. 



"The Board assembled at the works of The Babcock & Wilcox Company, 

 Bayonne, N. J., about 10 A. M., November 28, 1910. The Board examined 



