150 
was first when running to enter the undisturbed air. The action of the 
air currents upon it, therefore, was in every way similar to those affecting 
an engine doing ordinary work at the head of a train. 
The boiler of the experimental locomotive was kept under a steam 
pressure of 150 pounds by a supply of steam drawn from the boiler of the 
normal engine in the rear. There was no fire in the experimental boiler, 
which at all times was practically void of water. Precautions were taken 
which justified the assumption that all water of condensation collecting 
in the experimental boiler was the result of radiation of heat from its 
exterior surface. This water of condensation was collected and weighed, 
thus serving as a means from which to calculate the amount of heat radi- 
ated. 
The dimensions of the experimental boiler are shown by Table I: 
TABLE I. 
Dimensions of Boiler. 
PpaMeters inl CHES! fs ey pein b-cistee betas dele eatavale ata tomy ciate selene 52 
Heating surface: (Sqttare feet). ccs ciciec ccs owe calsictee, crate 1,391 
Total area of exterior surface, not including surface of 
RIO eee MOE. Si cesisectds seer eee nies eee ales Steere sis o Gistanee stceuats \é 358 
Area of surface, covered (square feet) 2... ews cece wales 219 
Area of steam heated exposed surface not covered........ 139 
Ratio of surface covered to total surface................. 61 
The results of the tests, briefly stated, are shown in Table II: 
TABLE II. 
Pounds of Steam at 150 Pounds Pressure Condensed per Minute. 
Bare: belleriat Test... toeh a oe eee seiner ses Meee ete 6.8 
UST Nach ays fos oin wis ea laze edetataie ote tete a viele tecs cle tele ane, aie tisuate ere omen tems 14.3 
Boiler covered in the usual way with approved material— 
61 per cent. of the total surface only being protected—at 
TM Se eye as aistetnelevsia salolererate-d ie air \sis a stx'eys tines onaetsl eae a at sche 3.0 
Boiler covered in the usual way with approved material— 
61 per cent. of the total surface only being protected— 
moving at a uniform speed of 28.3 miles per hour ....... 5.38 
