HEAT FROM SMALL CYLINDERS IN A STREAM OF FLUID. 
421 
Description of Tables V. and VI.—Analysis of the Convection Constants B and C. 
In Tables V. and VI. are summarised the results of the entire series of observations on the ten 
specimens of platinum wire. The measurement of the diameters and the calculation of the temperature of 
the wires have already been described in Sections 10 and 11. In the case of each wire the constants 
B and C of the formula W = B JV + C were determined from the position of the lines of closest fit to the 
observed points illustrated in figs. 4 and 5. 
In Table V. the constant B is printed in heavy-faced type and beneath it in italics the ratio 
/3 = B/((9- 6f). The variation of B with temperature is illustrated for each wire by the graphs of fig. 6. 
The constant /3 increases slightly with the temperature in the manner indicated by the formula 
A= A [1 + b (6 - 0 O )]- The constants /3 0 and b were determined graphically by plotting /3 against (0 - 6 0 ). 
Finally the ratio f3 0 / Ja was found to be very nearly constant in the case of each wire as shown in the 
grajih of fig. 7, and its mean value is seen to be in fair agreement with that calculated from the theoretical 
investigation of Part I. 
Table VI. contains the analysis of the constant C. The part of this term due to radiation is calculated 
in the manner described in Section 13, making use of the observations of Lummer and Kurlbaum. In 
heavy-faced type are given the values of Co = C-E and beneath it, in italics, the ratios y = Gq/(0 - 6 0 ), 
which it will be seen vary comparatively slowly with temperature and radius. For each wire the 
constants y 0 and c of the formula y = y 0 [1 + c (6 - (9 0 )] were determined graphically. The constant y 0 
varies slightly with the radius and its value is not far removed from that required by the theory of 
Section 6. The value of y 0 for Wire No. 2 shows a discrepancy which was explained, on microscopic 
observation, as due to the fact that owing to the use of an imperfect die the wire was badly scored along 
its length. 
O 
