Constant Current Type of Hot- Wire Anemometer. 721 



accompanied its rotation through successive angles from the 

 horizontal to the vertical position. The magnitude of 

 these variations when heating currents of from 0*9 to 1*5 

 amp. were employed will be seen from fig. 2, wherein are 

 given the results for successive angles of inclination to the 

 horizontal increasing by 10°, readings in eacli case being 

 taken with the pointer indicating the same inclination to the 

 right and left of its initial vertical position. The initial 

 horizontal position of the exposed wire can be very accurately 



O 20 «30 SO 80 



"NCUNATEON OF WiSE TO H0RIZOMT/a.(&&28EE3) 



determined by employing the bridge as previously described. 

 It is clear that if the bridge is balanced with the wire either 

 horizontal or vertical, equal galvanometer deflexions are 

 obtained on rotation of the exposed wire through the same 

 angle in a clockwise or counter-clockwise direction. The 

 temperature of the surroundings varied from 1(>°C to 

 20 o, 8 C. while the results shown in fig. 2 were being obtained. 

 For the purposes of comparison it appeared desirable to 

 reduce the experimental results to a uniform basis in which 



