312 



MR. N. BOHR ON THE DETERMINATION OF THE 



By introducing the values for //,, p, c, a, and k, which correspond to the experiments 

 carried out, this correction becomes very small, about O'l per cent.* 



As to the calculated correction for the influence of the finite wave-amplitudes, it 

 may be mentioned that the values of the surface-tension in the table of the experiments 

 on p. 313, which has been calculated according to the formula (37) on p. 296, does 

 not show any systematic deviation due to the wave-amplitude. 



As, however, the correction for the value of the wave-amplitude in the experiments 

 carried out is rather small (from O'lO per cent, to 0'33 per cent.), the agreement 

 mentioned is not adapted to give an experimental verification of the formula 

 theoretically developed. It may here be remarked that P. O. PEDERSEN (loc. cit., 

 p. 371) has experimentally investigated the influence of the value of the wave- 

 amplitudes upon the calculated values of the surface-tension and has found results, by 

 using greater wave-amplitudes, which can be shown to be in very good agreement 

 with the formula in question. 



In the other experiments the wave-length was measured only on a shorter jet-piece, 

 which, however, was so far from the orifice that the value of the wave-lengths had 

 become constant. 



As an example of such a measurement, an experiment with tube I may be mentioned, 

 which was carried out with a pressure-height of about 70 cm. 



In the table below are quoted two sets of readings, obtained in succession, with 

 their differences. 



The horizontal place of the jet was at a distance of 21 '5 cm. from the orifice, which 

 corresponded to a reading on the glass-rule of 7 '5 cm. Corrections of the readings 



* The smallness of the correction is due to the email coefficient of viscosity (/* = 0-0125) and the great 

 surface-tension (T = 74) of water. The correction mentioned can, however, become quite considerable for 

 liquids in which these quantities have other values ; if, for example, aniline (p = 062, T = 44) was 

 used, the correction would have been more than 1 per cent, by corresponding experiments. 



