THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



NO V EMBER 1893. 



XLII. New Methods of Measuring the Surf ace-Tension of 

 Liquids. By T. Proctor Hall *. 



I. Historical. 



THE common way of measuring the surface-tension of 

 liquids by finding the height to which they will rise in 

 capillary tubes is simple and convenient, and is applicable to 

 nearly all liquids. The degree of accuracy attainable is 

 limited by (a) the narrowness of the tube, or else the short- 

 ness of the elevated liquid column, which limits the accuracy 

 of measurement ; by (b) irregularities in the bore of the tube ; 

 by (c) the difficulty in securing a clean surface, particularly 

 in very small tubes ; and by (d) impurities, such as dissolved 

 air, in the body of the liquid. It is to the last two causes 

 that most of the differences seen in the following table are 

 probably due. The table gives the values of the surface- 

 tension of water as found by various observers by means of 

 capillary tubes. All values are given in dynes per centimetre, 

 and the numbers in the second column are, where necessary, 

 deduced by Brunner's formula for the relation of surface- 

 tension to temperature. 



* Communicated by the Author. 

 Phil Mag. S. 5. Vol. 36. No. 222. Nov. 1893. 2 D 



