1024 On the Measurement of Absolute Viscosity. 



solution is given in my memoir published in French {Annates 

 ties ponts et chaussees, 1913, Fuse, iii.-v.). There are given 

 the numerical tables, which enable us to calculate very easily 

 I girders under different conditions o£ loading and fastening 

 of the ends. 

 70 Sinclair Ed., W. 17. Yours truly, 



August 30, 1921. S. TlMOSHENKO. 



CVTII. Notes on the Measurement of Absolute Viscosity. 



To the Editors of the Philosophical Magazine. 

 Gentlemen, 



SINCE the publication of my paper " Notes on the Mea- 

 surement of Absolute Viscosity " in the February 

 number of this Magazine, my attention has been drawn 

 to the fact that the variable head correction had already 

 been noticed by Meissner [Chem. Rev. uber die Fett ty Hartz 

 Industrie, vol. xvii. p. 202, 1910), by Simeon (Phil. Mag. 

 xxvii. p. 38, 1914), and by Bingham, Schlessinger, and 

 Coleman (Journ. Amer. Chem. Soc. 1916, p. 27) ; also the 

 value of unity for the kinetic energy coefficient was found 

 by Couette and Finkener, and again by Kohlrausch (Lehrbuch 

 der Prahtischen Physik, p. 258, 11th edition, 1910). 



I can only say that for my own part the work in my 

 paper was entirely original, and I had no idea the ground 

 had been covered before, all of which, of course, only serves 

 to emphasize the necessity of keeping in touch with current 

 literature. 



Yours faithfully, 



Derby, March 31st, 1922. Frank M. LlDSTONE. 



CIX. Intelligence and Miscellaneous Articles. 



ON THE MEASUREMENT OF ABSOLUTE VISCOSITY. 



To the Editors of the Philosophical Magazine. 



Deae Sies, — 



IVTAY I point out with reference to the paper by Mr. Lidstone 



■^■*- in the February number of the Philosophical Magazine, 



p. 354, that the equation deduced there for the viscosity of a liquid 



can only be used it' the flow is from a uniform tube on the " high " 



side of the capillary tube to a uniform tube (not necessarily of the 



same bore as the other uniform tube) on the "low" side of the 



capillary tube. 



I am, 

 University of Toronto, Yours truly, 



Physics Dept. John SATTEELY_ 



April 7, 1922. 



