48 IOWA ACADEMY OF SCIENCE Vol. XXV, 1918 



Heat, pp. 542-3, Macmillan & Co., 1894. Ingersoll & Zobel, Mathematical 

 Theory of Heat Conduction, pp. 9-14. Ginn & Co. 



2* 2*:4' 2*-4*-6* 



See Byerly, an Elementary Treatise on Fourier's Series, etc., p. 219. 



5. Byerly, 1. c, p. 286. 



6. Byerly, Harmonic Functions, p. 218. (Edited by Merriam & 

 Woodward.) Published by Wiley & Sons. 



Byerly, Introduction to the Theory of Fourier's Series, etc., p. 39. 



Physics Department, 

 State College, 



