MAXWELL ON SPHERICAL HARMONICS 101 



It seems to have little or nothing to do with your 4nionic reduction which 

 is of course indept. of a selected axis 1 . 



My method is also indept. of a selected axis, but does not seem to be 

 equivalent to your 4nion reduction which goes by steps. 



Murphy is not at all bad in his way and affords a very good specimen of a 

 Caius man working a calculation. 



How is it that 1,<f>ap^ can be worked only at Caius ? See Murphy, Green, 

 O'Brien, Pratt. When I examined here the only men who could do figure of the 

 earth were mild Caius men. All the rest were Prattists if anything. 



I think a very little mortar would make a desirable edifice out of your article. 



In selecting the absolute value of the constant coefficient of a harmonic we may 

 go on one of several principles. 



There then followed a comparison of his own expressions with the cor- 

 responding expressions used by T and T' and by Tait. He continued : 



The great thing is to avoid confusion. I rather think your value is the best 

 to impress on the mind. It lies between it and ^ (8) which has a certain claim. 



The diggings in 2<ap are very rich and a judicious man might get up a 

 capital book for Cambridge, in which the wranglers would lade themselves with 

 thick clay till they became blind to the concrete. 



But try and do the 4nions. The unbelievers are rampant. They say "show 

 me something done by 4nions which has not been done by old plans. At the 

 best it must rank with abbreviated notations." 



You should reply to this, no doubt you will. 



But the virtue of the 4nions lies not so much as yet in solving hard 

 questions, as in enabling us to see the meaning of the question and of its solution, 

 instead of setting up the question in x y z, sending it to the analytical engine, and 

 when the solution is sent home translating it back from x y z so that it may 

 appear as A, B, C to the vulgar. 



There appears to be a desire for thermodynamics in these regions more than 

 I expected, but there are some very good men to be found. 



You will observe a tendency to bosch in this letter which pray xqs as I 

 have been reading an ill assorted lot of books till I cannot correct prooves. 



yours truly 



d> 

 dt ' 



1 Nevertheless Tait says in his paper that he was led to the method while engaged in 

 some quaternionic researches. 



2 j-=JCM, (Maxwell's initials), one expression for the Second Law of Thermodynamics, 



as used by Thomson in his early papers, and by Tait in his Historic Sketch, J being Joule's 

 equivalent, C Carnot's function, and M the rate at which heat must be supplied per unit 

 increase of volume, the temperature being constant. 



