302 JAMES CLERK MAXWELL. [CHAP. X. 



of certain truths, and a leaning upon feigned experiments 

 instead of them. But this is exactly the place where the 

 students trust most to the professor, so that I care less about 

 it. I shall adopt the Optics, which have no such defect, and 

 possibly the Mechanics, next year. 



My students of last year, to the number of about fourteen, 

 form a voluntary class, and continue their studies. We went 

 through. Newton i. ii. iii., and took a rough view of the Lunar 

 Theory, and of the present state of Astronomy. Then we 

 have taken up Magnetism and Electricity, static and current, 

 and now we are at Electro-magnetism and Ampere's Laws. 

 I intend to make Faraday's book the backbone of all the rest, 

 as he himself. is the nucleus of everything electric since 1830. 



So much for class work. Saturn's Eings are going on 

 still, but this month I am clearing out some spare time to 

 work them in. I have got up a model to show the motions 

 of a ring, of satellites, a very neat piece of work, by Eamage, 

 the maker of the " top." 



For other things I have not much time in winter for 

 improving my mind. I have read Froude's History, Aurora 

 Leigh) and Hopkins's Essay on Geology, also Herschel's 

 collected Essays, which I like much, also Lavater's life and 

 Physiognomy, which has introduced me to him pleasantly 

 though verbosely. I like the man very much, quite apart 

 from his conclusions and dogmas. They are only results, 

 and far inferior to methods. But many of them are true if 

 properly understood and applied, and I suppose the rest are 

 worth respect as the statements of a truth-telling man. 



Well, work is good, and reading is good, but friends are 

 better. I have but a finite number of friends, and they are 

 dropping off, one here, one there. A few live and flourish. 

 Let it be long, and let us work while it is day, for the night 

 is coming, and work by day leads to rest by night. 



To EEV. LEWIS CAMPBELL. 



129 Union Street, 

 Aberdeen, 17th February 1858. 



... I have not been reading much of late. I have 



