AND MODERN* PHYSICS. 23 



gentle and simple in exactly the same tone. On the other 

 hand, hi* teachers Forles above all had formed the highest 

 opinion of his intellectual originality and force ; and a few 

 exjicrieiiced observers, in watching his devotion to his father, 

 began to have some inkling of his heroic singleness of heart. 

 To his college companions, whom lie could now select at will, 

 his quaint humour was an endless delight. His chief associates, 

 after I went to the University of Glasgow, were my brother, 

 Itotart Campbell (still at the Academy), P. G. Tait, and Allan 

 Stewart. Tait went to Peterhouse, Cambridge, in 1848, after 

 one session of the University of Edinburgh ; Stewart to the 

 same college in 1840 ; Maxwell did not go up until 18.V)." 



During this period he wrote two important papers. 

 The one, on " Rolling Curves," was read to the 

 lloyal Society of Edinburgh by Professor Kelland 

 (" it was not thought proper for a .boy in a round 

 jacket to mount the rostrum") in February, 1849; 

 the other, on "The Equilibrium of Elastic Solids," 

 appeared in the spring of 1850. 



The vacations were spent at Glcnlair, and we learn 

 from letters to Professor Campbell and others how 

 the time was passed. 



" On Saturday," he writes* April 2Gth, 1848, just 

 after his arrival home "the natural philosophers 

 ran up Arthur's Seat with the barometer. The 

 Professor set it down at the top. ... He did not 

 set it straight, and made the hill grow fifty feet; but 

 ' we got it down again." 



In a letter of July in the same year he describes 

 his laboratory : 



" I have regularly Ret up shop now above the wash -house 

 at the gate, in a garret. I have an old door set on two barrels, 



* " Lifn of J. C. Maxwell," p. 11C. 



