TO LEWIS CAMPBELL, Esq.

In Kelland we find the value of expressions in numbers as fast as we can, the values of the letters being given; light     work. In Forbes we do Lever, which is all in Potter; no notes required, only read Pottery ware (light reading).    Logic needs long notes. On Monday, Wednesday, Friday, I read Newton's Fluxions in a sort of way, to know what I am about in doing a prop. There is no time of reading a book better than when you need it, and when you     are on the point of finding it out yourself if you were able.

TO LEWIS CAMPBELL, Esq.   31 Heriot Row, Novr. 1847.

As you say sir I have no idle time. I look over  notes and such like till 9.35, then I go to Coll., and I always   go one way and cross streets at the same places; then at 10 comes Kelland. He is telling us about arithmetic and    how the common rules are the best. At 11 there is Forbes, who has now finished introduction and properties of     bodies, and is beginning Mechanics in earnest. Then at 12, if it is fine, I perambulate the Meadows; if not, I go to     the Library and do references. At 1 go to Logic. Sir W. reads the first ½ of his lecture, and commits the rest to his     man, but reserves to himself the right of making remarks. To-day was examination day, and there was no lecture.     At 2 I go home and receive interim aliment, and do the needful in the way of business. Then I extend notes, and     read text-books, which are Kelland's Algebra and Potter's Mechanics. The latter is very trigonometrical, but not     deep; and the Trig. is not needed. I intend to read a few Greek and Latin beside. What books are you doing ? . . .
In Logic we sit in seats lettered according to name, and Sir W. takes and puts his hand into a jam pig full of   metal letters (very classical), and pulls one out and examines the bench of the letter. The Logic lectures are far the  most solid and take most notes.     Before I left home I found out a prop for Tait (P. G.); but he will not do it. It is "to find the algebraical equation to     a curve which is to be placed with its axis vertical, and a heavy body is to be put on any part of the curve, as on     an inclined plane, and the horizontal component of the force, by which it is actuated, is to vary as the nth power of     the perpendicular upon the axis."