Glenlair, 26th April 1848.

 . . . On Saturday, the natural philosophers ran up Arthur's Seat with the barometer. The Professor set it up at the   top and let us pant at it till it ran down with drops. He did not set it straight, and made the hill grow fifty feet: but  we got it down again.
We came here on Wednesday by Caledonian. I intend to open my classes next week after the business is over. I   have been reading Xenophon's Memorabilia after breakfast; also a French collection book. This from 9 to 11.   Then a game of the Devil, of whom there is a duality and a quaternity of sticks, so that I can play either conjunctly   or severally. I can jump over him and bring him round without leaving go the sticks. I can also keep him up behind  me.

 Then I go in again to science, of which I have only just got the books by the carrier. Hitherto I have done a prop   on the slate on polarised light. Of props I have done several.

     1. Found the equation to a square.
     2. The curve which Sir David Brewster sees when he squints at a wall.
     3. A property of the parabola.
     4. The same of the Ellipse and Hyperbola....

I can polarise light now by reflection or refraction in 4 ways, and get beautiful but evanescent figures in plate glass by heating its edge. I have not yet unannealed any glass....

I don't understand how you mug straight on. I suit any muggery to my temper that day. When I am deep I   read Xenophon's defence of ; when not I read 's  witty dialogues. If I do not do this, I always find myself   reading Greek, that is, reading the words with all their contractions, as a Jew reads Hebrew. I get on very    rapidly, but know nothing about the meaning, and do not even know but that I am really translating.

Please to write about your Prizes at College, and about coming here to mug? You must learn the D——1.

     Tatties is planting.—Yours, etc.