17 Drummond Place,
Saturday.
My dear Sir,
I have received your papers & will do what & when I can to bring them before the R.S.E. <1>
I have two remarks to make, but they must be very brief, as I find the difficulty of transferring my great battery, along with the delicate apparatus, and setting all up in the Society’s Room is much greater than I imagined.
1) As to your Case (2). It seems to me that your explanation is a sort of non-sequitur – for it by no means follows generally that the ray coming from glass through Canada balsam to spar will not be divided into two, both of which shall pass: although when rays enter by the spar only one passes, to the glass. For in the first case the rays enter parallel in the glass & may have great divergence in the spar. So that to exactly reverse the phenomenon you should send into the spar two different sets of parallel rays, and then (if these be properly chosen) you may get a common direction for the refracted ones.
I would rather put it thus: To get in to the glass, so as to get out by the spar, requires very different directions for the light furnishing the extraordinary & ordinary rays.
2) The other point is a delicate one, & I hope you will not be annoyed by my mentioning it, as I do it in no ways for myself but to help to secure for the University £1000 which Dr Neil Arnott <2> has placed in bank for us – but hesitates to give till he is sure that useful work is being done in the Laboratory. I am sure that if you were to say in your first note, “Many of these experiments were made in the Physical Laboratory of the University of Edinr”, such a clause (in which I do not at all appear) might help greatly to get us this Scholarship, which the Doctor is so tantalizingly holding before us. If we could get it, (& I have been doing all I can to secure it), it would greatly help the development of Physical Science here by giving many of our students the means of devoting part of their time to physical work instead of to teaching for a livelihood.
Yours truly
P.G.Tait.
Notes:
1. Royal Society of Edinburgh.
2. Neil Arnott (1788–1874), physician and inventor, was an Arbroath native and one of the founders of the University of London. In May 1869, the announcement was made that he had presented Edinburgh University £1000 "for founding an annual prize for the Encouragement of Study of Experimental Physics among the Medical Students of the University."