66 PETER GUTHRIE TAIT 



Towards the close of Tail's sojourn in Belfast, Andrews was preparing to 

 attack the problem of the compressibility of gases. In this research Tait was 

 to join him; but his election to the Chair of Natural Philosophy in Edinburgh 

 altered all these plans. 



The duties of his new Chair compelled him to give still more attention to 

 the experimental than to the mathematical side of Natural Philosophy. In 

 the early years he devoted much time to the preparation of his lectures and 

 lecture experiments. In arranging the experimental illustrations he had the 

 able help of James Lindsay who had served both Sir John Leslie and Professor 

 Forbes as mechanical assistant. His scientific activities are clearly displayed 

 in his letters to Andrews ; and from these a few quotations will show how this 

 kind of work grew upon his hands. A long extract referring to his first 

 lecture has already been given (page 22). On December i, 1860, Tait 

 wrote : 



My dear Andrews, 



I am very much obliged to you for your note to Faraday. I enclosed 

 it in a letter to him, telling him that I wished to ask his opinion on a point in the 

 optical effects of magnetism ; and as I sent him a copy of my lecture 1 I ventured 

 to ask him to inform me at his leisure whether I had in it fairly stated the case 

 at issue between him and the pure mathematicians about conservation of force. 

 I got a very kind answer yesterday. He requests me to postpone my question (if a 

 difficult one, and it is so) till after Christmas but about the other matter he says 

 " I thank you for the way in which you have put the Gravitation case. It is just 

 what I mean." He says he has been working at it all summer, but still with 

 negative results and that he had drawn up a new paper for the Royal Society, but 

 that Stokes had advised him not to present it... 



COLLEGE, EDINBURGH, 



Jan. 29, 1 86 1. 

 My dear Andrews, 



I would have written to you sooner, had not my hands been full of the January 



Examinations, and some experiments which Principal Forbes asked me to make 



In a paper which is I believe to appear in the Phil. Mag. for February, and which 

 was read some weeks ago at the R. S. E., he states that few people living have ever 

 seen Ampere's experiments for the repulsion of a current on itself and that he had 

 never succeeded in getting it. At his request I tried it, and succeeded with a single 

 cell of Grove's battery. With twelve cells the floating wire almost jumped out of the 

 trough ! As there is some slight objection to this form of the experiment on account 

 of the thermoelectric effects which occur at every change of metal in the circuit, 



1 This refers to Tail's inaugural lecture, in which he discussed Faraday's attempts to demonstrate 

 the Conservation of Force in the sense of attraction. 



