90 PETER GUTHRIE TAIT 



with a speed of not more than 300 feet per second. Assuming 2/3 as the 

 coefficient of restitution, Tait found that the head of the club must have been 

 travelling at the rate of about 200 feet per second at the instant of impact. 

 Other questions relating to the flight of the golf ball have been already 

 discussed in Chapter i. ; and Tait's own final views will be found below in 

 his article on Long Driving, which appeared in the Badminton Magazine. 



With a mind always on the alert for scientific problems, it is not surprising 

 that Tait occasionally failed to find what he was in search of. His attempts 

 to obtain distinct evidence of the Thomson Effect in thermo-electricity have 

 already been noted ; and I remember him spending the better part of a summer 

 session in the experimental study of electrification due to sudden evaporation 

 or condensation. Morning after morning he would come with a new arrange- 

 ment to try, meeting my enquiry with the remark, " Now, at last, I have got 

 the crucial experiment." He devised for this research large flat metallic 

 dishes, which we facetiously dubbed " frying pans " ; but nothing came of 

 it. Tait's conclusion was that his surfaces were not big enough. 



Another enquiry which occupied his mind at intervals from his Belfast 

 days was the possibility of doubling an absorption line through the influence 

 of magnetism. That such an effect should take place was an inference he 

 made from Faraday's discovery of the rotation of the plane of polarization in 

 a strong magnetic field. In a short paper read before the Royal Society of 

 Edinburgh in 1876 he gave briefly the grounds for his belief (Set. Pap. 

 Vol. i, p. 255). With more powerful magnetic fields than were at that time 

 available there is little doubt that he would have observed an effect of the 

 kind looked for, and thus anticipated Zeeman's closely allied discovery of 1896. 



"In consequence of the severe lightning stroke with which Skerry vore 

 Lighthouse was visited on 2nd February 1876, occasioning considerable 

 disturbance to the internal fittings of the lighthouse and the destruction of the 

 entrance door," D. and T. Stevenson, Engineers to the Board of Com- 

 missioners of the Northern Lights, suggested "the propriety of consulting 

 Professor Tait on the general question of protecting the lighthouse towers 

 against the effects of lightning." Professor Tait accordingly accompanied 

 David Stevenson and others of the Commissioners on their annual visitation 

 during the ensuing summer, and his opinions and advice are given in the 

 Report, of which the opening sentences have just been quoted. During this 

 trip of inspection Tait's attention was drawn to the methods of producing 

 fog signals, and experiments were afterwards made in Edinburgh to test the 



