96 PETER GUTHRIE TAIT 



students of whom Tait made use. Others, however, are equally worthy of 

 mention. Thus the compression work with the " Big Gun " owed much of 

 its success to the labours of R. T. Omond, afterwards superintendent of the 

 Ben Nevis Observatory, and H. N. Dickson, at present Lecturer on Geography 

 in University College, Reading. Again it was largely through the exertions 

 of A. J. Herbertson, now Reader in Geography, Oxford University, and 

 R. Turnbull, now Inspector, Department of Agriculture, Dublin, that the 

 impact apparatus evolved itself from the first rude form to the final perfected 

 arrangement ; and the later set of experiments and their reductions were 

 practically carried out by Alexander Shand. 



It is interesting to note that many of Tail's students who helped him in 

 research work did not become professional physicists. Under the old system, 

 which present day pigeon-hole organisers rather despise, men had time to put 

 in valuable work which lay outside their official course of study. Tait and 

 his assistants soon saw who were the more resourceful among the laboratory 

 students, and these were quickly enrolled in the unofficial squadron of workers. 

 Under the present system of detailed courses of obligatory work, carefully 

 scheduled for the benefit of the average student, such a method as Tait 

 commanded in his day could hardly be applied. Many more students are 

 trained now than formerly to make physical measurements ; and the training 

 is more systematic and thorough ; but, with the exception of those who expect 

 to follow out physics in their life career, very few ever come in touch with the 

 stimulus which real research work gives. The day apparently is past for 

 fruitful physical work to be effected in their student days by men who 

 afterwards become clergymen, physicians, geographers, botanists, zoologists, 

 or even engineers. 



This account of Tait as an experimental philosopher would not be com- 

 plete without some reference to the encouragement he gave to any of his 

 students following out researches of their own, which had not been directly 

 suggested by him. In particular, to those of us who desired to prepare an 

 experimental thesis for the Doctorate in science, he gave every facility in the 

 way of accommodation and apparatus. Among the more extended investiga- 

 tions of this independent nature I might mention Ewing and MacGregor's 

 measurement of the electric conductivity of saline solutions, Macfarlane's 

 experiments on the electric discharge through air and other dielectrics, my 

 own work on contact electricity, Crichton Mitchell's study of the rate of 



