22 PETER GUTHRIE TAIT 



to year. For certain parts he had a particular affection, such as, applications 

 of Fourier analysis, Green's theorem, and especially the theory of strains. 

 The last named was, indeed, a subject peculiarly his own, and many of 

 his demonstrations, although given in ordinary Cartesian coordinates, were 

 suggested by the quaternion mode of attack. 



An important feature of the Natural Philosophy Department since 1868 

 was the Physical Laboratory, for which Tait had secured a money grant as 

 early as April 1867 but was unable at the time to find accommodation 1 . 

 Lying quite outside any recognised course of study this purely voluntary 

 course of practical physics offered no inducement to the ordinary student 

 intent on getting his Degree. Tail's idea was to attract men who wished 

 to familiarise themselves with methods of research. This he did by giving 

 every encouragement to the man who had thought of some physical question 

 worthy of investigation, or (as was more frequent) by suggesting some line 

 of research to the eager student. Whoever showed real aptitude had all 

 the resources of the Department placed at his disposal ; and beyond the 

 initial fee of two guineas for the first winter session no other charge was 

 made, no matter how long the student continued to work in the laboratory. 

 Those students whose interest in the subject brought them back after the 

 first session of their enrolment, were nicknamed "veterans"; and on their 

 enthusiastic help Tait largely depended for the successful carrying out of 

 his many ideas. This will be brought out in Chapter II on Tail's 

 Experimental Work. 



Having given a broad outline of Tail's method of instruction I propose 

 now to sketch briefly the main scientific events of his life, the more important 

 of which will, however, be discussed in detail in later chapters. 



On taking up the duties of the Edinburgh Chair Tait gave his first 

 care to the preparation of his class lectures ; and we get glimpses of the early 

 development of his ideas from his letters to Andrews, for access to which 

 I am indebted to the kindness of the Misses Andrews. 



The following is his own description of his first lecture given on 

 November 5, 1860. 



"The Lecture (that is, the formal inaugural lecture) has not yet appeared in 

 public. I began to-day, but, fancying that a dry technical lecture to commence with 

 might perhaps keep off rather than attract amateur students, I gave a set of 



' Thomson's laboratory in Glasgow began about 1850; and Carey Foster's in University 

 College, London, was established in 1866. 



