500 Proceedings of Royal Society of Edinburgh. 
right. Clerk Maxwell, then a rising star of the first magnitude in 
our eyes, was too young to appear on the list. 
About 1878 we got to the end of our “Division II.” on 
“ Abstract Dynamics ” ; and, according to our initial programme, 
should then have gone on to “properties of matter,” “heat,” 
“light,” “electricity,” “magnetism.” Instead of this we agreed 
that for the future we could each work more conveniently and on 
more varied subjects, without the constraint of joint effort to 
produce as much as we could of an all-comprehensive text-book of 
Natural Philosophy. Thus our book came to an end with only a 
foundation laid for our originally intended structure. 
Tait’s first published work was undertaken in conjunction with a 
Peterhouse friend, Steele, who was his second in the University 
both as Wrangler and Smith’s Prizeman. They commenced their 
work together immediately after taking their degrees ; hut Steele 
died before more than two or three chapters had been written, and 
Tait finished it alone, and published it four years later under the 
title “ Tait and Steele’s Dynamics of a Particle” (1856). It has 
gone through many editions, and still holds its place as a text-book. 
Tait’s second published book, “ Elements of Quaternions,” was 
commenced under the auspices of Hamilton ; but, in deference to 
his wish, not published till 1867. It has gone through three 
editions, and is, I believe, the text-book for all those who wish 
to learn the subject. 
Tait also produced several valuable Treatises , short, readable , 
interesting, and useful, on various subjects in physical science : — 
“ Sketch of Thermodynamics ” (1867). 
“Recent Advances in Physical Science ” (1876). 
“Heat” (1884, 2nd edition 1892). 
“Light” (1884, 3rd edition 1900), based on article in Ency- 
clopaedia Britannica. 
“Properties of Matter” (1885, 4th edition 1899). 
“Dynamics” (1895), based on article “Mechanics” in Ency . 
Brit. 
Among smaller articles contributed to the Ency. Brit, are 
“ Quaternions,” “ Radiation and Convection,” and “ Thermo- 
dynamics,” all reprinted in the collected papers. A small 50-page 
book on “ Newton’s Laws of Motion ” is a remarkably concise 
