tunity Wallace, whose circumstances were those of a straitened journeyman
worked hard at his trade during a portion of the time that should have been
devoted to sleep Here, too, Dr. Robison's kind patronage did not terminate
for he introduced his protege to Professor Playfair, who lent him scientific
books, and gave him valuable suggestions for the study of the higher branches
of mathematics. Dr. Robison also intrusted him with the tuition of one of his
own pupils in geometry—a useful training to William Wallace, for the important charges as a public instructor, which he afterwards occupied.
Finding that the trade to which he had served a regular apprenticeship afforded too little time for study, and that he might advance himself to something better, Wallace became a warehouseman in a printing-office, where his opportunities of acquiring knowledge were more abundant. Here he mastered the difficulties of the Latin language by his own industry, aided by a few lessons from a college student, and afterwards studied French. He then exchanged the printing-office for the situation of shopman to one of the principal booksellers of Edinburgh—and approaching still nearer to the ultimate mark, he devoted his evenings to the teaching of mathematics as a private tutor. As this last occupation was more congenial than the other, he devoted himself to it entirely, having abandoned the shop for that purpose ; and a short time afterwards he was appointed assistant teacher of mathematics in the academy of Perth. This was in 1794, when he had attained his twenty-sixth year, and acquired such a reputation that the most scientific men in Edinburgh welcomed him as a brother. Soon after he had settled in Perth he married, and for nine years after there was a lull in his hitherto changeable course, during which he quietly discharged the duties of his somewhat obscure and humble calling. But the time thus spent was not spent in idleness, as he evinced when the fitting season arrived; and among the fruits of his studies at Perth, were three articles, which successively appeared in the respective publications for which they were intended. The first, which was presented to the Royal Society of Edinburgh in 1796, was entitled "Geometrical Porisms, with Examples of their Applications to the Solution of Problems." About the same period he contributed the article "Porism" to the third edition of the "Encyclopædia Britannica." His third article, which he presented to the Royal Society of Edinburgh, contained a new method of expressing the co-efficients in the development of the formula that represents the mutual perturbation of two planets; to which was added an appendix, giving a quickly converging series for the rectification of an ellipse. The scientific men who were qualified to judge of these papers bore high testimony to their accuracy and originality.
The time at length arrived when Mr. Wallace was to be elevated to a more fitting sphere of action. From the obscurity of such a town as Perth, his reputation had so widely diffused itself, that in 1803 he was invited to stand as candidate for the office of mathematical master in the Royal Military College, lately established at Great Marlow, in Buckinghamshire. He consented, moved to this by the advice of his venerated friend, Professor Playfair; and in the examination of candidates, his qualifications were found so much superior, that he was immediately elected to the office. It is interesting to notice that, in the following year, his countryman, Mr. Ivory, who, like himself, had been the subject of struggle and change, and who had also fought his way to scientific reputation, was elected to the professorship of mathematics in the same college. On the removal of the institution to Sandhurst, in Berkshire, Mr. Wallace
