The Annual Biography and Obituary for the Year 1822
Vol. 6
London: printed for Longman, Hurst, Rees, Orme, and Brown, Paternoster-Row, 1822.

page 437



No. XVI
John Bonnycastle, Esq.,
Professor of Mathematics, at the Royal Military Academy, Woolwich

John Bonnycastle was born at Witchurch, in the county of Buckingham: his parents, although not in affluent circumstances, contrived to bestow upon their son a respectable education. At an early age the favorable opinion which his friends entertained of his acquirements, induced him to seek his fortune in London. In this great metropolis his growing taste for mathematics became strongly fixed, from an association with friends of congenial habits and pursuits. Many of these friends have since attained considerable eminence in various departments of literature.

At the early age of eighteen years, Mr. Bonnycastle married a young lady of the name of Roll, whose liberal and cultivated mind gave fair promise of many domestic hours. The hopes he cherished were, however, speedily blighted by her untimely death.

Soon after this event, the Earl of Pomfret engaged him as a private tutor to his sons (the present Earl, and the Hon. General Fermor). That he was perfectly qualified for the task every one who had the pleasure of his acquaintance will readily admit, when they recall to their memory the almost universal knowledge which he possessed, although he was nearly self-taught, not having in his early youth received the advantages of a classical education. And yet from our intimacy with him, we can assure our readers that no one, even amongst those who had received an University education, could be better acquainted with Homer, Virgil, Horace, the Grecian tragedians, and the Classics in general, than the worthy subject of this memoir. With the French, Italian, and German literature he was intimately acquainted. It is true, he could not speak those languages, but he read and knew the best of their authors. In a knowledge of the English language, no one could surpass him in appreciating the merits of our best authors in every class of composition. Like his friend Fuseli, he was a great admirer of Shakspeare, and so strongly was his immortal lines fixed upon his memory, that, on the mention of a single word in the works of that incomparable poet, he would finish the sentence and give the proper emphasis.

Mr. Bonnycastle remained about two years at Easton, in the county of Northampton; the situation he then filled, he left in consequence of being appointed one of the Mathematical masters at Woolwich, where, for more than forty years, he devoted a considerable portion of his time daily in discharging the duties of his profession; the remainder was employed in writing elementary works on the most useful branches of the Mathematics. How competent he was, has been demonstrated by the numerous editions which have been printed of those volumes. His first work was, “The Scholar’s Guide to Arithmetic,” the thirteenth edition of which is now selling. Those upon Algebra and Mensuration have long ranked as standard school-books. His “Treatise upon Astronomy” is the most popular of all works upon that sublime science; chiefly arising from the perspicuous manner in which the subject is treated, and its lucid style of composition; it has become a general library book, and will long remain as a testimony of the religious sentiments, benevolence, and great attainments of its author. Yet this very book was written by Mr. Bonnycastle, at Bath, under circumstances of peculiar depression, arising from a nervous complaint, to which he was very subject, in the early part of his life.

So far we have considered Mr. Bonnycastle as a man possessing talents of a varied, universal description, and as an author of elementary works in various branches of Mathematics; but it now remains to add a few words respecting his private character, from an intimate acquaintance with him for the last twenty years of his life. He was a good husband, a good father, and a sincere friend. In company, no man could be more attractive; he was so rich in anecdote upon all subjects, especially of literature, that his presence and conversation were productive of endless amusement as well as instruction to his auditors. His widow, three sons, and a daughter survive him; all of whom, by the most unremitting attention during his long and tedious illness, proved how much he was endeared to them by his domestic virtues.

Mr. Bonnycastle was interred at Charlton, in a vault expressly built for him. His funeral obsequies were attended by the Mathematical Masters of the Royal Academy, and several Officers of the Royal Artillery. General Ford, the Lieutenant-Governor of the Academy, bestowed a marked tribute of respect to the memory of the deceased: all the Cadets were drawn out, in two double lines, before the door, thus testifying their regard for the excellent man whose funeral procession was to pass before them.

Mr. Bonnycastle’s publications are:
1. The Scholar’s Guide to Arithmetic; 12mo. 1780.
2. Introduction to Mensuration and Practical Geometry; 12mo. 1782.
3. Introduction to Algebra; 12mo. 1782.
4. Introduction to Astronomy; 8vo. 1786.
5. Euclid’s Elements of Geometry; 8vo. 1789.
6. General History of Mathematics from the French of Bossut; 8vo. 1803.
7. A Treatise on Spherical Trigonometry; 8vo. 1806.
8. Introduction to Arithmetic, being the First Part of a General Course of Mathematics; 8vo. 1810.