791] 
583 
791. 
LANDEN. 
[From the Encyclopcedia Britannica, Ninth Edition, vol. xiv. (1882), p. 271.] 
Landen, John, a distinguished mathematician of the 18th century, was born at 
Peakirk near Peterborough in Northamptonshire in 1719, and died 15th January 1790 
at Milton in the same county. Most of his time was spent in the pursuits of active life, 
but he early showed a strong talent for mathematical study, which he eagerly cultivated 
in his leisure hours. In 1762 he was appointed agent to the Earl Fitzwilliam, and 
held that office to within two years of his death. He lived a very retired life, and 
saw little or nothing of society ; when he did mingle in it, his dogmatism and 
pugnacity caused him to be generally shunned. He was first known as a mathematician 
by his essays in the Ladies Diary for 1744. In 1766 he was elected a Fellow of the 
Royal Society. He was well acquainted and au courant with the works of the mathe 
maticians of his own time, and has been called the English D’Alembert. In his 
Discourse on the “ Residual Analysis,” in which he proposes to substitute for the method 
of fluxions a purely algebraical method, he says, “ It is by means of the following 
theorem, viz. 
m 
m 
(where m and n are integers), that we are able to perform all the principal operations 
in our said analysis ; and I am not a little surprised that a theorem so obvious, and 
of such vast use, should so long escape the notice of algebraists.” The idea is of 
course a perfectly legitimate one, and may be compared with that of Lagrange’s Calcul 
des Fonctions. His memoir (1775) on the rotatory motion of a body contains (as the 
author was aware) conclusions at variance with those arrived at by D’Alembert and