Obituaries. 
205 
1920-21.] 
Dr Sprague was elected Associate of the Institute of Actuaries in 1856. 
His first paper is to be found in the Institute Journal, vol. vi, on a certain 
method of distributing surplus. He was elected a Fellow of the Institute 
in 1857, and was elected to the Council in 1863. He remained a member 
until his retirement from business in 1900, a period of thirty-eight years, 
which is a record. He edited the Journal of the Institute from 1867 to 
1883, and the volumes published during his editorship bear witness to 
his skill and zeal. Elected President of the Institute in 1882, he occupied 
the Presidential Chair for four years. During his Presidency the Institute 
received its Charter. In 1874 he was elected a Fellow of the Faculty 
of Actuaries in Scotland, and was President from 1894-1896. No one 
else has occupied the Presidential Chairs of both the Institute and the 
Faculty. He was also President of the Actuarial Society of Edinburgh on 
three occasions, 1874, 1882, and 1891. 
Besides being an Actuary of unusual erudition, Dr Sprague was a first- 
class business man. The business of life assurance, using the words “ life 
assurance ” in their broadest sense, was the business of his life, and in all 
his investigations he kept in view their immediate practical application, and 
refrained from acting on any theories he might have formed until he had 
put them to practical test. His writings all bear witness to this ; and one 
would like to refer to them in some detail, but in this short notice it is 
impossible. The communications to the Journal of the Institute alone 
occupy nearly five and a half pages of the index. Of other actuarial 
publications special mention may be made of his volume on Life Insurance 
Accounts (1874); his contributions to the 9th Edition of the Encyclopaedia 
Britannica, particularly an exhaustive article on “Annuities,” in some parts 
highly mathematical, which superseded the article by Joshua Milne written 
many years before ; and sundry contributions to the Transactions of the 
Actuarial Society of Edinburgh. The construction and use of his monu- 
mental Select Tables were fully explained in two elaborate papers to the 
Journal of the Institute of Actuaries, vol. xxi, p. 229, 1878, and vol. xxii, 
p. 391, 1881, and in 1896 they were published separately in book form, 
with extensive monetary tables at four rates of interest. He also took a 
great part in the preparation of what are now known as the Institute of 
Actuaries’ Life Tables. 
Dr Sprague’s energies were not confined to matters actuarial. He 
published various mathematical papers in the Transactions and Proceedings 
of the Royal Society of Edinburgh and of the Edinburgh Mathematical 
Society ; and was besides an active member of the Edinburgh Field 
Naturalists and Microscopical Society, to the publications of which he 
