6-i Royal Society. 



revise several successive editions of Hamilton Moore's Practical 

 Navigator, which he afterwards rejjlaced by an original work on 

 the same subject, remarkable for the clearness and conciseness of 

 its rules, for its numerous and comprehensive tables, the greatest 

 part of which he had himself recalculated and reframed, and for its 

 perfectly practical character as a manual of navigation : this work, 

 which has been republished in this country, has been for many years 

 almost exclusively used in the United States of America. 



Dr. Bowditch having been early elected a Fellow of the American 

 Academy of Arts and Sciences at Boston, commenced the publica- 

 tion of a series of communications in the Memoirs of that Society, 

 which speedily established his reputation as one of tlie first astro- 

 nomers and mathematicians of America, and attracted likewise the 

 favourable notice of men of science in Europe. 



During the last twenty years of his life. Dr. Bowditch was em- 

 ployed as the acting president of an Insui'ance Company at Salem, and 

 latterly also as actuary of the Massachusetts Hospital Life Insurance 

 Company at Boston : the income which he derived fronr these 

 employments, and from the savings of former years, enabled him to 

 abandon all other and more absorbing engagements, and to devote 

 his leisure hours entirely to scientific pursuits. In 1815 he began his 

 great work, tlie translation of the Mecanique. Celeste of Laplace, the 

 fourth and last volume of which was not quite completed at tlie time of 

 his death. The American Academy over which he presided for many 

 years, at a very early j^eriod of the progress of this very extensive 

 and costly undertaking, very liberally offered to defray the expense of 

 printing it ; but he preferred to publish it from his own A'cry limited 

 means, and to dedicate it as a splendid and durable monument of his 

 OAvn labours and of the state of science in his country. He died in 

 March last, in the sixty-fifth year of his age, after a life of singular 

 usefulness and most laborious exertion, in the full enjoyment of 

 every honour which his grateful countrymen in every part of 

 America could pay to so distinguished a fellow-citizen. 



Dr. Bowditch's translation of the great work of Laplace is a pro- 

 duction of much labour and of no ordinary merit : every person who 

 is acquainted with the original must be aware of the great number 

 of steps in the demonstrations which are left nnsupplied, in many 

 cases comprehending the entire processes whicli connect the enun- 

 ciation of the propositions with the conclusions, and the constant 

 reference which is made, both tacit and expressed, to results and 

 principles, both analytical and mechanical, whicli are co-extensive 

 with the entire range of known mathematical science : but in Dr. 

 Bowditch's very elaborate commentary every deficient step is sup- 

 plied, every suppressed demonstration is introduced, every reference 

 explained and illustrated, and a work which the labours of an ordi- 

 nary life could hardly master, is rendered accessible to every I'eader 

 who is acquainted with the principles of the difterential and inte- 

 gral calculus, and in possession of even an elementary knowledge 

 of statical and dynamical principles. 



When we consider the circumstances of Dr. Bowditch's early life, 



