xi 



laws of those operations of the mind by which reasoning is performed ; to 

 give expression to them in the symbohcal language of a Calculus, and upon 

 this foundation to establish the science of logic, and construct its method ; 

 to make that method itself the basis of a general method for the applica- 

 tion of the mathematical doctrine of Probabilities ; and, finally, to collect 

 from the various elements of truth, brought to view in the course of these 

 inquiries, some probable intimations concerning the nature and constitution 

 of the human mind.'' 



Boole has left behind him a considerable quantity of logical manu- 

 scripts ; these will perhaps be published either in a separate form or in 

 a new edition of the * Laws of Thought.' His works are his noblest mo- 

 nument, but his friends and admirers have raised other memorials. Of 

 these we may mention in particular, a memorial window in the Cathedral 

 at Lincoln, and another in the College Hall at Cork. 



The following is a list of Professor Boole's papers printed in the Philo- 

 sophical Transactions. "On a General Method in Analysis," 1844, pp. 

 225-282. "On the Comparison of Transcendents, with certain applica- 

 tions to the Theory of Definite Litegrals," 1857, pp. 745-803. "On the 

 Theory of Probabilities," 1862, pp. 225-252. "On Simultaneous Dif- 

 ferential Equations of the First Order in which the Number of the Variables 

 exceeds by more than one the Number of the Equations," 18G2, pp. 437- 

 454. "On the Differential Equations of Dynamics. A Sequel to a paper 

 on Simultaneous Differential Equations," 1863, pp. 485-501. " On the 

 Differential Equations which determine the form of the Hoots of Algebraic 

 Equations," 1864, pp. 733-755. 



Samuel Hunter Christie was born in London on the 22nd of 

 March, 1 784, and at a very early age showed the talent for mathematical 

 pursuits which afterwards so highly distinguished him. He was entered 

 at Trinity College, Cambridge, in 1801, and, in his third year, obtained 

 a scholarship. In 1805 he took his degree of Bachelor of Arts as Second 

 Wrangler, having a severe struggle with Turton (afterwards Bishop of 

 Ely) for the " Blue Riband " of the University, and being bracketed with 

 him as Smith's-prizeman. In 1806 Mr. Christie was appointed Third 

 Mathematical Master at the Royal jMilitary Academy at Woolwich, and 

 immediately devoted himself to the improvement of the mathematical 

 studies at that College, and persevered in the work with much success, 

 during his lengthened career of forty-eight years in the public service. 

 In 1812 he established the system of competitive examinations, but was 

 unable fully to carry out his views in this and in other respects until his 

 advancement to the post of Professor of Mathematics in 1838. It is not 

 too much to say that no two educational institutions could present a 

 stronger contrast than the Royal Mihtary Academy in 1806, and the same 

 College in 1854 when Mr. Christie resigned the Professor's Chair ; and this 



