114 GREAT MEN OF SCIENCE 



as a model for the further development of calculating 

 machines up to the present day. 



In the next year, 1673, Leibniz went for the first time to 

 London. There the secretary of the Royal Society (Olden- 

 burg, born in Bremen), quickly introduced him into the circle 

 of the Society, to which he also showed his calculating 

 machine brought from Paris. Boyle, one of the oldest mem- 

 bers, gave Leibniz special opportunities to exchange ideas with 

 the mathematicians of the Society, whereby his extraordinary 

 gifts, in spite of his own very modest statements (also in 

 writing to Oldenburg) concerning his then deficient mathe- 

 matical schooling, appeared to have been correctly estimated; 

 for he was immediately made a member of the Society. A 

 year before, Newton had been made a member. 



After two months stay in London, Leibniz went back to 

 Paris, where he remained three years. There he carried out 

 extensive mathematical studies, having in this the help of 

 Huygens, whose Horologium Oscillatorium formed the subject 

 of his special study. He also corresponded with the London 

 Royal Society, exchanging ideas on mathematical subjects. 

 Leibniz thus moved in the circles which represented, in the 

 person of the most eminent members, all ideas of that time 

 concerning the necessity for calculation with infinitely small 

 quantities which had arisen in the progress of science since 

 Galileo's time; indeed, ideas concerning actual methods for 

 this purpose, for Newton had already been for ten years in 

 possession of one in his method of fluxions. It is certainly 

 characteristic of Leibniz's quite extraordinary capacity for 

 grasping the essential, and for immediately advancing to new 

 results in all subjects that he took up, however little he may 

 previously have concerned himself with them, when we see 

 from the correspondence of that time that at the end of his 

 stay in Paris, in the year 1676, he was already in possession 

 of the new calculus in a fully developed state, calling it the 

 'differential calculus,' without anything having been published 



