164< DE MOIVRE. 



After I had solved the foregoing Problem, which is about 12 years 

 ago, I spoke of my Solution to Mr. Henry Stuart Stevens^ but with- 

 out communicating to him the manner of it: As he is a Gentleman 

 who, besides other uncommon Qualifications, has a particular Sagacity 

 in reducing intricate Questions to simple ones, he brought me, a few 

 days after, his Investigation of the Conclusion set down in my third 

 Corollary; and as I have had occasion to cite him before, in another 

 Work, so I here renew with pleasure the Expression of the Esteem 

 which I have for his extraordinary Talents : 



Then follows the investigation due to Stevens. The above 

 passage occurs for the first time in the second edition, page 140 ; 

 the name however is there spelt Stephens : see also Art. 270. 



Problem XLVII. is not in the first edition ; on the other hand, 

 a table of numerical values of chances at Hazard, without ac- 

 companying explanations, is given on pages V7% 175 of the first 

 edition, which is not reproduced in the other editions. 



297. Problems XLVIII. and XLix. relate to the game of Raffling. 

 If three dice are thrown, some throws will present triplets, some 

 doublets, and some neither triplets nor doublets; in the game 

 of Raffles only those throws count which present triplets or 

 doublets. The game was discussed by Montmort in his 

 pages 207 — 212 ; but he is not so elaborate as De Moivre. Both 

 writers give a numerical table of chances, which De Moivre says was 

 drawn up by Francis Eobartes, twenty years before the publica- 

 tion of Montmort's work ; see Miscellanea Analytica, page 224. 



Problem XLIX. was not in De Moivre's first edition, and 

 Problem XLVIII. was not so fully treated as in the other edi- 

 tions. 



298. Problem L. is entitled Of Whisk; it occupies pages 172 — 179. 

 This is the game now called Whist. De Moivre determines the 

 chances of various distributions of the Honouy^s in the game. Thus, 

 for example, he says that the ^probability that there are no Honours 



on either ride is ^c ' ^^^ of course means that the Honours 



are equally divided. The result would be obtained by considering 

 two cases, namely, 1st, that in which the card turned up is an 



