The opinion of posterity is divided upon his merits. “By the most simple and elegant formulæ,” says Francis Baily, “he pointed out the method of solving all the most common questions relative to the value of annuities on single and joint lives, reversions, and survivorships.” The subsequent editions of his works prove that he was aware of his errors of detail, by correcting them. He enlarged the boundaries of the science which he loved, and encouraged others to follow in the same path. Although his hypothesis may not be applicable to all occasions and circumstances, and though later discoveries proved that it could not be always safely adopted, “nevertheless it is still of great use in the investigation of many cases connected with this subject, and will ever remain a proof of his superior genius and ability.” Such is the opinion of Baily on the merits of De Moivre; but it has been added by Morgan, that “on the whole the hypothesis of De Moivre has probably done more harm than good, by turning the attention of mathematicians from investigating the true laws of mortality.” In 1737, an attempt was made to calculate the number of the people, which was estimated at 6,000,000, an amount probably not very far from the mark; as in 1688 the population was reckoned at a little over 5,000,000. Some important assistance was rendered in 1738, by the publication of Kersseboom’s tables, taken from the records of life annuities in Holland[10]; and as the ages of the annuitants had been there recorded for 125 years, they proved a considerable aid to those interested. So small was the progress made in England by 1746, that Dr. Halley’s Breslau Tables and those of M. Kersseboom were the only ones which gave anything like a representation of the true laws of mortality. In this year, however, the “Essai sur les Probabilités de la Durée de la Vie Humaine” of M. De Parcieux, with several valuable tables deduced from the mortuary registers of religious houses in France, and from the nominees in the French tontines, were an additional contribution to our information.