Tontine
2 of the 7 encyclopedias on this shelf carry an entry for Tontine. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
ton-ten', a form of investment. It is named for its suggestor, Lorenzo Tonti, a citizen of Naples who settled in Paris in the time of Mazarin. In its simplest form a tontine is a joint investment the profits of which are to be paid to the surviving investors. Payments cease when the last investor dies. In 1689, for instance, Louis XIV of France, then in need of money, organized a tontine of $70,000,000. It was divided into fourteen different classes, practically fourteen different tontines. Shares were placed at three hundred livres, $57.90 each. The French government pledged itself to divide a fixed sum annually among the surviving shareholders. This tontine existed forty years. The last shareholder, a widow, all others being dead, received an annual income of $14,185.50. At her death the obligation to pay dividends ceased. Numerous private tontines have been organized on a large scale. The tontine La Farge of Paris drew 60,000,000 francs from subscribers and then failed. A government tontine opened in England in 1789, ran for seventy years, and paid the surviving subscriber $210,150 a year. The tontine plan for erecting public buildings was formerly popular in the United States . A fixed rental was paid the surviving subscribers. Even though the return was small in comparison with the total amount subscribed, the subscribers who lived the longest derived a fine income. At the death of the last survivor the building reverted to the public, free of incumbrance. Some life insurance companies have adopted a tontine policy whereby the persistent payers of premiums reap a benefit from those who drop out. See Insurance
Collier's New Encyclopedia (1921)
a term derived from the name of Lorenzo Tonti, a Neapolitan, who settled in Paris in Cardinal Mazarin's time, and proposed in 1653 to raise a fund of $125,000,000 for the relief of the national exchequer by means of a ex financial association, of which the great prize should ultimately accrue to the longest liver. There were to be shares of $1,500. The subscribers were to be divided into 10 classes according to age; and for each class a fixed sum was annually to be divided equally among the members of the class. In this way, while each member should get fair interest from the first on his capital, the profit falling to survivors would increase as years went on, and the last survivor would receive the whole of the interest he-belonged to. The hedue to the class tontine is a lottery of annuities-or.compounded of lottery and annuity-and was frequently had recourse to in France in the 18th century, with government sanction.