Benjamin Gompertz
Born: 5 March 1779 in London, England
Died: 14 July 1865 in London, England
Benjamin Gompertz came from a family of merchants who left Holland and settled in England. He was one of three sons born in England to the Dutch family which, although from Holland, was Jewish. Gompertz was self educated, learning mathematics by reading Newton and Maclaurin. He had to take this route since he was denied admission to universities since he was Jewish. In fact he was greatly helped in his mathematical education by the Society of Mathematicians of Spitalfields which was later to become the London Mathematical Society. Gompertz, writing to De Morgan, explained how he came to be a member of the Society [5]:-
As to the Mathematical Society, of which I was a member when only 18 years of age, having been, contrary to the rules, elected under the age of 21. How I came to be a member of that Society - and continued so until it joined the Astronomical Society, and then was the President - was: I happened to pass a bookseller's small shop of second hand books, kept by a poor taylor, but a good mathematician, John Griffiths. I was very pleased to meet a mathematician, and I asked him if he would give me some lessons; and his reply was that I was more capable to teach him, but he belonged to a society of mathematicians, and he would introduce me. I accepted the offer, and I was elected, and had many scholars then to teach, as one of the rules was, if a member asked for information, and applied to one who could give it, he was obliged to give it, or fine one penny.
In 1810 Gompertz married Abigail Montefiore who came from a wealthy Jewish family with strong links with the stock exchange. Gompertz himself joined the stock exchange in 1810 and he became a Fellow of the Royal Society in 1819. The following year he read a paper to the Society which applied the differential calculus to the calculation of life expectancy. In 1824 he was appointed as actuary and head clerk of the Alliance Assurance Company.
Gompertz applied the calculus to actuarial questions and he is best remembered for Gompertz's Law of Mortality. Gompertz, in 1825, showed that the mortality rate increases in a geometric progression. Hence, when death rates are plotted on a logarithmic scale, a straight line known as the Gompertz function is obtained. It is the most informative actuarial function for investigating the ageing process. The slope of the Gompertz function line indicates the rate of actuarial ageing. The differences in longevity between species are the result primarily of differences in the rate of ageing and are therefore expressed in differences in slope of the Gompertz function.
Tropp writes in [1]:-
[Gompertz's] rigid adherence to Newton's fluxional notation prevented wide recognition of his accomplishment, but he must be rated as a pioneer in actuarial science and one of the great amateur scholars of his day.
Gompertz also wrote about scientific instruments, writing Theory of astronomical instruments (1822), A new instrument called the differential sextant (1825) and On the converted pendulum (1829).