instead Bishop Cotton. They held each other in high esteem. In 1864 an order was passed by the Secretary of State in India to retire chaplains after twenty-five years (earlier unlimited). An exception was made for Pratt and he was extended from October 1867 to March 1869 based on pleas from Bishop Cotton. When Pratt wished to resign in 1869, the Secretary of State extended his service to October 1872. After the death of Bishop Cotton in 1866, Pratt started a Hill Schools' Nomination Endowment Fund to help support Bishop Cotton's scheme of starting schools in the pleasant climate of the hills for the benefit of the children of poorer English residents in India who could not afford an education in England. Pratt married Hannah Maria Brown, daughter of George Francis Brown, a Bengal Civil Servant, at Bhagalpur on 6 March 1854. He was elected Fellow of the Royal Society in 1866. Pratt served as president of the Calcutta Society for Prevention of Cruelty to Animals founded by Colesworthey Grant in 1861. He died from cholera when he was on a visit to Ghazipur, India, on 28 December 1871. At the instigation of Bishop Robert Milman, a memorial to Pratt was erected in St. Paul's Cathedral, Calcutta. Works Pratt was the author of Mathematical Principles of Mechanical Philosophy (1836), subsequently expanded and renamed On Attractions, Laplace's Functions and the Figure of the Earth (1860, 1861, and 1865). The final edition is a treatise of some 162 pages. The fundamental goal of the text is to supply an answer to the question as to whether the earth acquired its present form from originally being in a fluid state. The book is organised in two parts, the first takes Newton's law of universal gravitation as starting point, calculates the resulting force exerted at a point by a total mass in forms ranging from sphere to spheroid and subsequently to an irregular mass consisting of nearly spherical layers approximating more and more to the case of the earth. The second part is concerned with calculating the shape of the earth based first on the hypothesis of it being a fluid and then on geodetic principles. Part of his work was extensively used verbatim by Isaac Todhunter in his Treatise on Analytical Statics (1853). Even as he travelled to India in 1838 aboard the Duke of Buccleuch he conducted experiments to examine currents in