Wheler, or ‘Wheler Chapel,’ in Spital Square, which had been shut up for some time. For sixteen years he enjoyed this humble preferment. He established in connection with it the ‘Spitalfields Benevolent Society,’ and among his congregants were Samuel Hoare of Hampstead, the friend of the Wordsworths, and Thomas (afterwards Sir Thomas) Fowell Buxton [q. v.] The latter, with several friends, left, at Pratt's suggestion, the Society of Friends, and were baptised into the church of England.
Pratt's interest in church affairs abroad was always keen. He worked actively in promoting an ‘ecclesiastical establishment’ in India, stimulating Dr. Claudius Buchanan to renew his efforts, and urging the Church Missionary Society to give practical aid when Dr. Thomas Fanshaw Middleton [q. v.] was appointed bishop of Calcutta. In 1820 Pratt corresponded with two American bishops (Drs. Griswold and White), and warmly welcomed Dr. Philander Chase, bishop of Ohio, on his visit to England; and it was greatly through his efforts that an American missionary society was established. He similarly took the warmest interest in the mission of his brother-in-law, William Jowett [q. v.], to Malta and the Levant, and may be regarded as founder, in conjunction with Dr. Buchanan, of the Malta mission.
In 1826, when Pratt was fifty-eight, he at length became a beneficed clergyman. The parishioners of St. Stephen's, Coleman Street, who had the privilege of electing their own vicar, had chosen him their vicar as early as 1823. But legal difficulties arose, and were not overcome for three years. He retained his lectureship at St. Mary Woolnoth until 1831. He established various Christian and benevolent institutions in St. Stephen's parish, did what he could to stem the progress of the Oxford movement, and took part in the formation of the Church Pastoral Aid Society. To the last Pratt remained a prominent leader of the evangelicals. Alexander Knox described a meeting with him at Mrs. Hannah More's, and called him ‘a serious, well-bred, well-informed gentleman, an intimate friend of Mrs. More's and Mr. Wilberforce's.’ By the word ‘serious’ Knox disclaims meaning ‘disconsolate or gloomy’ (Remains, iv. 68). Pratt died in London on 10 Oct. 1844, and was buried in ‘the vicars' vault’ in the church of St. Stephen's, Coleman Street. By his wife Elizabeth, eldest daughter of John Jowett of Newington, he was father of Josiah, his successor at St. Stephen's; and of John Henry (see below).
In spite of his many and varied occupations, Pratt found time for literary work. In 1797 he issued ‘A Prospectus, with Specimens, of a new Polyglot Bible for the use of English Students,’ a scheme for popularising the labours of Brian Walton. The ‘British Critic’ attacked him for presuming to trespass on that scholar's province. Pratt published a ‘Vindication;’ but the scheme fell through. He edited the works of Bishop Hall (10 vols. 1808), of Bishop Hopkins (4 vols. 1809), ‘Cecil's Remains’ (1810), and Cecil's ‘Works’ (4 vols. 1811). Among his other works were ‘Propaganda, being an Abstract of the Designs and Proceedings of the Society for the Propagation of the Gospel in Foreign Parts, with Extracts from the Annual Sermons. By a Member of the Society,’ 1818; ‘A Collection of Psalms and Hymns,’ 750 in number, for the use of his parishioners in public worship, of which no less than fifty-two thousand copies were sold; and another ‘Collection’ for private and social use.
Pratt's second son, John Henry Pratt (d. 1871), graduated B.A. from Caius College, Cambridge, as third wrangler in 1833; was elected to a fellowship and proceeded M.A. in 1836; and was appointed a chaplain of the East India Company, through the influence of Bishop Wilson, in 1838. He became Wilson's domestic chaplain, and was in 1850 appointed archdeacon of Calcutta. He died at Ghazeepore on 28 Dec. 1871. At the instance of Bishop Milman, by whom he was held in high esteem, a memorial to him was erected in Calcutta Cathedral. Pratt was the author of ‘Mathematical Principles of Mechanical Philosophy’ (1836, 8vo), subsequently expanded and renamed ‘On Attractions, Laplace's Functions and the Figure of the Earth’ (1860, 1861, and 1865). He also published a small work entitled ‘Scripture and Science not at Variance’ (1856), which went through numerous editions; and, in 1865, edited from his father's manuscript ‘Eclectic Notes, or Notes of Discussion on Religious Topics at the Meetings of the Eclectic Society, London, during the years 1798–1814; (see Times, 2 and 29 Jan. 1872; Allibone, Dictionary; Todhunter, Analytical Statics, pref.)
[Memoir by Pratt's sons, Josiah and John Henry, 1849; Funeral Sermons on the Rev. Josiah Pratt by the Revs. E. Bickersteth, H. Harding, and H. Venn; Christian Observer for 1844 and 1845; Farewell Charge of the Bishop of Calcutta (Daniel Wilson), 1845; Remains of Alexander Knox, vol. iv.; Overton's English Church in the Nineteenth Century, 1800–1833.]