By the end of the nineteenth century the Sunday school had become a global institution. The Second International Sunday School Convention, held in St Louis, Missouri, in 1893, estimated the total number of pupils enrolled in Sunday schools worldwide at over twenty million. Of these, some 208,000 were in India and Ceylon, few of whom were Christian children. What may surprise the British reader is that the majority of Indian Sunday schools were associated with American rather than British Protestant missions. More broadly, Belvadi makes the interesting point that American missionaries, excluded from British India until the revision of the East India Company Charter in 1833, outnumbered British ones by the close of the century. Moreover, on the evidence he presents, their enthusiasm for British rule matched that of their British colleagues – missionary enthusiasm for colonial rule often had little to do with national affiliation.

The rapid expansion of mission-run Sunday schools in India followed in the wake of Sir Charles Wood's Education Dispatch of 1854, which effectively closed the door on the provision of Bible teaching in day schools receiving government grants-in-aid. In response, missions turned to the Sunday school as an independently-financed mechanism of reaching the young with Christian teaching. Missionaries were not above paying Hindu day-school teachers to send their pupils to Sunday school, and the impoverished teachers were glad of the money. Popular demand for education was such that Hindu or even Muslim parents were often willing to send their children to Sunday school. Hindus also began their own Sunday schools in imitation of Christian models.

Missionary calculus is not a history of the Indian Sunday school as such. Belvadi says little about the schools operated by British missions. Conversely, a fair proportion of his book is devoted to a broader discussion of educational policy in British India. Chapter i draws on Max Weber to offer an elaborate theoretical foundation for the study in terms of the ‘instrumental rationality’ of the missionaries. What this boils down to is the unremarkable observation that they would do whatever it took to achieve the growth of the institutions they had founded, even at the cost of watering down their evangelistic character. Chapter ii surveys the history of day-school education in British India under Company rule, and points out that the famous monitorial method of elementary teaching disseminated by the East India Company chaplain Andrew Bell was in fact borrowed from Indian precedent in Malabar. Chapter iii sets biographical studies of the two pioneers of the American Sunday school movement in India – the Methodist missionary Thomas Jefferson Scott and the Free Will Baptist James Liddell Phillips – in the context of the affluent lifestyle of missionaries in British India as ‘pādri sāhibs’. Chapter iv charts the growth of Sunday schools in India, presenting the statistics of missionary investment and numerical returns alluded to in the ‘calculus’ of the book's title. Chapter v traces the indebtedness of the movement to modern educational theory, notably the philosophy of early childhood learning as propounded by Froebel and Pestalozzi; it pays particular attention to Scott's widely-used Indian Sunday-school manual (1882). Chapter vi widens the lens well beyond American mission Sunday schools by discussing in classic postcolonial vein a range of examples of Christian mimicry of Hindu religious symbols and ceremonies. It is Belvadi's most interesting, though also most speculative, chapter. An analysis of the Anglican (Society for the Propagation of the Gospel) mission at Sawyerpuram in Tamil Nadu suggests that the local Christians fashioned their welcome ceremony for the bishop on his travels on Hindu devotional precedent; he and his wife were carried into the town on a ceremonial palanquin, just like a Hindu deity and his consort. Belvadi uses the elaborate nature of the tamáshá (spectacle) laid on for the bishop at Sawyerpuram, as also at another British mission – the annual Sunday school fete at the Church Missionary Society mission at Lucknow in North India – to offer some stimulating observations on the ‘casteization of Christianity’. Both missionaries and Indian Christians observed rituals and separate dining practices that made a caste of themselves. This chapter also includes an analysis of the Tamil hymnbook, Christian lyrics for public and school worship, compiled in 1875 by the American Board missionary Edward Webb for both congregational worship and Sunday school use. Many of the hymns that Webb included were written by the remarkable Tanjore Christian poet, Vēdanāyagam Sāstriar (1774–1864); Sāstriar's hymns conformed to classical Hindu musical forms, employing Sanskritic literary style to convey Christian truth.

This is in places an illuminating study, but the author is not entirely sure-footed in negotiating what is clearly for him uncongenial terrain: we are informed, for instance, that for American missionaries, ‘the philanthropic impulse of educating the needy was aligned with the power of the jackboot’ (p. 63). Readers may struggle to follow the logic behind the successive shifts in focus from day-school education to American mission Sunday schools, and then to Anglican or Lutheran missions. Belvadi's engagement with standard scholarship on Christianity in India is decidedly patchy. He seems unaware of H. J. A. Bellenoit's Missionary education and empire in late colonial India, 1860–1920 (Oxford 2007), Penelope Carson's authoritative work on The East India Company and religion, 1698–1858 (Cambridge 2012) and Indira Viswanathan Peterson's detailed exposition of Sāstriar's hymns in Judith M. Brown and Robert Eric Frykenberg's Christians, cultural interactions, and India's religious traditions (Cambridge 2002). C. F. Schwartz of the Tranquebar mission appears as ‘Swartz’. Joshua Marshman of Serampore was not a weaver (p. 40) – though his father was – but a schoolmaster. Moreover, the author's habit of referring repeatedly to his missionaries as ‘Rev. Scott’, ‘Rev. Phillips’, and so on, is stylistically incorrect and grates on the reader's ear.