Eliot was born at Lamesley in Durham, son of Peter Elliott of Lamesley, schoolmaster, by his wife Margaret. He changed the spelling of his surname to Eliot. Matriculating at the rather late age of twenty-six at St. John's College, Cambridge, in 1865, he graduated B.A. in 1869 as second wrangler and first Smith's prizeman. Soon elected to a fellowship, he accepted, owing to weak health and with a view to avoiding the climate of England, the professorship of mathematics at the Engineering College at Roorkee in the North-West Provinces, under the Indian government. In 1872 he was transferred to the regular Indian Educational Service as professor of mathematics at the Muir Central College, Allahabad. With that office was combined that of superintendent of the Meteorological Observatory. In 1874 he migrated to Calcutta as professor of physical science in the Presidency College and meteorological reporter to the government of Bengal. In 1886, he succeeded Henry Francis Blanford as meteorological reporter to the government of India and was appointed in addition director-general of Indian observatories in 1899. Blanford had established a link between snowfall in the Himalayas and the intensity of the monsoons. Famine years were preceded by heavy snowfall in the Himalayas. Eliot took this further by examining correlations between the monsoons and weather in other parts of the world. Eliot however did not use numerical approaches to examine these relations and believed for instance that a high pressure over Mauritius contributed to the intensity of the monsoons. Based on such ideas he began to produce monsoon forecasts that ran to nearly 30 pages. In 1899, his prediction of higher than normal rains led to considerable embarrassment for the government as India suffered a famine. Reviews in the newspapers led to subsequent predictions being issued as confidential reports to the government. Eliot however improved the organisation of meteorological work in India that had been begun by Blanford. "The number of observatories working under or in connection with the department was increased from 135 to 240 (including two at an elevation of over 11,000 ft.) and the co-operation of the larger native states was secured. Under Sir John Eliot's superintendence the diffusion of weather information was extended by the issue of frequent reports at various centres. Methods of giving warnings of storms at sea were developed and telegraphic intimations of impending floods to engineers on large works under construction or in charge of railway canals and bridges saved the state from heavy losses. Vast improvement was effected in the mode of announcing . . . prospective drought and consequent danger of famine over greater or lesser areas."
