John Winthrop (1714-1779), American educator and scientist, helped liberalize the curriculum of Harvard College and received English recognition as America's leading astronomer.

John Winthrop was born in Boston, Mass., on Dec. 19, 1714, the great-great-grandson of Massachusetts Bay's first governor. He early demonstrated scholarly ability, completing Boston Latin School at 14 and graduating from Harvard in 1732. He studied science at home for six years and at 24 was named professor of mathematics and natural philosophy at Harvard.

Winthrop's public lectures and demonstrations in physical science attracted wide attention, and the results of his continuous and extensive research were published by London's Royal Society. His series of sunspot observations in 1739 were the first in Massachusetts and necessitated close cooperation with both the Royal Society and Greenwich Observatory. He noted transits of Mercury in 1740, 1743, and 1769 and also accurately recorded the longitude of Cambridge, Mass. Other studies included work on meteors (1755), the transit of Venus...