JOHN FLAMSTEED (1646 – 1719)
The father of modern astronomy, who corrected all the astronomical tables in use in the 17th century, who made Newton’s discoveries possible, became an astronomer by chance. Unable to attend school because of rheumatism – which he suffered throughout his life – he began to teach himself. One of the books that came his way was Sacroboseo’s ‘De Sphaera’. It was the turning point.
In September 1662 he observed a partial solar eclipse and he made himself a rough quadrant. He compiled a table of the sun’s altitudes. It was not long before his talents attracted notice. This led to his meeting with Sir Jonas Moore in London. For a start he presented the boy with Townley’s micrometer and glasses for a telescope to be fitted. From London he journeyed to Cambridge where he made acquaintance of Isaac Newton. Next year, in 1671, Flamsteed began his systematic observations, which resulted in his discovery that the varying dimensions of the moon completely contradicted all the theories of Lunar Motion, except those of Horrocks. Flamsteed’s observatory validated Horrocks’ theory which he prepared with additional explenations for publication.
In 1673 he wrote a tract on the real and apparent diameters of the planets which gave Newton the data for the subject of his third book ‘Principia’.
Meanwhile a Royal Observatory at Greenwich was founded and he was made in charge. As the first ‘Astronomer Royal’ he achieved magnificent results despite of various difficulties. He took to himself to correct the existing astronomical theories and tables. His first observation for this purpose was made in September 1676 and by 1689 he had made 20,000.
To remedy the lack of instruments to determine the equinox, he constructed a mural arc a novel method which yielded interesting results.
Professional jealousies was to come in between Flamsteed and Newton. In 1681 his observations on the great comet were transmitted to Newton which he used in the ‘Principia’. Flamsteed maintained that the comet was the one which had appeared earlier in the year before, but Newton held that there were two comets, which he corrected after four years. The breach between them widened still further over the publications over his sextant observations during 1676 – 1689.
The committee of the Royal Society, of which Newton was the president, brought out Flamsteed’s observations incomplete and inaccurate.
Edmund Halley, who succeeded Flamsteed, was the editor of that controversial publication. Therefore Flamsteed set himself to publish independently a complete and proper account of his work, which however, was published posthumously in 1725.
The irritable old man had contributed to the sighting of 2935 stars, the proudest moment for the Royal Observatory at Greenwich.