John Flamsteed

Astronomical instruments used by Flamsteed at Greenwich, as depicted in: John Flamsteed. Historiae coelestis Britannicae. Londini: typis H. Meere, 1725 [Rare Books Collection FOL. QB7 FLA]John Flamsteed (1646-1719) was appointed Astronomer Royal in 1675 but by the turn of the eighteenth century had not yet published any of his observations. Isaac Newton and Edmond Halley pressed him to do so, taking the view that, as he was a state official, his data should be published for the public good.

Furthermore, Newton needed accurate observations to enable him to revise his lunar theory and Flamsteed was the only one who could supply him with them. Flamsteed wished to publish his data but wished to refine it first and, given that he used his own money to buy and maintain his astronomical instruments and employ calculators, was of the opinion that he was entitled to take his time.

In 1704 Flamsteed drew up a document laying out the contents of his proposed Historiae coelestis. He circulated it to a number of friends and, although it was not his intention, it was read out at a meeting of the Royal Society. A deputation of the Society, headed by Newton, then made an approach to Prince George of Denmark, the Queen’s consort, who agreed to finance publication. George then appointed a committee, led by Newton, first to assess the cost of printing the work and then to supervise expenditure on it.

Flamsteed was persuaded to hand his manuscript observation records and a sealed copy of his incomplete star catalogue to the referees and to promise to supply the data for a full catalogue later. Printing of Flamsteed’s observations then proceeded but very slowly, and when Prince George died, Flamsteed, believing that the referees’ authority had ceased, stopped cooperating with the committee. Halley was then entrusted with the task of publishing the rest of the observations and the incomplete star catalogue. He made numerous changes, altering the descriptions of stars and adding ones not in the original. This much altered and incomplete version was published in 1712, much to Flamsteed’s annoyance.

However in 1715, following the accession of George I, and after making an application to the lords of the Treasury, Flamsteed succeeded in obtaining 300 unsold copies of the 1712 Historia coelestis. He then made ‘a Sacrifice of them to heavenly Truth’ by making a bonfire of them at Greenwich. Flamsteed continued to prepare his own version for the press but died before it could be completed. His wife and his two former assistants, Joseph Crosthwait and Abraham Sharp, prepared it for publication. It finally appeared in 1725, much as Flamsteed had wanted it to, except for the omission of the details of his quarrels with Newton and Halley, which he had wanted to include.

Shown here is Flamsteed’s mural arc, a wall-mounted instrument for measuring the altitudes of stars as they pass the meridian.

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