File GPP/1/8 - Printed copies of letters from John Goodricke read before the Royal Society

Pamphlets containing printed letters written by John Goodricke and read before the Royal Society, with annotations.

Includes:
(a) Two copies of 'A Series of Observations on, and a Discovery of, the Period of the Variation of the Light of the bright Star in the Head of Medusa, called Algol'. Read at the Royal Society, May 15, 1783. Both copies include handwritten annotations, and one includes a handwritten dedication, ‘To Edwd Pigott Esq from His Friend, the Author -’.
Page 9, ‘If it were not perhaps too early to hazard even a conjecture in the cause of this variation, I should imagine it could hardly be accounted for otherwise than either by the interposition of a large body revolving round Algol, or some kind of motion of its own, whereby part of its body, covered with spots or such like matter is periodically turned towards the earth. But the intention of this paper is to communicate facts, not conjectures …’.

(b) On the Period of the Changes of Light in the Star Algol. Read at the Royal Society, April 1, 1784. ‘The method I have here pursued is by taking the intervals between accurate observations of Algol’s least brightness or greatest diminution of light made at long distances from each other, and dividing those intervals by a certain number of revolutions … The reason of my chusing long intervals is, that the number of revolutions being greater, the errors of observation are thereby diminished’.

(c) Observations of a new Variable Star. [Beta Lyrae]. Read at the Royal Society, January 1785. includes additional copies of pages 3-6.

Summary and extracts have been provided by a volunteer.