Paper, on telescopes and how to use them by [Robert Hooke?]

Description

A paper, possibly by Robert Hooke, regarding telescopes and how to use them. A portion of this text, describing figure 4, was printed along with three of the illustrations in Philosophical Transactions in a paper by Hooke. Includes five illustrations.

Subject: Astronomy / Scientific Instruments

Some figures and portions of text published in Philosophical Transactions as 'A description of an instrument for dividing a foot into many thousand parts, and thereby measuring the diameters of planets to great exactness, &c. as it was promised, Numb. 25.'

Adrian Auzout's report of some astronomical observations, using an instrument which could divide a foot into 24,000 or 30,000, in 'Philosophical Transactions' vol. 1, no. 21 (January 1667) triggered a letter from Richard Towneley in Lancashire claiming priority for William Gascoigne (c. 1620-1644). Gascoigne had applied a micrometer in the optical path of a telescope for measuring small angles by 1639. His micrometers came into the hands of Richard Towneley (whose uncle Christopher Towneley had been Gascoigne’s patron), who claimed to have improved on the instrument, though the details of the improvement are unclear. Robert Hooke substituted the solid sights with hair sights. Towneley’s letter was printed in 'Transactions', vol. 1, no. 21 (May 1667) and the figures of the instrument, drawn by Robert Hooke, in 'Transactions', vol. 2, no. 29 (November 1667).

Reference number

CLP/2/13

Earliest possible date

1667?

Physical description

Ink on paper

Page extent

5 pages

Format

Manuscript