Author:
Sir Frank Watson Dyson (1868-1939), Astronomer Royal who introduced Greenwich time signals ('pips') and helped prove Einstein's theory of general relativity
Publication details:
On letterhead of the Royal Greenwich Observatory. 1 July 1919.
1p., 16mo. In good condition. Reads: 'Dear Prof. Adams, | Will you give us the pleasure of your company at lunch at the Royal Observatory on July 8 at 1 o'clock?'
