RT @HistAstro: The remaining 10ft of the speculum end of Wm. Herschel’s 40ft telescope tube @ROGAstronomers collections.rmg.co.uk/collections/ob… https://t.co/OUJXVQ7XRA
RT @HistAstro: The remaining 10ft of the speculum end of Wm. Herschel’s 40ft telescope tube @ROGAstronomers collections.rmg.co.uk/collections/ob… https://t.co/OUJXVQ7XRA