Brown/strong yellow observation of the Sun, 25 October 1905
Art
1905
Brown/strong yellow observation of sunspots made by John Willis on 25 October 1905 at 10:15am. On the reverse Willis has noted: "Approximate size of spot - 25,000 x9500 miles A- S- 0/ - penumbra 38,000 x 34,000 miles. JW". A large spot is delineated. One of 275 pencil, ink and colour wash observations of the Sun and Jupiter made by Willis in Folkestone between 1879 and 1906.