Four images of the solar surface, 1915 August

Printed label glued on back: "MOUNT WILSON SOLAR OBSERVATORY / B 25 Sun-spot Group, August 3, 5, 7 and 9, 1915, H[alpha] Hydrogen". n/a. Extent: 1 photograph. Size and dimensions of original material: Height 19cm, width 21cm. Condition of original material: Slight damage (dirty, fish moth damage). Author(s)/Creator(s): English. Scribe(s): Latin. Publisher(s): Left-to-Right. Editor(s): Unrestricted. Volume number: N/a. Original institution reference: PB12_P0514.