print: "Measuring the Sunshine"
Date: 1880
Inventory Number: 2001-1-0005a
Classification: Print
Subject:
Publisher: Illustrated London News (1842-present)
Artist: W. Bassett Murray
Cultural Region:
Place of Origin:
Dimensions:
print: 27 x 40 cm (10 5/8 x 15 3/4 in.)
in transparent folder: 31 x 46 cm (12 3/16 x 18 1/8 in.)
Description:
Illustration of a rooftop with apparatus for solar measurements at the Royal Observatory at Greenwich. In the foreground is a deck with a table, upon which is fastened wooden board. Fastened to that board, in turn, is a glass globe sitting in a bowl. Facing that table is a man with a trim beard wearing a jacket and tie and what appears to be a nightcap. He is holding a piece of paper. Next to the man is a set of stairs and a railing that reads "UP ONLY."
In the background are treetops, two cupolas, each topped with a weather vane, an observatory dome, and an unidentified building that appears to be made out of many planks, each curving slightly at the top.
In the background are treetops, two cupolas, each topped with a weather vane, an observatory dome, and an unidentified building that appears to be made out of many planks, each curving slightly at the top.
In Collection(s)
Signedtop of page: THE ILLUSTRATED LONDON NEWS, Nov. 6, 1880.--464
bottom-left corner of image: W. Bassett Murray
bottom-left corner of image: W. Bassett Murray
Inscribedbottom of page: THE ROYAL OBSERVATORY, GREENWICH: MEASURING THE SUNSHINE—SEE PAGE 459.
FunctionA look inside the Encyclopedia Britannica, Volume 26 (1911), p. 106 (available here) identifies the glass globe inside the bowl is a type of Campbell-Stokes sunshine recorder, in which the globe would focus the sunlight onto a card in the bowl. The sunlight would scorch the card. With the passage of the sun through the sky, the focused light would scorch a line in the card. The areas that were scorched represented the times of day when the sun was shining with sufficient brightness for the card to be burned.