...He was enjoying his meal when he happened to lookup, and saw that the penumbra at the edge of the lighted zone was densewith beetles... 
Victor Rousseau 「Astounding Stories of Super-Science January 1930」
...It is bordered onboth sides by the spectrum of the penumbra, which is much brighterthan that of the umbra, but fainter than that of the adjoining regionsof the sun...
Robert Stawell Ball 「The Story of the Heavens」
...A spot is usually composedof a dark central portion called the umbra, and a less dark fringearound this called the penumbra (, p...
Cecil G. Dolmage 「Astronomy of To-day」
... The time occupied by the Moon in passing throughthe penumbra, before and after a lunar eclipse, will generallyrun to about an hour for each passage...
George Chambers 「The Story of Eclipses」
...Wherever the penumbra falls there will be a solareclipse of some kind, and the nearer the place is to the axisof the penumbra, the more nearly total will be the eclipse...
George C. Comstock 「A Text-Book of Astronomy」
...When asun-spot has completed its period of existence, the photospheric matteroverwhelms the penumbra, and rushes into the umbra, which itobliterates, causing the spot to disappear...
Thomas Orchard 「The Astronomy of Milton's 'Paradise Lost'」
...The penumbra of a spot was formed by the thinner parts of theatmosphere about the vacancy which surrounded the nucleus...
Edward Singleton Holden 「Sir William Herschel: His Life and Works」
...): the penumbra continued uponher disc for an hour afterwards...
George Chambers 「The Story of Eclipses」
...Grover has not only seen theabove-named features, but even a penumbra to the shadow on the ringswith a 2-inch telescope...
Richard A. Proctor 「Half-hours with the Telescope」
...The penumbra attending the earth's shadow is usually supposed to render this observation uncertain to two or three minutes of time, or more than half a degree of longitude...
Matthew Flinders 「A Voyage to Terra Australis」
便利！手書き漢字入力検索
この漢字は何でしょう？？