Elementary astronomy; a beginner's text-book (1899)
Holden, Edward Singleton, 1846-1914 · New York, H. Holt and company · leaf 135
nd poured froma box through a hole in the bottom. The lowering of theupper surface of the water or sand marked the passage oftime. The common hour-glass is a sand-clock. Candleswere marked by lines at equal intervals and equal intervalsof time were counted by the burning of equal lengths ofwax. The… … ASTRONOMICAL INSTRUMENTS. 115
Astronomy
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