diurnal motion

American  

noun

Astronomy.

1. the apparent daily motion, caused by the earth's rotation, of celestial bodies across the sky.

---

diurnal motion British  

noun

1. motion that occurs during the day or daily, such as the diurnal rotation of the celestial sphere

---

Example Sentences

Cassini, moreover, set up an altazimuth in 1678, and employed from about 1682 a “parallactic machine,” provided with clockwork to enable it to follow the diurnal motion.

From Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 7 "Arundel, Thomas" to "Athens" by Various

The diurnal motion is compensated by motion about the polar axis only, the other being clamped.

From Pioneers of Science by Lodge, Oliver, Sir

II.—The stars and their diurnal motion 10 Finding the stars—Their apparent motion—Latitude—Direction of the meridian—Sidereal time—Definitions.

From A Text-Book of Astronomy by Comstock, George C.

The title of this paper was Astronomical Observations on the Rotation of the Planets round their Axes, made with a view to determine whether the Earth's diurnal motion is perfectly equable.

From Sir William Herschel: His Life and Works by Holden, Edward Singleton

The effect of the diurnal motion is conspicuous to every one, and explains the rising, southing, and setting of the whole visible firmament.

From Pioneers of Science by Lodge, Oliver, Sir