Elementary astronomy; a beginner's text-book (1899)
Holden, Edward Singleton, 1846-1914 · New York, H. Holt and company · leaf 422
on the spectra of these bodies have entirely confirmed the conclusionsof Herschel. The spectroscope shows that the true nebulae aregaseous. Nebulae and clusters are divided into classes. A planetary nebulais circular or elliptic in shape, with a definite outline like a planet.Spiral nebulae are… … Fig. 207.—The Moon Passing near the Pleiades. definitions. It must be remembered that there is an almost infinitevariety of such shapes. The real shape of the nebula in space ap-pears to us much changed by perspective. Vast areas of the sky are covered with faint nebulosity. Star-clusters.—The most…
Astronomy
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
![An illustration from Novae coelestium terrestriumq[ue] rerum observationes : et fortasse hactenus non uulgatae (1646)](https://img.insideoutlibrary.com/img/200/ia-novaecoelestiumt00font-126-58.webp)
