spectroscopic analysis of the light from the stars, which are suns many of them much greater than our own, shows that they are of various ages-some quite young, some arrived at maturity, and some passing into old age.
"The Law and the Word"
Thomas Troward
They have the same structure and the same chemical composition; they have the same physical properties, the glow, the fire, and the brilliancy of our spectroscopic gratings.
"The Mechanism of Life"
Stéphane Leduc
They may be there, probably are there, but the spectroscopic proof of their presence is more difficult to obtain.
"A Text-Book of Astronomy"
George C. Comstock