Elements of astronomy: accompanied with numerous illustrations, a colored representation of the solar, stellar, and nebular spectra, and celestial charts of the northern and the southern hemisphere (1875)
Lockyer, Norman, Sir, 1836-1920 · New York, D. Appleton and company · leaf 243
ceives a thousand times morelight; and consequently the imageof a star formed at its focus is nearlya thousand times brighter than thatthrown by the lens of our eye onthe retina. We say nearly a thou-sand times, because some light is lostby reflection from the object-glass and during the passage… … in the construction of the telescope? Explain this further with Fig. 96. 429. Onwhat does the efficiency of the telescope depend ? How does the telescope getits illuminating power? How is some of the light that falls on the object-glass THE TELESCOPE. 237 430. Magnifying Power.—The Magnifying Power…
Astronomy
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
