Letters on Astronomy: Addressed to a Lady; in which the Elements of the Science are Familiarly Explained in Connexion with Its Literary HistoryMarsh, Capen, Lyon and Webb, 1841 - 419 |
Z wnętrza książki
Wyniki 1 - 5 z 60
Strona 21
... diameter on which the earth is conceived to turn in its diurnal revolution . The same line , continued until it meets the starry con- cave , constitutes the axis of the celestial sphere . The poles of the earth are the extremities of ...
... diameter on which the earth is conceived to turn in its diurnal revolution . The same line , continued until it meets the starry con- cave , constitutes the axis of the celestial sphere . The poles of the earth are the extremities of ...
Strona 30
... diameter , each degree will occupy one tenth of an inch . If the circle is twenty feet in diame- ter , a degree will occupy the space of two inches , and could be easily divided into minutes , since each minute would cover a space one ...
... diameter , each degree will occupy one tenth of an inch . If the circle is twenty feet in diame- ter , a degree will occupy the space of two inches , and could be easily divided into minutes , since each minute would cover a space one ...
Strona 31
... diameter , no greater than one fifty- seven hundredth part of an inch . To divide , or gradu- ate , astronomical instruments , to such a degree of nicety , requires the highest efforts of mechanical skill . Indeed , the whole art of ...
... diameter , no greater than one fifty- seven hundredth part of an inch . To divide , or gradu- ate , astronomical instruments , to such a degree of nicety , requires the highest efforts of mechanical skill . Indeed , the whole art of ...
Strona 33
... diameter will collect a beam of light of the same dimensions , and convey it to the eye . By these means , many obscure celestial objects become distinctly visible , which would otherwise be either too minute , or not sufficiently ...
... diameter will collect a beam of light of the same dimensions , and convey it to the eye . By these means , many obscure celestial objects become distinctly visible , which would otherwise be either too minute , or not sufficiently ...
Strona 34
... diameter , which give very clear and bright images . Such instruments are called achromatic tele- scopes , a name implying the absence of prismatic or rainbow colors in the image . It is , however , far more difficult to construct large ...
... diameter , which give very clear and bright images . Such instruments are called achromatic tele- scopes , a name implying the absence of prismatic or rainbow colors in the image . It is , however , far more difficult to construct large ...
Inne wydania - Wyświetl wszystko
Kluczowe wyrazy i wyrażenia
angle appear ascertain astronomers atmosphere attraction axis called celestial centre circle comet conjunction constellation degrees diameter direction discovery disk distance diurnal motion doctrine double stars earth ecliptic equal equator equinox exhibited fact fixed stars force Galileo globe gravity greater greatest half Halley's comet heavenly bodies heavens Hence Herschel horizon hundred inferior conjunction instrument John Herschel Jupiter Kepler latitude laws length less light longitude lunar lunar eclipse magnitude measure Mercury meridian meteors millions of miles minutes moon moon's motion move Nature nearer nearly node objects observations opposite orbit parallax passing perihelion period phenomena planetary planets pole respect revolve right ascension ring round satellites Saturn seen shadow side space spectator sphere sun's superior planets supposed surface telescope thousand tides tion truth Tycho Tycho Brahe universal gravitation Uranus velocity Venus vernal equinox visible west to east