A New Treatise on Astronomy, and the Use of the Globes, in Two Parts ... |
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Common terms and phrases
61 Cygni analemma angle of position aphelion apparent diameter astronomical sign axis azimuth brass meridian called Cape centre circle to 12 comet Draw the diagram earth east eccentricity Elevate the pole equal equator equinox fixed stars geographical miles given day given place globe westward greatest Gregorian calendar heavenly body heavens hemisphere hence horizon hour circle hourly motion inclination index has passed inferior conjunction John Herschel Jupiter length longest day longitude lunar eclipse magnitude mean distance Mercury meridian altitude moon nearly node noon north or south north pole number of degrees o'clock oblique ascension observed opposite orbit parallax parallel of latitude perihelion period planet PROBLEM quadrant of altitude radius revolution round right ascension rising and setting satellites Saturn set the index siderial revolution solar eclipse sun and moon sun rises sun's declination sun's place telescope tides tion tude turn the globe Uranus Venus vernal equinox western edge
Popular passages
Page 198 - If both the places be situated on the same parallel of latitude, their bearing is either east or west from each other ; if the'y be situated on the same meridian, they bear north and south from each other ; if they be situated on the same rhumb-line, that rhumbline is their bearing : if they be not situated on the same rhumb-line, lay the quadrant of altitude over the. two places, and that rhumb-line which is the nearest of being parallel to the quadrant will be their bearing.
Page 299 - ... to 12 ; then, if the given time be before noon ; turn the globe eastward on its axis till the index has passed over as many hours as the time wants of noon...
Page 282 - Bring the sun's place to the eastern edge of the horizon ; and all the stars along that edge of the horizon will rise cosmically, while those along the western edge will set cosmically.
Page 279 - ... to 12 ; then, if the time be after noon, turn the globe westward on its axis, till the index has passed over as many hours as the time is past noon ; but, if the time be before noon, turn the globe eastward till the index has passed over as many hours as the time wants of noon...
Page 301 - IV.) comes to the eastern edge of the horizon, and the hours passed over by the index will show...
Page 209 - ... 12. Turn the globe eastward till the given place comes to the horizon, and the index will shew the time of the sun's rising.
Page 232 - XX.) bring it to the brass meridian, and observe the degree above it ; turn the globe on its axis till some other point of the ecliptic falls under the same degree of the meridian : find this point of the ecliptic on the horizon, and directly against it you will find the day of the month required. This Problem may be performed by the celestial globe in the same manner.
Page 291 - Bring the sun's place in the ecliptic for the given day to the meridian, and set the index to XII. at noon : turn the globe westward till the index points to the given hour ; then the surface of the globe represents the exact face of the heavens at the given place.
Page 258 - Stick a needle in the parallel of the sun's declination for the given day,* and turn the globe on its axis till the needle casts no shadow : fix the globe in this position, and screw the quadrant of altitude over the latitude ; bring the graduated edge of the quadrant to coincide with the sun's place, or the point where the needle is fixed, and the degree on the horizon will show the azimuth.
Page 206 - A particular place, and the hour of the day at that place being given, to find what hour it is at any other place. RULE. Bring the place at which the time is given to the brass meridian, and set the index of the hour circle to 12 ; turn the globe till the other place comes to the meridian, and the hours passed over by the index will be the difference of time between the two places. If the place where the hour is sought lie to the east of that wherein the time is given, count the difference of time...