A New System of Practical Astronomy: Made Plain and Easy to Those who Have Not Studied Mathematics : Containing the Elementary Principles of the Science, All the Rules and Tables Necessary for Making All the Calculations for an Almanac ... |
From inside the book
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Page 8
... moon is of itself , a dark body , and shines only by reflecting the light of the sun . It is a globe 2180 miles in ... Full moon , the sun being on one side of the earth , and the moon nearly on the other , we see nearly all that part ...
... moon is of itself , a dark body , and shines only by reflecting the light of the sun . It is a globe 2180 miles in ... Full moon , the sun being on one side of the earth , and the moon nearly on the other , we see nearly all that part ...
Page 9
... Full Moon , for the moon will then be nearly on a level , or in the same plane with the earth and sun . At new moon , the sun and moon , as seen from the earth , always have the same lon- gitude and are always at the same distance from the ...
... Full Moon , for the moon will then be nearly on a level , or in the same plane with the earth and sun . At new moon , the sun and moon , as seen from the earth , always have the same lon- gitude and are always at the same distance from the ...
Page 11
... moon were always uniform and equal in one part of their orbit to what they were in any other part . But this is not ... full moon never coincides with the true , except when the anomalies of both the sun and moon are either nothing or ...
... moon were always uniform and equal in one part of their orbit to what they were in any other part . But this is not ... full moon never coincides with the true , except when the anomalies of both the sun and moon are either nothing or ...
Page 12
... moon , is the reason their mean and trus aces differ : for the same reason , the time of mean syzygy differs from ... full moon , on account of the sun's unequal motion , and unequal distance from the earth and moon , is 4h . 10m . 57s ...
... moon , is the reason their mean and trus aces differ : for the same reason , the time of mean syzygy differs from ... full moon , on account of the sun's unequal motion , and unequal distance from the earth and moon , is 4h . 10m . 57s ...
Page 27
... Moon in March . A Day is the time in which the earth turns once round on its axis ; or it is the time from one noon ... full moon to the next , which is 29 days , 12 hours , 44 minutes , 2.8283 seconds . The solar month is the time in ...
... Moon in March . A Day is the time in which the earth turns once round on its axis ; or it is the time from one noon ... full moon to the next , which is 29 days , 12 hours , 44 minutes , 2.8283 seconds . The solar month is the time in ...
Common terms and phrases
altitude angle aphelion apogee appear argument astronomers cask centre circle diameter difference diurnal motion divide dominical letter draw ecliptic Epact equal equator equinox fixed star Frustum Full Moon given side heavenly bodies heavens horizon Horizontal Parallax Hourly Motion inferior planets Jupiter Leap leap-year length less logarithm longitude and anomaly lunation mean longitude mean motion Mean New Moon meridian miles minutes month Moon's Ascending Node moon's mean anomaly moon's orbit moves round nearest noon number of days number of degrees numbers for March opposite Parallax perigee perpendicular point of aries pole PROB quotient radius remainder revolve round right ascension right line round the earth round the sun RULE Saturn secant seen Semidiameter Semidiurnal arc signs sine solar station subtract sun and moon sun's declination sun's mean anomaly sun's place Table tangent triangle true Longitude true syzygy Venus vernal equinox
Popular passages
Page 33 - No objection, says he, ariseth to that great luminary being inhabited ; vegetation may obtain there, as well as with us. There may be water and dry land, hills and dales, rain and fair weather, and as the light, so the season, must be eternal, consequently it may easily be conceived to be by far the most blissful habitation of the whole system.
Page 9 - The circumference of every circle is supposed to be divided into 360 equal parts, called degrees ; each degree into 60 equal parts, called minutes ; and each minute into 60 equal parts, called seconds.
Page 36 - ... below, seem to bid defiance to the laws of gravitation. Around the base of these frightful eminences, are strewed numerous loose and unconnected fragments, which time seems to have detached from their parent mass ; and when we examine the rents and ravines which accompany the over-hanging cliffs, we expect every moment that they are to be torn from their base, and that the process of destructive separation which we had only contemplated in its effects, is about to be exhibited before us in tremendous...
Page 40 - ... escape all observation, by reason of their paths traversing only that part of the heavens which is above the horizon in the daytime. Comets so circumstanced can only become visible by the rare coincidence of a total eclipse of the sun, a coincidence which happened, as related by Seneca, 60 years before Christ, when a large comet was actually observed very near the sun.
Page 4 - Instead, then, of one sun, and one world only in the universe, as the unskilful in astronomy imagine, that science discovers to us, such an inconceivable number of suns, systems, and worlds, dispersed through boundless space, that if our sun, with all the planets, moons, and comets, belonging to it, were annihilated, they would be no more missed by an eye that could take in the whole creation, than a grain of sand from the seashore ; the space they possess being comparatively so small, that it would...
Page 31 - ... but are variously affected by the action of the sun, which brings them on sooner, when the moon is in her first and third quarters ; and keeps them back later, when she is in her second and fourth. Because in the former case the tide raised by the sun .alone would be earlier than the tide raised...
Page 40 - ... must be at least many thousands. Multitudes, indeed, must escape all observation, by reason of their paths traversing only that part of the heavens which is above the horizon in the day-time.
Page 70 - The tropics are two small circles parallel to the equator at the distance of 23° 28' from it ; the northern, is called the tropic of cancer, and the southern, the tropic of Capricorn.
Page 36 - The climate of the moon must be very extraordinary : the alternation being that of unmitigated and burning sunshine, fiercer than an equatorial noon, continued for a whole fortnight, and the keenest severity of frost, far exceeding that of our polar winters, for an equal time.
Page 3 - that Copernicus, seized with a daring enthusiasm, laid his hands on the cycles and crystal orbs of Ptolemy, and dashed them to pieces. And that with the same noble phrenzy, he took the unwieldy earth, and sent her far from" the centre of the system, to move round the sun with the rest of the planets.