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 5
... opposite side of the earth , up , as regards space , or the heavens , is in a direction exactly contrary from what it is to us ; for a right line which is down to us , if continued through , and beyond the opposite side of the earth ...
... opposite side of the earth , up , as regards space , or the heavens , is in a direction exactly contrary from what it is to us ; for a right line which is down to us , if continued through , and beyond the opposite side of the earth ...
Page 7
... opposite the sun moves from the right hand to the left : that is , the diurnal motion of the side of the earth next the sun , is in an opposite direction to the annual motion of the earth in its orbit round the sun ; and the diurnal ...
... opposite the sun moves from the right hand to the left : that is , the diurnal motion of the side of the earth next the sun , is in an opposite direction to the annual motion of the earth in its orbit round the sun ; and the diurnal ...
Page 8
... opposite side , is caused by the moon's being in the earth's shadow ; that is , the earth being directly between the sun and moon , prevents the sun from shining on the moon . An eclipse of the sun , which can happen only at the time of ...
... opposite side , is caused by the moon's being in the earth's shadow ; that is , the earth being directly between the sun and moon , prevents the sun from shining on the moon . An eclipse of the sun , which can happen only at the time of ...
Page 9
... opposite point to that in which the earth is ; in con- structing tables of motion , the sun is considered to move in the ecliptic round the earth once a year , though the fact is otherwise , yet every appearance is the same as if this ...
... opposite point to that in which the earth is ; in con- structing tables of motion , the sun is considered to move in the ecliptic round the earth once a year , though the fact is otherwise , yet every appearance is the same as if this ...
Page 12
... opposite to him , sooner , or in less time , than she could if his motion were uniform and equal ; and when his anomaly is more than six signs , that is , while he is moving from his perigee to his apogee , his true place being before ...
... opposite to him , sooner , or in less time , than she could if his motion were uniform and equal ; and when his anomaly is more than six signs , that is , while he is moving from his perigee to his apogee , his true place being before ...
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.