An Elementary Treatise on Astronomy: In Two Parts. The First Containing, a Clear and Compendious View of the Theory; the Second, a Number of Practical Problems. To which are Added, Solar, Lunar, and Other Astronomical Tables ...

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Kimber & Sharpless, 1842 - 471 pages


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Page 15 - ... by an ether diffused through space; but if so, how happens it that the planets also have not been retarded ? This the' author attempted to show might be the case, although the phenomenon might pass unobserved.
Page 197 - ... before. This was the star in question. It was then as bright as Sirius, and continued to increase till it surpassed Jupiter when brightest, and was visible at mid-day. It began to diminish in December of the same year, and in March 1574, had entirely disappeared.
Page 80 - Year, and consists of 365 days, в hours, 9 minutes, and 9. 6 seconds, which is invariable. The Tropical Year is the interval between two consecutive returns of the Sun to the Vernal Equinox.
Page 18 - The azimuth of a body is the arc of the horizon intercepted between the north or south point of the horizon, and a vertical circle passing through the body.
Page 122 - The sidereal time of our common noon is given in the nautical almanac for every day in the year...
Page 14 - Mercury, Venus, the Earth, Mars, Vesta, Juno, Ceres, Pallas, Jupiter, Saturn, and Uranus, in the order here enumerated.
Page 196 - ... of these clusters are visible to the naked eye. In the cluster called the Pleiades, six stars are readily perceived by the naked eye, and we obtain glimpses of many more. With a telescope of moderate power 188 stars can be counted.
Page 306 - ... earth's atmosphere. With this radius describe the circle ADB about the centre C. Add the moon's semi-diameter to the radius CB, and with this sum for a radius, describe about the centre C a circle, which, if there be an eclipse, will cut NL in two points, E and H representing respectively the places of the moon's centre at the beginning and end of the eclipse. Draw the line CKR perpendicular to LN, and cutting it in K. The hours and minutes marked on the line LN, at the points E, K, and H, will...
Page 85 - The squares of the periods of the planets are proportional to the cubes of their mean distances from the sun ; that is, ti2 : k2 ,• ,• ai3 ,• (h3This is the so-called harmonic law.
Page 109 - That node where the planet passes from the south to the north side of the ecliptic, is called the ascending node ; and the other is the descending node.

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