Successful Exploration Through the Interior of Australia by William John Wills
page 41 of 347 (11%)
page 41 of 347 (11%)
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it rise. Its distance is 2850 millions of miles, and the sun as
seen by them is not larger than Venus appears to us when an evening star. And although this planet is so distant that it can only be seen with large telescopes, they can not only compute its distance and size, but also the mass of matter of which it is composed. But you will find all this thrown into the shade by the way in which it was discovered. As I may be telling you what you know already, I will merely state, that from observed perturbations in the course of the planet Uranus, it was supposed that another planet was in existence beyond it; and two competitors set to work to calculate its size, situation, etc. The result was, the discovery of this other planet within a few minutes of the place pointed out by them, and its size, etc., not very different from what they estimated it at. But besides this, astronomy includes matters more intimately mixed up with our everyday affairs. In the Nautical Almanacs, which are constructed for several years in advance, the situations and nearly everything connected with the different planets are calculated for every day in the year, and can be found, if required, for any minute in any day you please, for 10,000 years to come. Also the eclipses of the sun or moon, with the exact moment at which they will commence or end, at any spot on the earth; the exact portion eclipsed, or, in fact, anything about it you like to mention for any given number of years in advance. Not only this, but you can find the eclipses of Jupiter's moons with the same precision. Now is there anything to be compared with this? But if astronomy led to no other end than the mere gaining of knowledge, or the assistance of commerce, it would take a far lower stand than it is really entitled to. As the great object of the science is the correction of error and the investigation of truth, it necessarily leads all those that feel an interest in it to a higher |
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