John Louis Emil Dreyer

“ Venus will make him pleasant, comely, and voluptuous, fond of music and the fine arts; Mars makes him brave and warlike, while Mercury adds cleverness and acuteness to his other faculties. He will be of a sanguine temperament, because nearly all the planets which indicate the temperament are in sanguine signs, but at the same time he will not be without some saturnine gravity. Venus, as the ruler, determines his character, and as Mars is joined to her, the prince will indulge too much in sensual enjoyment, but Mars in the sign of Mercury will make him generous and ambitious. ”

“ For a place not on the meridian of Greenwich the sidereal time at noon must be corrected by the addition or subtraction of 9" - 8565 for each hour of longitude, according as the place is west or east of Greenwich.
While it has for obvious reasons become customary in all civilized countries to commence the ordinary or civil day at midnight, astronomers count the day from noon, being the transit of the mean sun across the meridian, in strict conformity with the rule as to the beginning of the sidereal day. The hours of the astronomical day are also counted from to 24. ”

“ Under the green part of the tree a youth is seated, wearing a laurel wreath on his head and holding a star-globe and a book in his hands. Under the withered part of the tree is a table covered with money-boxes, sceptres, crowns, coats of arms, finery, goblets, dice, and cards, all of which a skeleton tries to grasp in its outstretched arms. Above is the pentameter, "Vivimus ingenio, cætera mortis erunt," pointing out the vanity of worldly things, while only earnest study confers immortality. ”

“ The observation of the time when a star has a certain azimuth may also be used for determining the clock error, as the hour-angle can be found from the declination, the latitude, and the azimuth. As the azimuth changes most rapidly at the meridian, the observation is most advantageous there, besides which it is neither necessary to know the latitude nor the declination accurately. In the article Geodesy (vol. x. p) it has been shown how the observed time of transit over the meridian is corrected for the deviations of the instrument in azimuth, level, and collimation. ”

“ For nearly two hundred years, until the application of the pendulum to clocks became general, astronomers could place little or no reliance on their clocks, and consequently it was always necessary to tix the moment of an observation by a simultaneous time determination. For this purpose Tycho Brahe employed altitudes observed with quadrants; but he remarks that if the star is taken too near the meridian the altitude varies too slowly, and if too near the horizon the refraction (which at that time was very imperfectly known) introduces an element of uncertainty. ”

“ MURAL QUADRANT.
of Seeland and Scania in the distance, helps to form very attractive scenery, which adds to the peculiar charm the island has for any one who is interested in the great memories connected with it. One can understand why Tycho calls it "Insula Venusia, vulgo Hvenna," as if it were worthy of being called after the goddess of beauty. ”

“ He even found out that Stadius had not computed his places correctly from Reinhold's tables. And already at that time, while Tycho was a youth only sixteen years of age, his eyes were opened to the great fact, which seems to us so simple to grasp, but which had escaped the attention of all European astronomers before him, that only through a steadily pursued course of observations would it be possible to obtain a better insight into the motions of the planets, and decide which system of the world was the true one. ”

“ Si Tycho fut resté dans son ile, jamais Kepler ne se fut rendu à ses invitations; nous n'aurions certainement pas la Théorie de Mars, et nous ignorerions peut-être encore le véritable système du Monde. ”

“ While many people admitted the influence of the stars on nature, they denied it where mankind were concerned. But man is made from the elements, and absorbs them just as much as food and drink, from which it follows that man must also, like the elements, be subject to the influence of the planets; and there is, besides, a great analogy between the parts of the human body and the seven planets. The heart, being the seat of the breath of life, corresponds to the sun, and the brain to the moon. ”

“ Being thus obliged to consider the matter more fully, Kepler did so in his reply, in which his wonderful genius displays itself by the way in which he suggests that the moon might be retarded in its motion by a force emanating from the sun, which would be greatest in winter, when the moon and earth are nearer to the sun than they are in the summer. ”

“ In the ancient free city of Augsburg Tycho seems to have felt perfectly at home. Dear to all Protestants as being the place where the fearless Reformers had declared their faith, and where the Protestant princes and cities of Germany had signed the "Confession of Augsburg," the city possessed the further attraction of having many handsome public and private buildings and spacious thoroughfares, while the society of many men of cultured tastes and princely wealth (such as the celebrated Fugger family) , made it an agreeable place of residence. ”

“ With this instrument Tycho measured the distance of the star from the nine principal stars of Cassiopea. We can easily picture to ourselves the impatience with which he must have awaited the next clear night, in order to see whether this most unusual phenomenon would still appear, or whether the star should have vanished again as suddenly as it had revealed itself. ”

“ Though the star was so near the equinoctial colure that it nearly touched it with its rays, it was quite within the vernal quadrant, and it announces that some great light is at hand, just as the sun when past the vernal equinox conquers the darkness of night. And as the star was visible over most of the earth, so the effects of it will be felt over the greater part of the globe, though the northern hemisphere will be especially affected. ”

“ Tycho could not but see that Vedel was only doing his duty, and Vedel gradually had to acknowledge that the love of astronomy had become so deeply rooted in his pupil that it was utterly impossible to force him against his will to devote himself to a study he disliked, or at least looked on with indifference. Another circumstance which was a bond of union between them was that the learned men whose society Vedel sought were to a great extent the same to whom Tycho looked for instruction. ”

“ We have now followed Tycho through what may be considered the first period of his life. By study and intercourse with learned men he had mastered the results of the science of antiquity and the Middle Ages. But though he had to some extent already, as a youth seventeen or eighteen years of age, perceived the necessity of a vast series of systematic observations on which to found a new science, he had hitherto shrunk from carrying out this serious undertaking himself, or had perhaps despaired of getting the means of doing so. ”

“ Many philosophers and theologians, continued Tycho in his lecture, have contended that astrology was not to be counted among the sciences, because the moment of birth was difficult to fix, because many are born at the same moment whose fates differ vastly, because twins often meet with very different fortunes, while many die simultaneously in war or pestilence whose horoscopes by no means foretold such a fate. ”

“ He believes experience to have shown that those who are born when the moon is affected by the evil planets (Saturn and Mars) and is unluckily placed, have a weak brain and are under the influence of passions, while those in whose case the sun was influenced by those planets suffered from palpitation of the heart. But if both luminaries are in unlucky aspects, those born at that time are of weak health and intellect. Those people at whose birth Saturn, the highest planet, was favourable, are inclined to sublime studies, while those whom Jupiter has influenced are attracted to politics. ”

“ It is much to be regretted that we are utterly unacquainted with the manner in which Copernicus came to design the new system of astronomy which has made his name immortal. But he had probably early perceived that, however valuable the labours of Regiomontanus had been, they had not improved the theory of celestial motion, so that the most important problem, that of computing beforehand the positions of the planets and accounting for their apparently intricate movements, was practically untouched since the days of Ptolemy. ”

“ But, regardless of the duties imposed on him by his station, the Emperor reluctantly devoted a moment to business of any kind, while he willingly gave his time and the limited pecuniary means of his impoverished dominions to collecting art treasures and promoting science—the real science represented by Tycho and Kepler, as well as the imaginary ones taught by the disciples of Cornelius Agrippa and Cardanus. Prague, where he usually resided, was not a very favourable place for the growth of science and art, as Bohemia had never settled down since the Hussite disturbances. ”