Part 3 (1/2)
[Footnote 40: Bullialdus, _De Nebulosa Stella in Cingulo Andromedae_ (1667); see also G. P. Bond, _Mem. Am. Ac._, vol. iii., p. 75, Holden's Monograph on the Orion Nebula, _Was.h.i.+ngton Observations_, vol. xxv., 1878 (pub. 1882), and Lady Huggins's drawing, _Atlas of Spectra_, p.
119.]
[Footnote 41: _Mathemata Astronomica_, p. 75.]
[Footnote 42: _Systema Saturnium_, p. 9.]
[Footnote 43: _Phil. Trans._, vol. xxix., p. 390.]
[Footnote 44: _Mem. Ac. des Sciences_, 1755.]
[Footnote 45: _Conn. des Temps_, 1784 (pub. 1781), p. 227. A previous list of forty-five had appeared in _Mem. Ac. des Sciences_, 1771.]
[Footnote 46: _Phil. Trans._, vol. lxxiv., p. 442.]
[Footnote 47: _Ibid._, vol. lxxix., p. 213.]
[Footnote 48: _Ibid._, vol. lxxv., p. 254.]
[Footnote 49: _Ibid._, vol. lxxix., p. 225.]
[Footnote 50: _Phil. Trans._, vol. lxxix., p. 226.]
[Footnote 51: _Ibid._, vol. lx.x.xi., p. 72.]
[Footnote 52: _Ibid._, p. 85.]
[Footnote 53: _Phil. Trans._, vol. ci., p. 271.]
[Footnote 54: _Ibid._, p. 277.]
[Footnote 55: J. Herschel, _Phil. Trans._, vol. cxvi., part iii., p. 1.]
[Footnote 56: His own words to the poet Campbell cited by Holden, _Life and Works_, p. 109.]
[Footnote 57: _Phil. Trans._, vol. civ., p. 283.]
CHAPTER II
_PROGRESS OF SIDEREAL ASTRONOMY_
We have now to consider labours of a totally different character from those of Sir William Herschel. Exploration and discovery do not const.i.tute the whole business of astronomy; the less adventurous, though not less arduous, task of gaining a more and more complete mastery over the problems immemorially presented to her, may, on the contrary, be said to form her primary duty. A knowledge of the movements of the heavenly bodies has, from the earliest times, been demanded by the urgent needs of mankind; and science finds its advantage, as in many cases it has taken its origin, in condescension to practical claims.
Indeed, to bring such knowledge as near as possible to absolute precision has been defined by no mean authority[58] as the true end of astronomy.
Several causes concurred about the beginning of the last century to give a fresh and powerful impulse to investigations having this end in view.
The rapid progress of theory almost compelled a corresponding advance in observation; instrumental improvements rendered such an advance possible; Herschel's discoveries quickened public interest in celestial inquiries; royal, imperial, and grand-ducal patronage widened the scope of individual effort. The heart of the new movement was in Germany.
Hitherto the observatory of Flamsteed and Bradley had been the acknowledged centre of practical astronomy; Greenwich observations were the standard of reference all over Europe; and the art of observing prospered in direct proportion to the fidelity with which Greenwich methods were imitated. Dr. Maskelyne, who held the post of Astronomer Royal during forty-six years (from 1765 to 1811), was no unworthy successor to the eminent men who had gone before him. His foundation of the _Nautical Almanac_ (in 1767) alone const.i.tutes a valid t.i.tle to fame; he introduced at the Observatory the important innovation of the systematic publication of results; and the careful and prolonged series of observations executed by him formed the basis of the improved theories, and corrected tables of the celestial movements, which were rapidly being brought to completion abroad. His catalogue of thirty-six ”fundamental” stars was besides excellent in its way, and most serviceable. Yet he was devoid of Bradley's instinct for divining the needs of the future. He was fitted rather to continue a tradition than to found a school. The old ways were dear to him; and, indefatigable as he was, a definite purpose was wanting to compel him, by its exigencies, along the path of progress. Thus, for almost fifty years after Bradley's death, the acquisition of a small achromatic[59] was the only notable change made in the instrumental equipment of the Observatory. The transit, the zenith sector, and the mural quadrant, with which Bradley had done his incomparable work, retained their places long after they had become deteriorated by time and obsolete by the progress of invention; and it was not until the very close of his career that Maskelyne, compelled by Pond's detection of serious errors, ordered a Troughton's circle, which he did not live to employ.
Meanwhile, the heavy national disasters with which Germany was overwhelmed in the early part of the nineteenth century seemed to stimulate rather than impede the intellectual revival already for some years in progress there. Astronomy was amongst the first of the sciences to feel the new impulse. By the efforts of Bode, Olbers, Schroter, and Von Zach, just and elevated ideas on the subject were propagated, intelligence was diffused, and a firm ground prepared for common action in mutual sympathy and disinterested zeal. They received powerful aid through the foundation, in 1804, by a young artillery officer named Von Reichenbach, of an Optical and Mechanical Inst.i.tute at Munich. Here the work of English instrumental artists was for the first time rivalled, and that of English opticians--when Fraunhofer entered the new establishment--far surpa.s.sed. The development given to the refracting telescope by this extraordinary man was indispensable to the progress of that fundamental part of astronomy which consists in the exact determination of the places of the heavenly bodies. Reflectors are brilliant engines of discovery, but they lend themselves with difficulty to the prosaic work of measuring right ascensions and polar distances. A signal improvement in the art of making and working flint-gla.s.s thus most opportunely coincided with the rise of a German school of scientific mechanicians, to furnish the instrumental means needed for the reform which was at hand. Of the leader of that reform it is now time to speak.
Friedrich Wilhelm Bessel was born at Minden, in Westphalia, July 22, 1784. A certain taste for figures, coupled with a still stronger distaste for the Latin accidence, directed his inclination and his father's choice towards a mercantile career. In his fifteenth year, accordingly, he entered the house of Kuhlenkamp and Sons, in Bremen, as an apprenticed clerk. He was now thrown completely upon his own resources. From his father, a struggling Government official, heavily weighted with a large family, he was well aware that he had nothing to expect; his dormant faculties were roused by the necessity for self-dependence, and he set himself to push manfully forward along the path that lay before him. The post of supercargo on one of the trading expeditions sent out from the Hanseatic towns to China and the East Indies was the aim of his boyish ambition, for the attainment of which he sought to qualify himself by the industrious acquisition of suitable and useful knowledge. He learned English in two or three months; picked up Spanish with the casual aid of a gunsmith's apprentice; studied the geography of the distant lands which he hoped to visit; collected information as to their climates, inhabitants, products, and the courses of trade. He desired to add some acquaintance with the art (then much neglected) of taking observations at sea; and thus, led on from navigation to astronomy, and from astronomy to mathematics, he groped his way into a new world.