It is no solitary example. Particular association, indeed—as was surmised by Michell far back in the eighteenth century—appears to be the rule rather than an exception in the sidereal system. Stars are bound together by twos, by threes, by dozens, by hundreds. Our own sun is, perhaps, not exempt from this gregarious tendency. Yet the search for its companions has, up to the present, been unavailing. Gould's cluster[1629] seems remote and intangible; Kapteyn's collection of solar stars proved to have been a creation of erroneous data, and was abolished by his unrelenting industry. Rather, we appear to have secured a compartment to ourselves for our long journey through space. A practical certainty has, at any rate, been gained that whatever aggregation holds the sun as a constituent is of a far looser build than the Pleiades or Præsepe. Of all such majestic communities the laws and revolutions remain, as yet, inaccessible to inquiry; centuries may elapse before even a rudimentary acquaintance with them begins to develop; while the economy of the higher order of association, which we must reasonably believe that they unite to compose, will possibly continue to stimulate and baffle human curiosity to the end of time.
FOOTNOTES:
[1369] Report Brit. Assoc., 1868, p. 166. Rutherfurd gave a rudimentary sketch of a classification of the kind in December, 1862, but based on imperfect observation. See Am. Jour. of Sc., vol. xxxv., p. 77.
[1370] Publicationem, Potsdam, No. 14, 1884, p. 31.
[1371] Von Konkoly once derived from a slow-moving meteor a hydro-carbon spectrum. A. S. Herschel, Nature, vol. xxiv., p. 507.
[1372] Phil. Trans., vol. cliv., p. 429.
[1373] Am. Jour. of Sc., vol. xix., p. 467.
[1374] Photom. Unters., p. 243.
[1375] Spectre Solaire, p. 38.