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Page:Popular Science Monthly Volume 18.djvu/202

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THE POPULAR SCIENCE MONTHLY.

some distinguishing titles or symbols to conveniently particularize either of them which it may be necessary to refer to. The method now adopted, of naming the chief periodical showers by the constellations in which their radiant points are situated, is very appropriate; and such displays as the Orionids, Leonids, and Geminids, have become so well known by their titles that it would be unwise and inconsistent to attempt reform. But with regard to the minor systems, which are becoming very numerous, and require an equally ready mode of expression, there is a great difficulty in avoiding complications.

There are certainly five nearly simultaneous showers of Perseids early in August; and in every month of the year, except May and June, meteors continue to fall from that constellation. If the present mode is adopted of styling them Perseids I, Perseids II, and so on progressively, a good deal of confusion must eventually arise as new systems are discovered; and this classification by Roman numbers, however appropriate it may be in some of its other applications, will have to give way to a more distinguishing means of reference. The name at present only gives indication of the constellation from which the meteors emanate, without regard to the date or approximate place of the radiant, and it seems to me that the difficulty may be obviated by including the nearest fixed star and the epoch with that name. To render the proposal clear, let us take the different streams proceeding from the undermentioned points in Perseus in August: 44° + 56°, 32° + 53°, 61° + 36°, 61° + 48°, 46° + 47°, which may be thus termed:

η Perseids (August 10th).
χ Perseids (August lst-3d).
ε Perseids (August).
μ Perseids (August).
α Perseids (August).

This is apparently a preferable method to that of Perseids I, II, III, IV, and V, which must occasion endless trouble in references to find what special stream is meant. Moreover, the numbers seem only in fair application when affixed progressively to the successive showers of the year, for it would be hardly consistent to call a radiant visible in Perseus early in January by the designation of, say, "Perseids XXXVIII." Yet this is what we are drifting to, unless a fresh system is introduced to accommodate the rapidly increasing number of meteor-streams.—Popular Science Review.