Contributions to Astro-Meteorology . 37 



The general results of Mr. Greg's investigations as regards 

 meteoric showers are thus summed up in the Report of the Com- 

 mittee on Luminous Meteors. 



" They appear to endure for almost any period, from twenty-four 

 hours to eight or possibly ten weeks, differing from one another in 

 richness or intensity of display. In some there appears to be a ten- 

 dency to maximum display on particular days, as, for example, xlvii, 

 lasting from November 26th to December 30th ; but the most abun- 

 dant display occurs from December 9th to 13th. In others no such 

 maximum can be perceived. Their number, of fully fifty as yet as- 

 certained, will probably not be much exceeded, unless by short-lived 

 showers, and by others whose radiants culminate just before dawn. 

 There is no confusion or chance in their return, but, on the contrary, 

 the showers are very regularly recurrent every year, and, allowing a 

 radiant region of 10° to 15° in diameter for each, the so-called " spo- 

 radic " meteors will become extremely scarce now that the principal 

 showers and their radiants have been pointed out. A well-marked 

 instance of long persistence and remarkable for having its radiant 

 very small and fixed is the shower of August 6th to September 10th, 

 No. xxix. The great majority have at the present time been as 

 clearly defined (as regards the time of their occurrence, duration, 

 and positions of their radiants) as in the case of the older and 

 better-known showers of August and November. On the average 

 of many years the radiant regions of a few are, however, still very 

 extensive. In all, a plane, oval, or double-headed region of radia- 

 tion appears to represent the conditions of the showers more cor- 

 rectly than a point. This elongation of the radiant region is in most 

 cases perpendicular to the ecliptic, or parallel to the via lactea, in 

 or near which the greater number of the radiants in the latter half 

 of the year are placed. The meteors of particular showers vary in 

 their distinctive characters, some being larger and brighter than 

 others, some whiter, some more ruddy than others, some swifter, 

 and drawing after them more persistent trains than those of other 

 showers. Their connexion with the epochs and directions of large 

 meteors still remains to be established." 



From a private letter by Mr. Greg to Mr. B. V. Marsh, we 

 learn that some minor changes are found necessary, by further 

 observation and investigation, in the duration of the showers and 

 the places of the radiants. Mr. Greg's charts containing the 

 paths of nearly two thousand shooting-stars are about to be pub- 

 lished by the British Association. We may hope to receive 

 them within a few months. We evidently need these charts in 

 order to discuss intelligently this important subject. While 

 waiting for them, however, one or two remarks may not be out 

 of place. 



That the so-called sporadic shooting-stars should belong 

 largely to rings or streams, as do the August and November 

 meteors, is in the present state of our knowledge probable, or 



