OcTOIiKR 29, 1896] 



NA TURE 



623 



insulated electrode of a quadrant electrometer. Through 

 a second paraffin tunnel, at the other end of the filter, 

 and a connecting pipe, the air is drawn off by an air- 

 pump. All the metal of the apparatus, except the filter, 

 and except the electrometcr-vane, is connected with the 

 metal case of the electrometer. 



We were much interested to find, as we expected, that the 

 steam ga\ c up a larjje part of its electricity to be carried 

 away by the air, while it itself was left behind in the 

 Wolffs bottle and the sulphuric pumice. We tried the 

 experiment both with positive and negative electrification, 

 and found it equally successful in the two cases. 



A full description of the experiment, with drawings 

 representing the apparatus, is given in a paper, on the 

 electrification of air and other gases, which we hope to 

 communicate to the Royal Society at its first meeting in 

 November. 



THE NOVEMBER METEORS. 

 A S the lapse of time brings us nearer to the maximum 

 -'*■ of these phenomena, the interest in this branch of 

 astronomy is intensified, and our liveliest expectations 

 encouraged. These meteors only return in their richest 

 abundance once in thirty-three years, so that the spectacle 

 they afford can only be witnessed once in a generation. 

 It is true that the shower may be manifested in a pretty 

 conspicuous manner in several successive years, but only 

 one really brilliant exhibition is usually seen, as on the 

 mornings of November 13, 1799, and 1833, and November 

 14, 1866. Two years before the maximum and three 

 years after it, striking displays have occurred, and show 

 that the orbit of the meteors is very thickly strewn with 

 these bodies over a considerable arc, since it takes six 

 years for them to cross the earth's track, though travelling 

 at the rate of about twenty-six miles per second. 



?2\ ery one who has watched a great meteoric display, 

 will admit that there is no other celestial spectacle which 

 can compare with the striking aspect it presents. Those 

 who have seen an event of this kind often recall its vivid 

 characters, and look forward to the prospect of re- 

 observing it. Others who have never witnessed it have 

 heard or read the descriptions of people who have been 

 more fortunate, and are anxious to behold so impressive 

 and wonderful a phenomenon. Apart from being an 

 attractive sight to the popular eye, it is a most important 

 event from a scientific point of view, and the regular 

 recurrence of this fine shower has been the means of 

 largely augmenting our know ledge of meteoric astronomy. 

 The all-important question now is, "' Will the display 

 be repeated this year in an imposing form, and merit close 

 attention from the casual obser\er as well as the pro- 

 fessional astronomer ?" A definite answer can scarcely 

 be given, for our knowledge of this particular system of 

 meteors is not sufficiently extensive to enable us to speak 

 with certainty. Changes are doubtless affecting the 

 stream, and the effects are cumulative ; thus the circum- 

 stances attending the ensuing return will be somewhat 

 different to those which controlled those of 1833 and 

 1866. The meteors are probably lengthening out along 

 the orbit owing to the differences in periodic time 

 amongst them, and the stream is widening as an effect 

 of planetary perturbation. Thus in future ages the 

 shower will probably return in many consecutive years 

 near the epoch of maximum, while the maximum itself 

 w ill be less brilliant than in former times, unless, indeed, 

 on an occasion when the earth crosses the meteor orbit 

 at a point very near the parent comet of Tempel (1866 I.) 

 forming " the gem of the ring." The show er will prob- 

 ably last for several weeks in a feeble character, owing to 

 the disturbances set up by the earth during its frequent 

 immersions in the stream. The latter must evidently be 

 undergoing a gradual process of thinning out, since our 

 atmosphere destroys by combustion such of the particles 

 as enter into it, and the number so destroyed must 



NO. 1409, VOL. 54] 



amount to many millions whenever a rich shower occurs.- 

 Still, in comparison with the enormous number of 

 meteors comprised in the whole system, the proportion 

 caught and vapourised by the earth nmst be extremely 

 insignificant. After a long series of years the Leonid 

 display, like that from Perseus in August, will probably 

 become a pretty rich annual shower, and lose much of 

 the grandeur which has attended it at intervals of about 

 thirty-three years in the past. 



From various observations obtained in November 

 1895, there was no sign of development in the Leonid 

 meteor shower. The number seen did not exceed those 

 counted in 1879 and 188S, when we were much further 

 removed from the maximum. On the morning of 

 November 14, not more than five Leonids per hour were 

 counted at any station in England, and the display was 

 therefore of very ordinary character. If, however, it failed 

 as regards numbers, it exceeded expectation in respect to 

 duration, for on the morning of November 17, Mr. 

 Corder saw twelve Leonids out of twenty-two meteors 

 counted in the two hours between 4h. 15m. and 6h. 15m. 

 a.m., and on November 18, he observed eight Leonids 

 out of thirty meteors seen in three hours between 2h. 

 and 5h. a.m. Next month there is a far greater prob- 

 ability that we shall see a display at least much above 

 the average, as w-e are twelve months nearer the maximum 

 epoch, and this should make all the difference. But as 

 we cannot expect the richest exhibition until 1899, we 

 are still three years in ad\ance of the important time, 

 and are scarcely justified, from the prevailing con- 

 ditions, in anticipating a brilliant revival of the shower 

 this year. Conspicuous displays occurred in 1831 and 

 1864, two years before maxima, and in 1897 the shower 

 is likely to develop, considerable strength, increasing in 

 1898, and culminating in 1899. In 1863, three years 

 prior to the magnificent return of 1866, not a great 

 number of meteors were seen, but there is evidence that 

 the Leonids formed a tolerably important shower. Mr. 

 T. M. .Simpkiss, of Wolverhampton, counted about ninety 

 meteors in one and a half hours between midnight and 

 ih. 30m. a.m. on November ij, 1863, and from their 

 streaks and directions it was evident the majority of 

 them emanated from the constellation Leo. Very few- 

 were observed on the nights of the 12th and 13th, and 

 during the hour from lih. to I2h. on November 14, Mr. 

 Simpkiss had only counted ten meteors. 



The prospect is a fair one that the shower will 

 return on the mornings of November 14 or 15. There 

 appears, however, to be little probability that it will be 

 very brilliant ; but it is likely to furnish forty or fifty 

 meteors an hour at the time of its best presentation, and 

 to rival a fairly active return of the Perseid shower. It 

 will be most important to watch its progress, to deter- 

 mine the degree of its activity and length of duration. 

 From my observations in past years, the Leonid radiant 

 appears to be feebly visible from November g to 

 November 19, and may be extended beyond those dates. 

 This year the moon will partly interfere with observ- 

 ation setting as follows : — 



12 50 



13 59 



16 19 



d. h. 



7 5 



8 5 



9 5 



10 5 



11 5 



Watches for shooting-stars should therefore be com- 

 menced at midnight on the morning- of the 13th, at 

 I a.m. on the 14th, at 2 a.m. on the 15th, and at 3 a.m. 

 on the 16th. Amongst the features to be specially 

 observed during the progress of the shower may be 

 enumerated the following : — 



f I ) The time of maximum frequency. 



(2) The horary number of Leonids visible. 



