542 



NATURE 



[October 7, KS97 



meteor of the same appearance seen at gh. lom. by Mr. Norman 

 Lattey at Cardiff (^;7^//V/4 Mechanic, vol. Ixvi. p. 15. August 20, 

 1897), if it had left a streak, and had not seemed to move rather 

 more slowly overhead than the swift- flighted Perseids. The 

 height of its path above the earth would be from 135 to 1 15 

 miles if the two meteors really were identical ! A more ordinary 

 height of from 81 to 47 miles, was found by Mr. Denning from a 

 second observation of it at ikidgwater, by Mr. Corder, for the 

 non-Perseid fireball seen here at I3h. 57m. on August 2. This 

 meteor lit up the sky brightly with two concluding flashes, and 

 left a greenish light-streak on the latter portion of its course, 

 visible for 6 seconds. Its radiant-point was found by Mr. 

 Denning, from the double observation, to have been between 

 Aquarius and Aquila, at 312°, ± 0°, on the equator. 



Although the watch was not maintained steadily on all fine 

 nights, nor very often for many hours together on the single 

 nights, yet some good views of further frequencies of the 

 Perseids, with definite centres of radiation, were obtained after 

 the first display from v, (p Persei on July 22, and were pretty 

 successfully recorded. The latter centre remained active until 

 July 27 (when it was again conspicuous), and then ceased, giving 



Fig. I.— Path-I: 



of Perseid Meteors belonging to Radiants I. (u, <f,); II. (4); III.(x); and IV. (rj, 

 Persei) ; and V. (B, C Camelopardi) ; July 22-August g, 1897.1 



place to a second centre between <}> and x> near 4 Persei, at 

 about 27°, + 53° ; although a few Perseid meteors still now and 

 then appeared to come from the earlier radiant-point jDosition 

 in some later watches. 



The second centre was first well marked on July 30, but it was 

 most active on the beautifully clear night of August 2, with very 

 well-defined radiation from aljout 30", + 54°, and with another 

 well-defined and nearly as productive centre near it at 35°, + 56°, 

 whose meteors were afterwards grouped with others (chiefly on 

 August 8) into shower III., at 36°, -f 55°. On the two equally 

 fine nights of July 31 and August I, although sporadic meteors 

 were most plentiful, yet three and four Perseids only were noted, 

 in watches of 2^ hours, against 12 Perseids in the time of watch 

 between the same hours on the later night ; and of the twenty 

 Perseids mapped in 4 hours then, 10 and 6, respectively, pro- 



1 Circles of Longitude and Latitude are shown by dotted lines (and by 

 figures for every 10°, enclosed in brackets) ; and circles of Declination by 

 full lines. But to prevent their confusion with path lines, and their ob- 

 structing the view of the path-lines' radiations, the close array of R.A. 

 Meridian-lines is omitted, and the scale of righl-a.vcension is only noted, 

 like the Declination-circles, in plain figures for every 10°, round the border 

 of the Map. 



ceeded very accurately from the above two companion radiant- 

 points ! Like the first shower from <p Persei, the immediately 

 succeeding one at 4 Persei ended in its turn on August 3, and 

 produced only three meteors afterwards on later dates ! 



Clouds prevented observations on August 5 and 7, but an 

 hour's watch on August 6 showed that the usual stream of 

 Perseids from the well-known radiant-point in Perseus was 

 approa.ching, as four of the six Perseids recorded then, diverged 

 very distinctly from close round B, C Camelopardi. 



In watches of two, and of four or five hours' duration, until 

 daybreak, on the nights of August 8 and 9, 42 Perseid and 37 

 sporadic meteor tracks were mapped at only the very moderate 

 rates, for so near the epochal date, of eight or nine Perseids per 

 hour in the closing moonless hours of the two nights' watches ; 

 the abundance of the Perseids on the mornings of August 9 and 

 10, in fact hardly exceeding the rate very perceptibly (of 7 per 

 hour), which had already been noted a week previously at a 

 similar time of watch on the morning of August 3 ! On the 

 night of August 10 itself, the clouded state of the sky in England, 

 generally deprived observers here of a view of the shower's 

 appearance on its chief annual date ; but from a list of 92 meteor- 

 tracks mapped with nearly cloud- 

 less sky in 5^ hours on that 

 night, at Le Havre, in France, 

 which I received from a Mjember 

 of the Astronomical Society of 

 France, M. Libert, who records 

 appearances of shooting-stars and 

 fireballs at that nearly adjacent 

 continental town to English 

 stations, with extreme care and 

 diligence, sporadic meteors 

 seemed still to be greatly out- 

 numbering the Perseids, as they 

 did here less strongly on the 

 morning of the lOth, in the pro- 

 portion of nearly two to one, if 

 even allowances most favourable 

 to the Perseids are always made 

 in cases where indistinctness of 

 mapping made the radiation 

 doubtful. Substitutions of point- 

 ing-stars for the points of first 

 appearance and disappearance, 

 and the abnormal lengths of 

 path thus often noted, which 

 chiefly produced uncertainty in 

 the attempt to assign the meteors 

 their true radiant sources, also 

 prevented any exact positions 

 of the shower's chief centres of 

 divergence on that night from 

 being extracted from the im- 

 portantly supplied particulars, 

 otherwise, of M. Libert's very 

 valuable and cxtansive list of 

 path-descriptiors 



In point of brightness, how- 

 ever, with seven first-magnitude 

 meteors, and two equal to Sirius or Jupiter, and two compared 

 to Venus, the 25-30 Perseid shooting-stars described by M. 

 Libert, outshone the 60-65 sporadic meteors, at Le Havre, with 

 their ten of first magnitude and only one each as bright as 

 Sirius and Venus, about as brilliantly as the 28 Perseids noted 

 here on August 9, with six first-magnitude meteors and one or 

 two each as bright as Sirius and Venus, exceeded the abundance 

 {p7-o raid, or doubling the actual numbers here) of bright 

 meteors appearing among the 26 contemporaneously observed 

 non-Perseid shooting- stars, with three first-magnitude, one 

 Sirius-like, and (possibly) one brighter meteor than Venus, 

 which, however, so nearly came within the range of radiation of 

 the Perseids that it is also counted in the category above, as 

 possibly a Perseid fireball. 



The shower had not yet subsided in numbers or in brightness, 

 it appears, when the strength of the full moon's light had 

 deterred me from looking out for it any longer, on the night of 

 August II : for in the hour and a half from loh. 20ni. to lih. 

 50m. on that night, Mr. J. A. Hardcastle noted at Lymington, 

 in Hants, the paths of ten Perseids and five sporadic shooting- 

 stars, with two of first magnitude among the former, but none 



NO. 1458. VOL. 56] 



