Sept. II, 1879] 



NATURE 



457 



or semi-erect, but as far as I could observe nearly all the teeth 

 came into pTay. When on fishing excursions in the lagoon, the 

 sharks which constantly carried off the bait, were often caught, 

 and in order to extract the hooV, a large log, constantly carried 

 in the boats for this purpose, was threateningly presented to its 

 face, and |of "course instantly seized and held on to for as Ion" 

 as it took to perform the operation of extraction. If, when the 

 fish is qnite recently dead, pressure be made on the angle of the 

 jaw, it is easy to observe the action of the rows of teeth. 

 Kesala, Bantam, Java, July Henry O. Forbes 



A Lunar Rainbow 



Last evening, September 3, at 10.40, a lunar rainbow was 

 visible at Llanfairfechan, in a north-west direction. The arc 

 was continuous, and of a brilliant white light It appeared to 

 stretch across Anglesey from Beaumaris to Puffin Island. The 

 bow did not last more than 2' from the time it was first observed 

 by us. F. E. Kitchener 



Llanfairfechan, September 4 



A Habit of Cattle 



In the colony of Natal the cattle have an extraordinary liking 

 for bones. They will stand for hours with a bone in the mouth 

 quietly munching, sucking, or perhaps more correctly speaking, 

 levigating the bone with the tongue. I have not heard that 

 cattle have the same habit in the other colonies of South Africa, 

 but I have been told that cattle exhibit the same taste in some 

 parts of South Australia. 



In Natal there is, I believe, a scarcity of chalk and limestone 

 in the geological formation. Will this fact account for the 

 habit ? Do the cattle lick bones in search of lime ? 



Can any of your readers account for this strange taste in 

 cattle? 



I may mention that horses and other herbivorous animals in 

 Natal do not exhibit the same taste. H. C. Donovan 



Delagoa Bay, July 20 



THE AUGUST PERSEIDS 



'TTHIS remarkable meteor shower recurring annually 

 •*• on August 10 is looked for every year with increasing 

 diligence. To Quetelet belongs the credit of having first 

 (in 1835) ascertained the epoch of its maximum display, 

 though the month of August had long been known as one in 

 which there was an abundance of falling stars. As early 

 as 1762 Muschenbroek, in his work on "Natural Philo- 

 sophy," stated that, according to his own observations, 

 there were more shooting stars in August than at any 

 other period of the year, and his remark is perfectly true 

 applied to the first half of that month, though it is ques- 

 tionable whether the last half of August will bear com- 

 parison with that of July, when meteors fall very plenti- 

 fully, and constitute a periodical display of special note 

 on the 27th- 3 1 St. Since Quetelet determined the date of 

 the Perseids, they have been expected every year with 

 great interest, and from the time that Heis first began 

 systematically to register the paths of meteors (nearly 

 half a century ago) to the present day, observers have 

 contitiued to record the successive apparitions of this 

 prominent star-shower, so that multitudes of its meteors 

 are now accumulated in the catalogues of British and 

 foreign astronomers. 



These Perseids appear to have belonged to our system 

 at a very remote epoch, and to have been observed in 

 considerable intensity as far back as the ninth century of 

 our era. They form a continuous ring or zone of particles. 

 The stream may vary in richness, that is to say, the 

 particles may be very unequally distributed along the 

 orbit, but it seems imbrokcn and manifests itself every 

 year with more or less intensity from its accustomed point, 

 yielding many bright meteors of great swiftness, and 

 almost invariably accompanied by phosphorescent streaks. 

 It was from careful observations of the Perseids that 

 Schiaparelli, in 1866, was led to his theory of the connec- 



tion or identity of comets and meteors, and the first 

 orbital coincidence foimd was that of the Perseids with 

 Comet III. 1862, which seems to have been merely the 

 nucleus or condensation of the particles forming this 

 remarkable rneteor system. ' 



The annual returns of this shower as observed and 

 described by various observers, when compared together, 

 show that in certain years the display is exceptionally 

 brilliant ; in others it is far less imposing. Eduard Heis, 

 at Miinster, counted 155 meteors per hour on August 10, 

 1863, yet on the same night in 1867 the figures had fallen 

 to 24 per hour. He gives the following as the horary 

 numbers derived from observations between loh. and 

 I2h. at several stations in Germany on August 10 in dif- 

 ferent years : — 



^^l Year. Station. "^t. 



.. 47 1863 ... Miinster ... 155 



.. 60 1863 ... Gae.sdonck ... 215 



■• 55 1863 ... Peckeloh ... 109 



.. 37 1864 ... Gaesdonck ... 106 



,. 89 1864 ... Rom 63 



.. 56 1867 ... Miinster ... 24 



.. 88 1867 ... Peckeloh ... 39 



.. 78 1867 ... Papenburg ... 44 



,. I02 1871 ... Peckeloh ... 93 



,. 102 1872 ... Rom 64 



,. 89 1874 ... Rom 110 



Maximum in 1863, minimum in 1867 and iSjo. There 

 were also many Perseids in 1839, when Heis counted 160 

 per hour. The displays of 1863 and 1871 were of consider- 

 able intensity. On August 10, 1863, gh. to I3jh., Heis, 

 assisted by several other observers at Miinster, registered 

 the paths of 602 shooting stars, and at Gaesdonck on the 

 same night, 563 were recorded between gh. 17m. and 

 I2h. 9m. It may be mentioned as a curious anomaly, 

 showing how much " personal equation " may have to do 

 with the estimation of meteor magnitudes, that at the 

 two stations referred to, the meteors were classified z.% 

 follows : — 



Number Total 



ist mag. 2nd mag. 3-6 mag. with „., ,„ ., 



streaks. meteors. 



Miinster ... 224 ... 226 .. 151 ... 300 ... 601 

 Gaesdonck ... 37 ... 84 ... 442 ... 158 ... 563 



The Miinster observers evidently overrated the magni- 

 tudes to an enormous degree. 



The display of 1871, though less decided than in 1863, 

 was still a very rich return of these meteors. On August 

 10 in that year, Signor Bassani, at Cosenza, in Italy, 

 assisted by Signor Scrivani, counted 674 meteors from 

 9h. to i6h., and at Boston, Mass., Messrs. Sawyer and 

 Stephens, watching the sky from loh. to I5h. on the 

 same night, recorded 567 meteors. Since that year the 

 displays have not been of special brilliancy, though on 

 August 10, 1874, 281 meteors Avere counted at Bristol by 

 the writer in a watch of four hours, from 10.45, t° i4-45> 

 and on August 10, 1877, 354 meteors were seen in the 

 five hours, from 9.30 to 14.30, giving an hourly number 

 (for one observer) in both years of about seventy. 



Dr. Phipson suggested^ it was to be inferred from the 

 observations that a maximum occurred at intervals of 

 eight years. There had been considerable showers in 

 1839, 1847, and 1863, and he pointed out that a similar 

 manifestation was due in 1871. In that year we had, as 

 already described, an unusually numerous return of these 

 meteors, and if the suspected periodicity held good, there 

 would be another rich shower in 1 879. Perhaps on that 

 account the Perseids of the present year were anticipated 

 with a little more than ordin.iry interest, but the night of 

 August 10 was generally overcast in England (though at 

 several stations a few meteors were discerned through 

 breaks in the clouds), and thus the chief display has 

 escaped us, though we may yet receive favourable reports 



' See his " Meteors, AeroKlef , and Falling Stars," p. 159. 



