142 



KNOWLEDGE. 



[June, 1901. 



they will kindly accompany their application with stamps to 

 cover cost of postage on the material. 



Red Rain.— In connection with the recent falls of so-called 

 red rain, I have received letters from two correspondents, one 

 of whom enclosed a small quantity of material distributed by 

 Captain C. J. Gray, which had been collected by him after a 

 heavy fall of rain on December ^Sth, 1896, in Melbourne, 

 Australia. I have had the material mounted, but the quantity 

 which I received did not contain the variety of matter that some 

 other correspondents have noted. Observed by transmitted 

 light, there were few characteristic particles, but with the aid of 

 a°polariscope I was able to detect some small crystalline 

 fragments of the nature of quartz, etc. It seems more than 

 pro°bable that the phenomenon arose in consequence of one of 

 those heavy winds which have been known to carry dust from 

 the Sahara as great a distance as 500 miles, and which in this 

 case may have passed over some sandy tract in a like manner. 

 The material has all the api)earance of such dust. There are 

 some interesting references to falls of red rain in P. H. Gosse's 

 " Romance of Xatural History," but none of them are of the 

 .same nature as the dust at present under consideration. 



Dr. n. M. Whclphij.—l have to give you my best thanks 

 for so kindly sending the numerous interesting papers in 

 connection with chemical and pharmaceutical subjects, and 

 especially for the engraving of the Pre-Columbian Indian Flint 

 Implement. This is certainly a most interesting and peifect 

 specimen. 



Comnuui lea 'ions and enquiries on Microscopical matters are 

 cordiaUy invited, and should be addressed to M. I. Cross, 

 KNOwr.EDGE Office, 326, IIi(/h Holborn, W.C. 



NOTES ON COMETS AND METEORS. 



By W. F. Denning, f.r.a.s. 



T.ARGE Comets.— Pnif. A. Kn-ulz, nlilnr ol' (lie Axtronomisi-Iii- 

 NachricMen, has recently issued a work giving the results of his 

 eumimtiitions and eouipansous of (lie orl)it3 of the comets of 1680, 

 184H I., 1880 I., 18S2 11.. 1887 I., ete. These several objects offered 

 some s'uggestive resembhuices hotli as regards their physical features 

 and their orbital elements. But they appear to have l)eeu, iudividuidly, 

 rtistinet bodies revolving in ellipses of long period. They exhibited, 

 liowever, a sufficient all-rouud similarity to warrant the inference that 

 thev originated from the same source, and may ha\ e )irimarily formed 

 an immense eomet, which meountered d^turbances of sueh force as 

 to diseoiuiect its uiatei-ial>. and distribute f lu-ui into a family of large 

 comets of various periods, and with perilielia remarkably elose to the 

 8UD. Tlie time of revolution of the eomet of 1680 was about 8449 

 years, of 1843 I. 511 years, of 1880 I. and 1882 II. 800 years; but 

 in llic ease of 1887 I. the elements are extremely uncertain, the eomet 

 being only observed on a few nights iu the Southern Hemisphere. 

 Certain o'tlier bright comets, iu aclrlition to those speeified, exhibited 

 features of orbit and aspect whiih indieate their ])ossible identity 

 with the class alluded to, but the observations were not very accurate, 

 and reliable conclusions cannot be deduced from them. 



Xew Comet. — On April 2:irtl, a telegraphic dispatch from Sydney 

 reported that a brilliant comet was seen in Australia, and the same 

 objeet was observed at Capetown during the two hours preceding 

 suiirise. It had a triple tail ten degrees in length. The astronomers 

 at Yerkes's Observatory are said to have picked up tlie eomet on 

 the morning of April 27tli, uud it was seen by several observers at 

 Eastbourne, according to the newspapers, on "May 1st, at 3 a.m., but 

 as the comet did not rise in England until after 6 a.m. on that mornini; 

 the observers must have been deluded by some false appearance. Tlie 

 perihelion passage occurred on .April 54th. at a distance of about 23 

 millions of miles from the -un. The following extracts from an 

 epheraeris by Kreutz, Ast. Nach., 3712, will show that during Ma_\ 

 the comet rapidly receded from the earth, and became so faint as to 

 be practically invisible in the strong twilight of the season :— 



Distance from 

 Date. R.A. Dee. Bi-ightness. Earth in Mil. 



H. M. s. * ' lions of Miles. 



Mav 4 ... 3 57 49-0 144 . . 037 ... 82 



"14 . . 5 31 49 + 3 2.5-9 ... ()9 ,.. 107 



" 24 ... 6 20 18-1-6 21-2 ... 0(« ... 138 



On June 1st, the comet will be about one-lnmdredtb part as bright as 

 it was when near perihelion, and will be situated in about 100'' + 8°, 

 so that this object which afforded such a conspicuous aspect in the 



southern hemisphere, has virtually come and gone (like the tine comets 

 of 1880, February, and 1887, January) under conditions which 

 prevented a single glimpse being obtained by northern observers. 



The Aphil Meteors. — The weather generally was very favour- 

 able for the observation of these objects, and moonlight offered no 

 interference until the later stages of the display. Usually meteors are 

 very scarce in ,\pril, and this year proved no exception to I he rule. 

 At Bristol the writer obtained observations on April 13th, 17th, 18th, 

 19th. 20th, 2Ist. 23rd and 2ttli, and during watches amounting in 

 the aggregate lo 19 hours saw 122 meteors. The first byrid was 

 I'ccorded on April 18th, at 13h, 19m., and it was fortunately also 

 mapped by Prof. A. S. -Hcrschel at Slough. It descended :it a normal 

 elevation above the earth's surface, and its radiant at 266° + 33° 

 proves that this centre, like that of the Perseids, moves eastwards 

 during the time of its visibility. On April 20th, during a watch of 

 five hours the writer noticed 29 meteors, but there was not a single 

 Lyrid amongst them ! Yet, on April 21st, during a watch of 3^ hours 

 25 Lyrids were seen, and 27 other meteors. It was evident that on 

 this night the shower reached a definite maximum. Allowing for 

 time spent in registering the paths, etc,, the horary number of Lyrids 

 for one observer was about eleven. The radiant point on April 21st 

 was at 270' + 33", showing an ea.sferly drift of i degrees of R.A. 

 (equal 3 degrees of space) during the three nights. The following 

 ephemeris will probably re|n'e.~cnt the |)lare of the radiant pretty 

 aecurafclj- on eleven nights, and it will be importaut to test it by 

 future <»bserv;ition8, but the shower is exeeedingly feeble at its earlier 

 and later stages, so it will be advisable to incorporate the paths i>f 

 different observers : — 



a S ' a 5 



Date. o o Date. o o 



April 15 ... 263^ + 33 Aprd 21 ... 271 -t- .33 



16 ... 264J + .33 „ 22 ... 272^ + 33 



„ 17 ... 266 + 33 „ 23 ... 273i + 33 



„ 18 ... 267i + 33 „ 24 ... 2745 -H 33 



19 ... 2G8i -h 33 ,, 25 ... 276 + 33 



„ 20 ... 2692 -f 33 



1900 not being a leap year the effect will be tlmt for some lime iu 

 tlie future th<' maximum will occur one day later than formerly. 

 Thus the tjuadrautids will occur on January 3rd instead of 

 January 2nd, the L\ rids on April 21st instead of April 20th, and the 

 Perseids on .\ugust 11th instead of August 10th. The recent display 

 of Lji'ids was successfully observed by several observers iu 

 various parts of Knglaud. Prof. Herschel at slough made a 

 considei'alde number of accurate observations, and remarked the 

 singular scarcity of nuHeoi's except on the special night, April 21st. 

 He then saw 18 Lyrids in about three hours, nearly all 1st or 2nd 

 magnitudes. Mr. C. L. Brook, of Meltham, near Huddersfield, 

 counted between 40 or 50 meteors on April 21, including a number 

 of Lyrids. One of tlie most brilliant of these appeared at loh. 8m.. 

 and was also recorded by Mr. T. H. Astbury, at Wallingfoi'd, and the 

 writer at Bristol. It fell from a height of 70 to 51 miles over the 

 Midlands. But the most interesting meteor observed at more than 

 one station during the recent display was that of a bright Cassiopeid 

 which came into view at llh. 2im. on April 21. Its radiant, from 

 observations at Meltham and Bristol, was at 21 -t- 59 ' near J Cassiopeia;, 

 and it descended fi'om 66 to 44 miles in a path of ."io miles, 

 directed from north to south over the counties of Carnarvon, 

 MeriiMietli, and Cardigan, in Wales. Its velocity was 14 miles per 

 second. It is remarkable that slow-moving fireballs often take their 

 flights from this radiant near J Cassiopeia" in the spring monlhs of 

 Ajiril and May, though ordinary shooting stars come rarely fi-om tliat 

 focus in tlie vernal season. The fireball of 1891. ,\pril 2, had a 

 radiant of 29' + 55° ; tliat of 1876, April 9. at 17"-^ 57° ; that of 1874. 

 April 10, at 19° -I- 57 ; thatof I89.3,April 15, at 1.5° -h 59'; and that of 

 1S77, May 30, at 20+58°. The various catalogues of meteoric 

 observers contain other instances of brilliant slow-moving .4pril 

 meteors from the same radiant in Cassiopeia. 



THE FACE OF THE SKY FOR JUNE. 



By A. Fowler, f.r.a.s. 



The Son. — On the 1st the sun rises at 3..52, and 

 sets at 8.4 ; on the 30tli he rises at 3.49, and sets 

 at 8.18. He enters Cancer, and Summer commenoes on 

 the 22nd at 3 a.m. Few sunspots are to be expected. 



The Moon. — The moon will be full on the 2nd at 

 9.53 A.M., will enter last quarter on the 9th at 10.0 p.m., 

 will 1)6 new on the Itith at 1.33 p.m., and will enter first 



