238 



KNOWLEDGE. 



[OOTOBBB, 1902. 



These wore rospoiuled to by the other insects and tho moment 

 the impriaoneti one wiis assured that it had attracted the 

 attention of the new comers, it ceased to emit light. 



Li. Damaiit, — The study of marine life covers such a very 

 broad area that you would almost need a library for the purpose 

 of identification of specimens. Probably one of the most 

 comprehensive books you can have would be the Jticrographic 

 Dictionary, costing i'J 12s. Gd., Carpenter's " Micro.scope and 

 its Revelations," edited by Dr. Dallinger, ought also to be of 

 material assistance to you ; the cost of this is 28s. Probably 

 your best plan would lie to get into communication with one of 

 the Marino Hiologioal Stations, from whom you could no doubt 

 obtain particulars of the most suitable apparatus and processes. 

 The two best microscopical societies are The Hoyal Micro- 

 scopical Society and The Quekott Club ; both of them meet 

 at "20, Hanover Square, London, W. You would find their 

 journals helpful. The 2" objective would be a useful addition 

 to your equipment. I am very much obliged for your offer to 

 collect material. 



A Igic. — A correspondent has pointed out a slip which occurred 

 in the Algie article last month, on page 212, column 2, para- 

 graph 4. H"or " chloride of lime " read " carbonate of lime.' 

 Readers might also note that if tufts of seaweed, which are not 

 in a growing conditioij, are required to be kept for any length 

 of time, they must be preserved in strong salt water or 

 glycerine — they will not keep long in sea-water. 



Communications and enquiries on Microscopical matters are 

 cordially invited, and should be addressed to M. I. CROSS, 

 Knowledge Office, 326, High Holborn, W.C. 



NOTES ON COMETS AND METEORS. 



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



New Comkt. — Mr. C. D. Perrine, of the Lick Observatory, Mount 

 Hamilton, discovered a new comet on the morning of September 1st, 

 about 6° S.S.E. of the variable star Algol. From computations which 

 have been made it seems the perihelion passage will take place on 

 November 23rd, and that the comet is approaching us and rapidly 

 becoming brighter. Its position is exceedingly favoui'able for observation 

 in the northern hemisphere. At the beginning of October the comet 

 will be in or near the head of Cepheus, and may be reatldj' found, as 

 it will be tolerably conspicuous and probably visible to the naked eye. 

 During the month named its motion will become increasingly rapid, 

 and in a direction approximately towards the sun's place. 



The following ephemeris for Greenwich midnight has been 

 computed by Dr. D. Smart, of London, from Stromgen's parabolic 

 elements : — 



Date E.A. DecUnatiou. Bri^btuess. 



1902. H. M. s. o ■ Sep. 1 = 1 



September 30 ... 23 32 12 +57 1 160 



October 4 ... 21 22 32 52 50 228 



„ 8 ... 19 42 4 40 14 25-7 



12 ... 18 44 24 26 4 232 



10 ... 18 10 50 14 48 191 



20 ... 17 49 36 6 43 15-7 



21 ... :7 34 32 -H 55 13-6 

 28 ... 17 22 48 - 3 24 12 3 



Tempki.-Swift's Comkt (1869 III.). — We may shortly expect to 

 hear of the re-discovery of this well-known periodical comet. Its 

 time of revolution is as nearly as possible 5^ years, for its first 

 observed perihelion occurred on 186tl, November 18, while the last 

 took place on 1891, November 14, the comet having, in the interval 

 of 22 years, completed four circuits of its orbit. The position of its 

 path and length of its period are such that the object can only be 

 observed at alternate returns to perihelion, for at its approaches 

 to the sun in 1875, 1886, and 1897, the comet was placed on the 

 opposite side of the sun to the earth, and therefore rendered invisible 

 by two causes, viz., its great distance and the interference of solar 

 light. It owes its first discovery to Tempel, at Floronec, on 1869, 

 November 27, when it was situated near the star a Pegasi, and 

 appeared as a faint object about 2^ minutes of arc in diameter. It 

 was rc-detected by Lewis Swift at Rochester, New York, on 1H80, 

 October 10, and after a few observations had been obtained, Chandler 

 and Schulhof pointed out the similarity of its elements with that of 

 Tempel's comet of 186.), and inferred a period of 5.J years. This 

 was verified by the reappearance of the comet in 1891. and it will 

 doubtless be seen again during the ensuing autumn. Visible only as 

 a faint telescopic object, it canno* be said to possess any specially 



attractive features for the observer, but astronomers regard it aa a 

 very interesting example of the Jovian family of comets, the number 

 of wliich has been greatly increased in recent years, owing to the 

 assiduity and success with which comet-seekers have pursued their 

 labours. 



FiRKDALL OF ArorsT 21, 14h. — Astronomical observers appear 

 to have been caught napping on the early morning of Friday, August 

 22, when one of the most brilliant and remarkable meteors of 

 recent years made its apparition. Apart from its unusual size, the 

 exceptional features about it were its extreme slowness of motion, 

 its great length of path, and the dense tail of sparks which it left 

 behind. About twenty descriptions have come to hand from ca«ual 

 observers, and it may be interesting to quote some of the details: — 



Mr. .1. E. Sanders, Plymouth, was on board a ship abreast of Mewstone 

 when there suddenly appeared a very bright light with a lariie head, 

 which travelled at a great pace. It lit uji sea and land for miles 

 around as if it were day. Rising in the W.S.W., it travelled in an 

 horizontal position to the E.N.E., passing 10 or 12 degrees below the 

 moon, and leaving a long curved tail in its wake. Its duration 

 was about 2 minutes. Mr. Sanders says that though he has been 33 

 years at sea, and travelled in all parts of the world, he has never 

 seen any celestial sight comparable with that of the fireball. 



Mr. J. Durston, Plymouth, was on the Hoe, and says the meteoi- 

 was of great length, large head with slightly curved tail, and mag- 

 nificent brilliance. It sped across the sky at a terrific rate percepiibly 

 (to all appearance) dividing the lower strata of cloud. It was 

 travelling from W.S.W. to E.N.E., and apparently broke up at the 

 end, after being visible 30 seconds. First seen in azimuth, S. 71° W., 

 and disappeared in azimuth, E. 5° S. 



At 8t. Agnes, Cornwall, a spectator says it was first noted away in 

 the south as a star of great brilliancy, moving very slowly round to the 

 N.E., and disappearing at the horizon without having spent itself. 

 It had no tail, and it kept at the same apparent altitude throughout, 

 though it travelled a very long distance. The St. Agnes observer 

 adds tliat tliis is doubtless " the same object as seen by Mr. Durston at 

 Plymouth, but with this difference, that no tail was visible at St. 

 Agnes, and that its speed was excessively slow." 



Dr. Wm. Whitworth, of St. Agnes, describes it as appearing in the 

 south and disappearing in the N.E., after traversing a most unusual 

 length of sky. The speed was comparatively slow ; the ball of fire 

 seemed to glide rather than shoot through the air. Altitude 20" or 

 25", duration 40 seconds. 



" R. J. W. M.", writing from Sandquay, Dartmouth, says the meteor 

 appeared at 2h. 5m. a.m., and travelled very steadUy across the sky 

 from W. to E. It had the aspect of a perfectly round blue ball 

 without a tail. 



R. R., Devonport, was on board a pilot boat close to the Eddy stone 

 Lighthouse when he suddenly saw an object as bright as the moon, 

 and with an enormous tail of fire, taking an horizontal flight right 

 across the heavens, and increasing in brilliancy in its travel until u«ar 

 the E. horizon, when it died out. Duration 30 seconds. 



Polperro fishermen observed the meteor. It was '' awfully grand 

 and visible for a lona time," passing straight across the sky from 

 S. of the Dodman to N. of Rame Head, shooting out a tremendous 

 number of stars along its course. " Sailors who have sailed in many 

 seas aver they never saw anything like it before." 



A Southampton correspondent alludes to the meteor as appearing 

 over the River Test side of Southampton Water, and travelling with 

 phenomenal slowness from W. to E. It looked like a great ball of 

 fire, and left a very long trail of electric blue sparks in its wake. 



Mr. W. H. Rowe, Leigh-on-Sea, gives the time as 14h. 2m., and 

 says he watched the fireball pass from S. 15° W. , altitude 8°, to S. 67° 

 E., altitude 8°. Diameter ith that of moon. Tail of brilliant 

 fragments, dying out 2° from the nucleus. Duration 30 to 35 

 seconds. 



Mr. C. F. Dowsett, Basingstoke, says the fireball passed in a straight 

 line from W. to E. Portions seemed to descend from it, while the 

 larger part continued its flight. It appeared travelling at the same 

 rate as a train making 40 miles an hour. The position where he lost 

 sight of it was a little S. of E. 



Messrs. Blythe and Shorney, Tamworth, near Birmingham, 

 describe the meteor as leaving few sparks behind it. It moved 

 horizontally and very slowly towards the E. 



At Sidcu]), Eltham, it was very brilliant; ti-avelled quite slowly in 

 au horizontal path. Duration probably half a minute. 



At London it passed from west to east across the sky, and its 

 direction was parallel with the horizon. Its duration of flight was 

 half a minute, and it developed a tail like that of a comet. Three 

 Australian troopers, who were standing at Hyde Park Corner, say it 

 appeared to travel horizontally towards the S., that it was visible about 

 3 minutes, and had a long tail. 



From these and a few other accounts, which are not, however, very 

 definite and satisfactory, the following approximate real path has 

 been derived : — 



