202 



KNOWLEDGE 



[November, 1903. 



way. It will be necess.iry to have in addition to the source of 

 illuminatiou a bull'.s-ev-e condenser. 



Remembering that the images do not come into view in the 

 same focal plane as the cornea itself, but in a higher one, the 

 same as when viewing the images, the subject is focussed on 

 the ground-glass screen of the camera, and the negative taken. 

 Heads and busts of people seem to form the most suitable and 

 popular objects with which to experiment. 



Practicai, Scueme.— Through the kindness of Mr. A. H. 

 Williams, of Hythe, we are able to ofEer a quantity of zoophyte 

 material for distribution. Any readers desiring to avail them- 

 selves of this are invited to send a stamped addressed envelope, 

 together with the coupon which will be found in the advertise- 

 ment pages. I-.M 



NOTES AND QUERIES. 



A. Merjxon. — I am not quite sure from your letter whether 

 you require a book on biology or on natural history ; but if it 

 is to have special reference to the numerous subjects which are 

 available for microscopical examination, you cannot do better 

 than procure " The Microscope and its Revelations," by 

 Carpenter, edited by Dr. Dallinger, and published by Churchill. 

 For Protozoa only you would probably find the work entitled 

 " The Foraminifera : An Introduction to the Study of Protozoa," 

 by F. Chapman, very helpful. 



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. 



Boreellt's Comet (1903 c).— This comet is noiv visible only in 

 the southern hemisphere as an exceedingly faint object. Some 

 interesting reports of observations are given in Popular Astronomy. 

 Mr. C. D. Perrine at the Lick Observatory writes that, with the 

 Crossley reflector, a spectrum was obtained with a small slit-spectro- 

 graph on July 15, with an exposure of four hours. Fire bands were 

 shown similar to those pliotograplied by Campbell in Rordame's comet 

 of 1893, and Gale's comet of 1894. The brighter of tlie bands show 

 evidence of composite character, altliough they are not resolved. Very 

 little continuous spectrum is exhibited. Mr. hf. D. Curtis observed 

 the spectrum with the 36-inch refractor on July 14 and 15, and says 

 that visually it showed a relatively strong continuous sjiectrum and 

 three characteristic bands. Of these, that at \ 4700 seemed brightest. 

 An attempt was made to photograpli the spectrum, but the intrinsic 

 brightness of the comet was too small. The comet itself was photo- 

 graphed on several occasions, and two tails appear on all the plates 

 except the last (July 141. On June 30 the primary straight tail 

 extended over 5 degrees, while the secondary curved tail had a length 

 of li degiees. On July 14 there was one straight narrow tail 8i 

 degrees long. 



From observations of the same comet made by M. Deslandrea at 

 the Meudon Observatory, and reported in the Comp/es Sendus, it 

 appears that tlie spectrum was found of the characteristic hydro- 

 carbon type, but in the region of the nucleus some additional bands 

 were faintly exhibited. M. Deslandres tliinis that the temperature 

 of the comet is sufficiently high to bring about incandescence, and 

 concludes that the spectrographic method is capable of increasing 

 our knowledge of cometary physics by defining the structiu-al motions 

 of comets. 



BaooKs's Comet (1889 T.— 1896 VI.).— Too faint lo be observed 

 in small telescopes, this periodical comet is now situated in the 

 eastern region of Capricornus, near «, and moving very slowly east- 

 wards in a direction away from the earth, though its perihelion 

 passage will not occur until December 11. 



GiACOBisi's Comet (1896 V.). — Astronomers have been sweeping 

 for this object, but apparently without success. It passed its perihelion 

 in June. On October 28 its position is R.A. 3h. 55m , Dec. -I- 8° 7', 

 or about 10 degrees S. VV. of the Hyades in Taurus, and the motion is 

 extremely slow to S.W. 



MErEOEio Showers rx September. — Not many meteors were 

 observed in September this year, but the month is usuallv a 

 productive one both of fireballs and ordinary shooting stars. In the 

 morning hours at this iieriod, swift, streaking meteors are sometimes 

 very numerous, and their discursive flights afford evidence of an 

 abundance of radiants distributed over the eastern quarter of the 

 heavens. As a means of reference during future observations the 

 following list has been compiled of the positions of the principal 

 showers. These include the swifter class of meteors only ; there are 



a considerable number of streams of slow meteors visible at the same 

 season, but these are chiefly placed in the southern sky, and generally 

 best observed in the evening hours : — 



Kadiaxts OP Swift, Streaking Metbobs, Septembeb 10-27. 



48 -h 44 



55 + 71 



56 - 12 



57 -I- 9 



60 + 49 



61 + 30 

 63J + 22i 

 71+3 



74 + 42 



75 ■*- 15 



77 + 32 



78 + 57 

 80 + 24 



86 + 34 



87 + 42 



87 + 57 



88 + 19 

 98 + 43 



100 + 13 



105 + 51 



105 + 69 



1U7 + 12 



111 + 24 



115 -H 83 



118 + 31 



123 + HI 



127 ■^ .58 



130 + 46 



134 + 37 



156 + 41 



The most active of these appears to be the one at 61° + 33°, near 

 I Persei. 



The Leoxids. — There will be little appreciable interference from 

 moonlight in 1903, and the shower should be carefully looked for on 

 the mornings of November 14 to 17. The conditions scarcely justify 

 the anticipation of a plentiful display, but it may be confidently stated 

 that the Leonids will return, if not in rich numbers, at least in 

 sufficient strength to form a definite shower and to enable their point 

 of radiation to be redetermined. That the stream is one of annual 

 occurrence, like the August Perseids, is certain, though there is a 

 marked distinction between the two, the Leonids being very thickly 

 clustered near the parent comet and scantily dispersed over other 

 sections of the ellipse, wliereas the Perseids form a pretty rich and 

 evenly strewn orbit capable of yielding a moderately strong shower 

 every year. 



Large Meteors. — Mr. A. C. Sykes, while at Wadbury, near Frome, 

 Somerset, on September 12, 9h. 23m., saw a meteor brighter than 

 •Tupiter pass from a considerable distance above that planet to above 

 and beyond Altair, the direction being from Andromeda. It 

 descended at an angle of about 15° and left a luminous streak for 

 3 seconds. Probably the meteor was one of the e Perseids. On 

 September 23, at 12h. 30m., the writer, at Bristol, recorded a bright 

 flashing meteor, whicb must have exceeded Venus, with a path from 

 78° + 68° to 127" -r 77°, and a radiant at 63° + 23°. Its uneven 

 streak remained risible about 15 seconds. It is to be hoped that this 

 fine specimen of the September Taurids has been observed at other 

 stations. The particular shower from near c Tauri to which it 

 belonged is a tolerably active one during the third week in September. 

 On October 3 two meteors rather brighter than Sirius were observed 

 at Cardiff at lOh. 5m. and lOli. 12m. respectively. The first moved 

 from Perseus towards the Pleiades, an! vanished about 3 degrees 

 west of that cluster. The second travelled more slowly, and pursued 

 a lonzer course, from Polaris to Capella. On October 13, at 9h. 20m. 

 G.M.T., Mr. W. H. S. Monek, of Dublin, saw a meteor equaUing 

 Jupiter in apparent brightness. It passed slowly from a little below 

 the double star-cluster in Perseus to between Capella and Ursa 

 Major, and finally disappeared in that part of the Lynx bordering 

 L"rsa Major. 



Detonating Fieebail. — On Saturday afternoon, October 3, a 

 large aerohte is reported to have fallen near Tain, in the north of 

 Scotland. It appeared as a ball of fire, which burst immediately 

 over the town, and gave a thunder-like report audible over a wide 

 extent of the siu'rounding country. Doors and windows rattled in 

 the villages of Eastern Ross, and the inhabitants were greatly 

 alarmed. A telegram fi'om Rogart, Sutherland, reports a shock of 

 earthquake as having occurred at the same time, but this was 

 eertainlv due to the detonation and vibration of the fireball. 



THE FACE OF THE SKY FOR NOVEMBER. 



By W. Shackleton, f.r.a.s. 



The Sun. — On the 1st the sun rises at 6.53 and sets at 

 4.34; on the 30th he rises at 7.42 and sets at 3. -54. 



The solar disc is now rarely free from spots and faculae; 

 at the time of writing there is a spot-group of considerable 

 size visible. 



The Moon: — 



