106 



KNOWLEDGE, 



[July, 1903. 



He therefore uses no cements, but after allowing a fortnight 

 for drying, he covers the remainder of the sliji with paper, 

 being cartful to avoid any pressure when applying it. By this 

 means he has been able to secure mounts which have every 

 promise of permanence, and much trouble in the preparation is 

 obviated. 



NOTES AND QUERIES. 



W. n. ToiDit/. — Mr. J. T. Neeve suggests that you soak the 

 Algae in methylated spirit for some little time to make them 

 transparent, and, in order that you may experiment, I have sent 

 you some fronds that I have received from him, but is it really 

 necessary for such delicate specimens as DelUxeria to be treated 

 in this way at all ? Are they not sufficiently transparent for 

 lantern projection without this ? 



E. W. Najjper. — The following is the formula for Deane's 

 medium : — 



Gelatine ... ... ... 1 oz. 



Honey ... ... ... 6 ozs. 



Water ... ... ... .5 ozs. 



Rectified spirit ... ... i oz. 



Creosote ... ... ... 6 drops. 



Soak the gelatine in the water until soft, add the honey, then 

 boil the mixture. When it has cooled somewhat, the creosote 

 mixed with the spirit is added. Lastly, filter through fine 

 flannel. The medium is used warm. 



A. II. Brett. — The specimen you send is an egg cluster of 

 whelk. 



Communications and enquiries on Microscopical matters are 

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

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



NOTES ON COMETS AND METEORS. 



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



Fatb's Comet. — This interesting periodical comet has probably 

 returned to perihelion this year after a much shorter interval than 

 usual, having experienced considerable perturbation from Jupiter. Xo 

 information of its recent redetection lias, honever, come to hand, and 

 the probabilities are that it will escape notice owing to its unfavourable 

 position. This comet has been observed during each of the seven 

 returns which it has made since 1S43, and its average period has been 

 2735 days or 7-488 years. Tlie following is a list of the dates of its 

 perihelia and of its periods of revolution : — 



Perihelion Passage. 



1843 October 17 

 1851 April 3 

 1858 September 12 

 186fi Februarv 13 

 1873 July 18" 

 1881 January 22 

 1888 August 9 

 1896 March 19 

 1903 June 3 



;volntion. J^'^^ °^ 



Days. Discovery. 



1843 Nov. 22 ... Fave 



2725 ... 1850 Nov. 28 ... Challis 



2719 ... 1858 Sep. 8 ... Bruhns 



2711 ... 1865 Aug. 22 ... 'J hiele 



2712 ... 1873 Sep 3 ... Stephan 

 2745 ... 1S80 Aug 25 ... Tempel 

 275f? ... 1880 Aug. 19 ... Perrotin 

 2779 ... 1S95 Sep. 26 ... Javelle 

 2631 (Predicted) 



Dr. Elis Stromgren, of Kiel, gives the following ephemeris in 

 Ast. Xach.,3SbS: — 



Date 



1903. 



June 26'5 



Jidv 18-5 



Aug. 95 



., 31-5 



When last seen on 1896, January 15, the light of tlie comet was 

 = 061, so it should be rather fainter than that during the present 

 summer, when it will be not far west of the sun and moving from the 

 head of Taurus, through Gemini, into Cancer. 



New Comet.— On April 17, llr. J. Grigg, of Thames, Ne<v 

 Zealand, discovered a small comet in the S. E. region of Cetus. It 

 was soon found that the object had passed its perihelion on March 25 

 and was recedmg both from the sun and earth. It was observed by 

 Mr. John Tebbutt at Windsor, N S.W., on April 26, but its position 

 since its discovery has been too far south for English observers to 

 ubtaia a view of it. 



Apbil Meteors. — Prof. A. S. Herschel, at Slough, secured a 

 valuable series of observations between April 16 and 23, watching for 

 21 hrs. 20 rains., in the aggregate and recording 85 meteors, of which 

 23 were Lyrids. Meteors were generallv very scarce. 8 Lyrids were 

 seen in 3| hrs. on April 21. and 11 in 5 "hrs. on April 22. The 

 radiant was at 269° + 34", and about 4 degrees in diameter. 



Mr. A. King, of Leicester, watched for meteors on nme nights, from 

 April 15 to 21, the weather being extremely favourable. In 19^ hrs. 

 observation he registered 80 meteors, including 25 Lyrids. The latter 

 were nearly all .seen on April 21 and 22, and the maximum occurred 

 on the 2 1st, but it was rather a feeble display. 



Several bright meteors were also seen from a radiant at about 

 216" — 26°, which represents a return of a well-defined shower 

 observed by Prof. Herschel and others, from the point 218° - 31°, 

 during the April epoch of 1900. 



3Iat Aquabids. — A rich display of these meteors was observed by 

 Mr. Gr. M. Knight, of London, W.C, on the first four mornings of 

 Mav last. 25 Aquarids were recorded, of which 18 were equal to 

 or exceeded stars of the 1st mag. in brilliancy. They had long 

 flights, slow motions, were generally of an orange colour, and left fine 

 trails. The mean place of the radiant was at 330" ± 0", but Mr. Knight 

 thought that the point exhibited a decided N.E. movement during 

 the four nights of observation, the centre, before sunrise on May 1, 

 being at 327° — 3", while on May 4 it appeared to be at 332" + 3°. 



Mat Meteoes. — A period of very clear summer-like weather 

 occurred between May 18 and 31, and observations were obtained by 

 the writer, at Bristol, on 11 nights. Meteors were, however, visible 

 in scantv numbers, only 75 being noted in 18^ hours of watching. 

 There were feeble radiants at 194" + 58°, 248" -i- 27°, 263° -I- 37", 

 273" 4- 22", 278° + 31", 311° + 80", 330" -i- 58", and 331° + 72". 

 Perhaps the most interesting object recorded was a small fireball, 

 which appeared on May 26, 13h. 48m., falling very slowly in 

 4 seconds, from 143° + 71° to 98° + 66i". A stream of yellow sparks 

 followed in the immediate wake of the nucleus as it sailed leisurely 

 down the northern sky. 



DocBLT-OBSEEVED Meteoh. — Prof. Herschel. of Slough, recorded 

 a meteor, equal in brightness to Vega, on May 26, llh. 47m. It 

 traversed a path from 225° -i- 73^° to 172° + 56° in 1'2 seconds, and 

 left a rather bright, white streak. The same object was observed by 

 the writer at Bristol, moving ratlier slowly from 315° -I- 37° to 

 309° + 61" in 2 seconds, and leaving a bright streak along three- 

 fourths of its track. The meteor was evidently an early Pegasid 

 directed from 321° + 11°. Its luminous flight began at a height of 

 64 miles over Dunstable, and ended near Burford, Gloucestershire, 

 extending over 51 miles at a velocity of 31 miles per second. 



L-\rge Meteors. — On May 8th, 5h SOm p.m.. Miss Westmacott, 

 at Haslemere, Surrey, observed what appeared like a silver meteor 

 travelling with great speed from E. to W., at an angle of about 

 35 degrees On Sunday. May 24th, two brigiit meteors were noticed 

 by the Rev. \\'. F. A. Ellison, of Enniseorthy. The first appeared at 

 lOh. 20ni G.M.T., and was about equal to Venus. It passed slowly 

 from 180" — 8° to 133° + 12 j° in 6 seconds. Colour white or yellowish. 

 It left a long faint train. The second meteor appeared at lOh. 59m. 

 G.M.T., and was of the brightness of Mars. It travelled from 

 172' -I- 51° to 267° -I- 73° in 3 seconds, and left a broad and strong 

 nebulous train. The radiants of these meteors were probably at 

 252" — 24" and 147" — 12°, but no other observations have come to 

 hand. 



THE FACE OF THE SKY FOR JULY. 



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



The Sun. — On the 1st the sun rises at 3.48 and sets at 

 8.18 ; on the olst he rises at 4.22 and sets at 7.50. 



The earth is at its greatest distance from the sun on the 

 3rd, when the sun is in apogee, and then has its le.ist 

 apparent diameter of 31' 30''"6. 



Small groups of suuspots have been frecjuent of late. 



The Moon: — 



Julv 



Phases. 

 ]) First Quarter 

 O Full Moon 

 ([ Last Quarter 

 # New Moon 

 ]) First Quarter 



9 2 P.M. 



5 43 P.M. 



7 24 P.M. 



12 46 P.M. 



7 15 a.m. 



