94 



KNOWLEDGE. 



[April 1, 1899. 



Tempel's Comet (18fi7 II.). — This comet was seen at its 

 returns in 1873 and 1879, but escaped notice in 1885 and 1892. 

 Gautier pointed out, some time ago, that under the powerful 

 influence of Ju))iter's attraction the time of revohition had been j 

 lengthened, and announced that a perihelion passage of the 

 comet would occur in September, 1898. It evaded detection, 

 however, though Perrine, at the Lick Observatory, made a 

 careful search for it with the 36-inoh refractor and other 

 instruments. 



Meteors op March 1-4. — Fireballs have often been observed 

 to be unusually numerous at this period, and it is probable that 

 a tolerably rich shower of slow bright meteors is occasionally, if 

 not annually visible, though it appears to have previously 

 escaped observation. From an investigation of the meteor- 

 paths registered at Bristol, on the first few nights of March, 

 the writer obtains radiants at 140" + 51", lC(3'" + .'i'', 176" + 9", a.nd 

 201°+ 07°, but the materials are not sufficiently numerous to 

 indicate satisfactorUy the jiositions of the best showers. A fine 

 meteor equal to Venus was seen by Mr. G. T. Davis, of Reading, 

 on March 1st, 1899, at about 8h. 45'm., moving from 187|" + 40i° 

 to 205° + 3,5° in 1| sees. The same object was observed by 

 Mr. T. H. Astbury, of Wallingford, traversing a ]iath from 

 168° + 33" to 191" + 25" in 4 sees. A comparison of the two 

 observations shows that the meteor jiassed over Essex, descending 

 from a height of fifty-eight to twenty-two miles along a path 

 of forty miles, with a velocity of about ten miles per second. 

 The radiant point was at 119° + ?>3°. Earlier on the same night, 

 at 7h. Im., Mr. Astbuiy had observed a meteor brighter than 

 Sirius, falling from 340" + 63° to 323° + 44° in 2^ sees., clearly 

 belonging to the same radiant in Gemini as that which furnished 

 the large meteor at 8h. 45m. 



The April Lyrids. — The Moon will reach her first quarter on 

 April 17th at lOh. 43m., and will therefore greatly interfere 

 with observations of this periodical shower in the present year. 

 Something of the early part of it may, however, possibly be 

 witnessed on the mornings of the 18th and 19th before sunrise. 

 It will also be worth while looking for it on the night following, 

 April 2(lth, for if the sky is very clear and the shower returns 

 with unusual intensity, it may be well seen in spite of the 

 presence of a gibbous moon. The shower is, however, often 

 very feeble and always brief in its visible duration. There is 

 one important point to settle in regard to its radiant at 270" + 32", 

 and that is whether it exhibits an easterly motion similarly to 

 the Perseids of August. There is very little doubt that the 

 radiant varies in its position from night to night, but the 

 thorough investigation of this feature must be relegated to one 

 of the April periods when moonlight is absent and when several 

 very clear nights occur successively. 



The May Aquarids. — These should be looked for before 

 sunrise, during the first week of that month. The radiant does 

 not rise until about Ih. 45m. A.jr., so that there is only a short 

 time, in the morning twihght, available for observation. It is 

 important that this shower should be well observed, as it has 

 rarely been seen, and presents some orbital resemblance to the 

 path of Halley's comet. 



[Adfhmdum, M<ircJi Ibth. — Since the above notes were written, 

 Prof. Lewis Swift, of California, U.S.A., discovered a comet on 

 March 4th, which he describes as just visible to the naked eye. 

 The comet has been too far south and too near the sun to be 

 favourably visible in England. At the beginning of April it 

 will be about twenty degrees east of the sun, and will be placed 

 to advantage in the mornings of May, when it will rise several 

 hours before the sun.] 



THE FACE OF THE SKY FOR APRIL. 



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



THE SUN.— On the 1st the Sun rises at 5.37, and 

 sets at 6.81 ; on the 30th he rises at 4.85, and 

 sets at 7.19. He will be at his mean distance 

 from the Earth on the Ist. Sunspots have not 

 been either conspicuous or numerous of late. 

 The Moon.— On the 3rd, at 11. 5G a.m., the Moon will 

 enter her last quarter; she will be new on the 10th, at 

 6.21 A.M.; will enter her first quarter on the 17th, at 

 10.43 P.M.; and will be full on the 25th, at 7.22 p.m. 

 The two most notable occultations of the present year 



will take place during this month. On the 15th, j«. Gemi- 

 norum, magnitude B'2, will be occulted. The star will 

 disappear at 11.26 p.m., at an angle of 65° from the north 

 point (26° from vertex), and will reappear at 12'8 at 319° 

 from north point (283° from vertex). The Moon will be 

 six days old, and the disappearance will take place at the 

 dark limb. On the 28th there will be an occultation of 

 S Ophiuchi, magnitude 3-4. The disappearance will take 

 place at 11.56 p.m., at 89° from north point (114° from 

 vertex), and the reappearance Ih. 6m. after midnight at 

 280° from north point (296° from vertex). The Moon 

 will be nineteen days old, so that the disappearance will 

 take place at the bright limb. 



The Planets. — Mercury is too near the Sun for obser- 

 vation in this month. He will be in inferior conjunction 

 on the 12th, and will afterwards be a morning star. 



Venus is a morning star, but is not well placed for 

 observation. Her path lies very near the ecliptic through 

 Aquarius and Pisces. On the 1st she rises at 4.28 a.m., a 

 little more than an hour before the Sun ; on the 30th at 

 3,37 A.M., about an hour before the Sun. At the middle 

 of the month, three-quarters of the disc will be illuminated, 

 and the apparent diameter will be 14-6". 



Mars is still well placed for observation, but his distance 

 from the earth is rapidly increasing, and his apparent 

 diameter diminishing. On the 1st he crosses the meridian 

 at 7.11 P.M., and sets at 3. .30 a.m.; on the 30th the 

 meridian passage is at 6.4 p.m., and he sets at 2 a.m. 

 The planet will be at aphelion on the 8th, and in eastern 

 quadrature on the 23rd. During the month the semi- 

 diameter of the planet diminishes from 8-4" to 6-8". The 

 path of the planet is from Gemini, being almost in line 

 with Castor and Pollux, at the beginning of the month, 

 into Cancer, reaching a point not far from the Praesepe 

 cluster about the end of the month. At the middle of the 

 month nine-tenths of the disc will be illuminated. 



Jupiter is very favourably situated for observation this 

 month, being in opposition on the 25th. On that date he 

 will have a south declination of 12°, and an apparent 

 polar diameter of 41-2". During the month he describes 

 a short westerly path in Libra, towards Spica Virginis. 

 On the 1st he will cross the meridian at 1.4 a.m., and on 

 the 30th, at 11.37 p.m., his altitude on the meridian being 

 about 26°. 



Saturn is not well placed for observation at convenient 

 hours during this month. On the 1st he rises about 

 12.50 A.M., crossing the meridian at 4.52 a.m., and on the 

 30th at 10.52, crossing the meridian at 2.55 a.m. He will 

 be stationary on the 2nd, at a point in the most southerly 

 part of Ophiuchus, and will afterwards traverse a short 

 westerly path. His south declination is 22°, so that even 

 when on the meridian his altitude in London will only be 

 about 16°. 



Uranus remains in the south-western part of Ophiuchus, 

 not far south-west of the star cu. He rises shortly before 

 midnight on the 1st, and soon after 9.30 on the 30th. 

 The planet has a south declination of 21^ degrees, and 

 will accordingly be very low in the sky. 



Neptune may still be observed up to midnight in the 

 early part of the month. He describes an easterly path, 

 nearly a degree north of ? Tauri, and preceding that star 

 by an amount which diminishes from 5m. 12s. to 2m. 2l3. 

 during the month. 



The Stars. — About 9 p.m. at the middle of the month, 

 Leo will be on the meridian ; Gemini in the south-west ; 

 Orion in the west ; Virgo in the south-east ; Hercules in 

 the north-east ; and Ursa Major almost overhead. 



Algol may be conveniently observed at minimum on the 

 18th, at 9.24 p.m. 



