JCLY, 1901.] 



KNOWLEDGE. 



1G7 



ci>uiet spiTf I'iso t» iimiiy I'lmfliitiiii; statoironts, Imt the hoiic was 

 iiuoiir!>!;i'<l that it noiihl (iri'si'iit a tinr appiiirami' in tin- I'vciiina sltv 

 ilurini; JIay. Maoy |>typli> «i'ii' diiia|>|u'intoil in faihng lo lalih a 

 ^liinpso of it, but it nia\ bo sonu- uonsohil ion tn Iheni to know that a 

 naktHl-ovi" ooniet boi-t>inos visible nearly every year, anil that they will 

 )ir>>bably not have lon^ to wait hefi're viewini; one of these wonderliil 

 anil mysterious visitors. 



DisTRiui'Tiox OF CoMETART Peiuiikli.\.— With refpxrd to the 

 eomets of short period, belonjjiiit; to the Jovian family, of whieh there 

 are now about 32 known with more or less eertainty and probably 

 quite distinct biMlies (though less than halt of them have been 

 observed at moiv than one return), it is remarkable that the lonsitiide 

 of perihelion falls between UDO — JUiO' and 0-60 in 20 eases, whereas 

 It is found between tJO'— ;!00 in only 12 eases. In other words, while 

 120 of longitude elaim 20 eoniet", 210 elaini only 12. Were the 

 distribution perfectly equable the proportionate nnndiers instead of 

 beins; 20 to 12 woulil be 10,"7 to 21.'!. The dense grouping therefore 

 between 30(P — 360 and 0' — GO is signilieanl that some speei.al cause 

 has operated in arranging these eonietary perihelia on one and the 

 same side of the sun. In this eonneition it is also interesting to note 

 that the number of meteors encoiuitered by the earth in passing from 

 longitude 27l>''-36(V and ()»— 90^ is about ilmible that met with in 

 moving from 9l>° — 270", anil a partial explanation may be found in 

 the special aceiunidation of cometary jiaths on that side of the sun 

 near the first point of .\ries VThere the earth would be hkely to pick 

 up more fragments than on the opposite side in a region traversal 

 by comparatively few eon.ets. This grouping does not, however, appear 

 to be true of parabolic eomets, ai'-ording to some deductions by 

 Chambers in his Descriptive Astronunii/, but the subject is of sulheient 

 importance to be in\ estigated on the basis of all the materials obtained 

 up to the present time. Though only 32 Jovian comets (including 

 the rertain and doubtfcd instances) are known, it is likely that an\ 

 |>cculiaritv affecting the distribution of these also affects the whole 

 class, which probably numbers siuue hundreds at least, fur in spite of 

 the perseverance and success of comet seekers during the past 

 century, it is certain that a great many short period comets have 

 managed to evade discovery. 



Large Meteors. — In the spring and early summer seasons there 

 is little to offer special attractions to meteoric observers apart from 

 the April Lyrids and May Aquarids. But there are a considerable 

 number of minor showers visible in various parts of the fh-mament, 

 and brilliant fireballs are occasionally recorded. A few bright 

 meteors were obsei-ved in May. 1901, and the following are some 

 particulars : — 



May 11, 14h. 2m. Equal to Sirius. Passed from one-tliird the 

 distance from ^ to ? Draconis to Tj Cephei. Prof. A. S. Herachel, 

 Slongli. 



May 11, Uh. 27Jm. Equal to Vega. Path, 270° - 10" to 

 28.5" -10°. Duration 3 seconds. W. H. Mordoch, Glasgow. 



May U, llh. 3m. Equal to Vega. Path, 12.5 + 30 to 148 + 12. 

 Duration 7 seconds. Prof. Herschel, Slough. 



Mav 15, 9h. 3m. Terv large, and estimated ten times more 

 brillia"nt than Tenus. FeU from altitude 60° due N. to 30° N.W. 

 T). R. Springall. Norwich. 



May 15, lOli. Om. Brilliant meteor of a green hue, and leaving a 

 tail of red sparks. ])as3ed vertically down S. by W. sky, near horizon. 

 Miss L. M. Milncr, Torquay. 



May 10, between llh. and llh. 15m. Large meteor about twice 

 the size of Mars passed from near a Hcrculis througli northern 

 part of Cepheus and disappeared just under the Polar Star. It 

 moved very slowly. W. H. Venables, Tripoli, Barhary. 



May 17, 12h. 25m. Brighter than Jupiter. Travelled from the 

 head of Serpens to N.^., ending between a and >; Boiitis. Dr. 1'. 

 Xoble, Radfield-by-Sittingboume. 



JrLT jrBTEOBS.- With July we have the advent of the most 

 ii.teresting part of the meteoric season. .Alter the middle of the 

 month shooting stars become numerous, and towards the end there 

 are many .Vquarids and Perseids. This year obsei-vations will be best 

 made in the com]>arative absence of moonlight between the lOth and 

 27th, though even at the close of the month and early in August 

 thi*re will be plenty of meteors to record in spite of the presence of 

 OUT satellite. It will be important to watch for the earliest manifesta- 

 tion of the Perseids at about the middle of July, and to deteriuinc 

 the position of the radiant on any and ivcry night wiien a sulRcieiit 

 number of path- have been registered to indicate it satisfactoril\. 



THE 



FACE OF THE SKY FOR JULY. 



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



The Scn.— On the 1st tbe sun rises at 3.48, 

 sets at 8.18 ; on th; alst he ris«js at 4.23, and 



at 7.40. Ho is at his £;fpatost dislaiu'c from the oai'tli oil 

 thf 41h at ."i r.M., his ajiiiaiont ilianii'lor then rouchiiiL;- its 

 iiiiniinaiii vahi(> <if ill' ;io"'7. Tho a]ii>oafaiict' i.i a larui' 

 s|Hil (hiring tho Uittof liall" of May sio^u-osts that tho sun 

 h;is eiitofed on a new period of spot activity. 



The Moon. — The moon will be ftdl on the 1st at 

 11.18 P.M., will enter last qiiartt^r <ni tlu^ !)t.h at :?.'20 a.m., 

 will be new on the 15th at 10.11 p.m., will enter first 

 qnarter on the 23rd at 1.58 p.m., and will be ap;ain full on 

 tho olst at U).34 a.m. The followint; are aiiionu- the 

 oceultations visible at (Treeuwieh durini^ tho month ; — 



The Planets. — Mercury will be an evening star until 

 the 13th, when he will be in inferior conjunction with the 

 siin, and will be a morning star during tht* remaiiuh'r of 

 the mouth. 



Venus is an evening star, but sets about an jiour a.fter 

 the sun throughout the month. On the l-'iili the illu- 

 minated jiart of tbe disc is 0.!}3(), 



Mars is now of little interest to the ob.server, and can 

 only be observed for a short time after sunset. Ou the 

 1st he sets about 11.17 p.m., and on the 31st about 

 9.45 P.M., his apparent diameter dwindling from 6"'2 to 

 5"'4. The planet moves in an easterly path a little south 

 of the stars /3, •/;, and y Virginis. 



Jupiter is fairly well placed for observation, tliough the 

 low altitude places the planet at a disadvantage for 

 observers in our latitudes. His ])ath is retrograde, or 

 westerly, in Sagittarius. On the 1st the meridian passagt 

 is at 11.58 P.M., and ou the 31st at 9.45 p.m., the apparent 

 diameter diminishing from 43"-4 to 42"' 2. The following 

 table iudieat'es the more interesting satellite phenomena 

 at convenient hours . — 



and 

 sets 



Saturn, a little to the east of .Jupiter, is in opposition 

 on the 5th, being on tho meridian at 12.20 a.m. on the 1st, 

 and at 10.14 p.m. on the 31st. On the 21-th, the apjiarent 

 polar diameter of the planet is 17", and the major and 

 minor axes of the outer ring 42"4 and 18"'l respectively, 

 thi^ northern side being turned towards the earth. 



Uranus is fairly well placed for observation, nearly 

 midway betw(^en i) Ophiuchi anil Antares, crossing the 

 meridian at 10.13 p.m. on the 1st and at 8.12 p.m. on the 

 31st. 



Nejitune is too near the sun for observation. 



