46 



KNOWLEDGE. 



[Fbbruaby 1, 1895. 



often unrecognized by tlieir contemporaries, endeavour to 

 carry out to the fiUl prevention, which is better, and cure, 

 which is good. 



We are indebted to Messrs. J. and A. Cliurcliill for their kind 

 permission to use tbe two foregoing illustrations, which are taken 

 from Stevenson and Murphy's "Treatise on Hygiene." 



THE FACE OF THE SKY FOR FEBRUARY. 



By Herbert Sadler, F.K.A.S. 



SOME fine groups of spots have recently appeared on 

 the solar disc. Conveniently observable minima 

 of Algol occur at 9h. 26m. p.m. on the 4th ; at 

 6h. lorn. P.M. on the 7th ; at llh. 8m. p.m. on the 

 24th ; and at 7h. .57m. p.m. on the 27th. 

 The Zodiacal Light should be looked for after sunset in 

 the south-west during the absence of the Moon. 



Mercury is an evening star, and is fairly well situated 

 for observation during the first fortnight of the month. 

 On the 1st he sets at 6h. 10m. p.m., or lb. 22m. after the 

 Sun, with a southern declination of 13° 11', and an 

 apparent diameter of 5f ", Tij%ths of the disc being illu- 

 minated. On the 5th he sets at 6h. 31m. p.m., or 

 Ih. 35m. after the Sun, with a southern declination of 

 10° 19', and an apparent diameter of Gj", yVo'^^ o^ '^^ 

 disc being illuminated, and the planet being now at his 

 brightest. On the 10th he sets at 6h. 50m. p.m., or 

 Ih. 47m. after the Sun, with a southern declination of 

 7° 1', and an apparent diameter of 7 J", yjnjths of the disc 

 being illuminated. On the 16th he sets at 6h. 46m. p. jr., 

 or Ih. 22m. after the Sun, with a southern declination of 

 4° S3', and an apparent diameter of 8|'', -i^gths of the disc 

 being illuminated. After this he approaches the Sun too 

 closely to be observed. He is at his greatest eastern 

 elongation (18|°) at 5h. p.m. on the 9th, and in inferior 

 conjunction on the 25th. At Ih. p.m. on the 1st he is in 

 conjunction with Yenus, 0° 35' to the north of her ; and 

 again at the same hour on the 10th, 2° 38' to the north of 

 her. These conjunctions will afford excellent opportunities 

 for picking up the planet on the evenings of the 1st and 

 10th. ^Yhile visible Mercury describes a direct path in 

 Aquarius, being near the 5^ magnitude star 38 Aquarii on 

 the evening of the 2nd. 



Venus is an evening star, and is gradually getting into 

 a better position for observation. She sets on the 1st at 

 6h. 7m. p.m., or Ih. 19m. after the Sun, with a southern 

 declination of 13° 46', and an apparent diameter of 10^^", 

 Y^o'^ths of the disc being illuminated. On the 10th she sets 

 at 6h. 36m. p.m., or Ih. 34m. after the Sun, with a southern 

 decUnation of 9° 40', and an apparent diameter of 10|^", 

 yVo*''i3 0^ '^^ disc being illuminated. On the 20th she 

 sets at 7h. 8m. p.m., or Ih. 47m. after the Sun, with a 

 southern declination of 4° 42", and an apparent diameter 

 of IO-2", x5*ot*is o^ ^^^ ^^^'^ being illuminated. On the 28th 

 she sets at 7h. 35m. p.m., or two hours after the Sun, with 

 a southern declination of 0° 34', and an apparent diameter 

 of lOf", Tost't's of the disc being illuminated. We have 

 alluded above to her conjunctions with Mercury. During 

 the month she pursues a direct path through Aquarius into 

 Pisces, but does not approach any conspicuous star very 

 closely. 



Mars is an evening star, but is rapidly getting fainter 

 and smaller. He sets on the 1st at Ih. 40m. a.m., with a 

 northern declination of 17° 39', and an apparent diameter 

 of 8-0", the phase on the n f limb amomiting to 0-9". 

 On the 15th he sets at Ih. 27m. a.m., with a northern 

 declination of 19° 46', and an apparent diameter of 7 1". 

 On the 28th he sets at Ih. 18m. a.m., with a northern 

 declination of 21° 31', and an apparent diameter of 6". 



He is in quadrature with the Sun on the 5th. During the 

 month he passes through a portion of Taurus into Aries, 

 being south of the Pleiades on the 19th. 



Jupiter is an evening star, and is esceUently situated 

 for observation. He sets on the 1st at 5h. 18m. a.m., 

 with a northern declination of 23° 18', and an apparent 

 equatorial diameter of 44-1". On the 11th he sets at 

 4h. 37m. A.M., with a northern declination of 23° 18', and 

 an apparent equatorial diameter of 42'9". On the 21st 

 he sets at 3h. 57m. a.m., with a northern dechnation ot 

 23° 20', and an apparent equatorial diameter of 41-6". On 

 the 28th he sets at 3h. 30m. a.m., with a northern 

 declination of 23° 21', and an apparent equatorial diameter 

 of 40-6". During the month .Jupiter is almost stationary 

 in Taurus, about 1J° south-east of the 5th magnitude star 

 132 Tauri. The following phenomena of the satellites 

 occur while the Sun is more than 8° below and Jupiter 8° 

 above the horizon : — On the 1st a transit egress of the third 

 satellite at 6h. 17m. p.m. ; a transit ingress of its shadow 

 at 7h. 9m. p.m., and its egress at lOh. 6m. p.m. On the 2nd 

 an occultation disappearance of the second satellite at 

 Oh. 9m. A.M. On the 3rd an occultation disappearance of 

 the first satellite at Ih. 36m. a.m. ; a transit ingress of the 

 second satellite at 6h. 31m. p.m., a transit ingress of its 

 shadow at 8h. 24m. p.m., a transit egress of the second 

 satellite at 9h. 8m. p.m. ; a transit ingress of the first 

 satellite at lOh. 52m. p.m. ; a transit egress of the shadow 

 of the second satellite at llh. 3m. p.m. ; a transit ingress 

 of the shadow of the first satellite at llh. 50m. p.m. On 

 the 4th a transit egress of the first satellite at Ih. 9m. a.m., 

 and a transit egress of its shadow at 2h. 7m. a.m. ; an 

 occultation disappearance of the first satellite at 8h. 3m. p.m., 

 and its eclipse reappearance at llh. 16m. 80s. p.m. On 

 the 5th an eclipse reappearance of the second satellite at 

 5h. 52m. 22s. a.m. ; a transit ingress of the shadow of the 

 first satellite at Ch. 19m. p.m., a transit egress of the 

 satellite itself at 7h. 36m. p.m., and of its shadow at 

 8h. 36m. p.m. On the 8th a transit ingress of the third 

 satellite at 7h. Om. p.m., its transit egress at 9h. 51m. p.m., 

 and a transit ingress of its shadow at llh. 8m. p.m. On 

 the 9th a transit egress of the shadow of the third satellite 

 at 2h. 7m. a.m. ; an occultation disappearance of the 

 second satellite at 2h. 30m. a.m. On the 10th an occultation 

 disappearance of the first satellite at 3h. 25m. a.m., a 

 transit ingress of the second satellite at 8h. 56m. p.m., a 

 transit ingress of its shadow at llh. 2m. p.m., a transit 

 egress of the satellite itself at llh. 33m. p.m. On the 

 11th a transit ingress of the first satellite at Oh. 41m. a.m. ; 

 a transit egress of the shadow of the second satellite at 

 Ih. 42m. A.M. ; a transit ingress of the shadow of the first 

 satellite at Ih. 45m. a.m., and a transit egress of the 

 satellite itself at 2h. 57m. a.m. ; a transit egress of the 

 shadow of the fourth satellite at 6h. 8m. p.m. ; an occulta- 

 tion disappearance of the first satellite at 9h. 52m. p.m. 

 On the 12th an eclipse reappearance of the first sateUite 

 at Ih. 12m. 6s. a.m. ; a transit ingress of the first satellite 

 at 7h. 8m. p.m., of its shadow at 8h. 14m. p.m. ; an eclipse 

 reappearance of the second satellite at 8h. 27m. 44s. p.m. ; 

 a transit egress of the first satellite at 9h. 25m. p.m., and 

 of its shadow at lOh. 31m. p.m. On the 13th an eclipse 

 reappearance of the first satellite at 7h. 40m. 56s. p.m. 

 On the 15th a transit ingress of the third satellite at 

 lOh. 37m. P.M. The fourth satellite is in superior 

 geocentric conjunction at lOh. 54m. p.m. on the 2nd. On 

 the 16th a transit egress of the third satellite at Ih. 29m. 

 A.M., and a transit ingress of its shadow at 8h. 8m. On the 

 17th a transit ingress of the second satellite at llh. 24m. 

 P.M. On the 18th a transit ingress of the shadow of 

 the second satellite at Ih. 40m. a.m., a transit ingress of 



