October 1, 1892.] 



KNOWLEDGE 



199 



oh. 59m. P.M., with a northern declination of 6' 50', and 

 an apparent equatorial diameter of iQ-1". On the 12th he 

 rises at 5h. 11m. p.m., with a northern declination of G^ 17', 

 and an apparent equatorial diameter of 49J". This is the 

 day of opposition, the distance of Jupiter from the earth 

 being 36H millions of miles. On the 31st he sets at 

 5h. 6m. .\.M., with a northern declination of 5° 23', and an 

 apparent equatorial diameter of -481". He is occulted b\' 

 the Moon on the evening of the Gth (not visible in England), 

 and the same evening a 9^ magnitude star will be occulted 

 by the planet, the time of central occultatiou being about 

 8h. P.M. During the month he describes a retrograde path 

 in Pisces. The following phenomena of the satellites occur 

 while .JuDiter is more than 8" above and the Sun 8° below the 

 horizon. On the 1st a transit ingress of the shadow of 

 the third satellite at 9h. 47m. p.m., and a transit ingress of 

 the third satellite at llh. 13m. p.m. On the 3rd a transit 

 ingress of the shadow of the second satellite at 7h. 39m. 

 P.M., of the satellite itself at 8h. 11m. p.m. ; a transit ingress 

 of the shadow of the first satellite at 9h. 27m. p.m., of the 

 satellite itself at 9h. ■t2m. p.m. ; a transit egress of the 

 shadow of the second satellite at lOh. 12m. p.m., of the 

 satellite itself at lOh. 36m. p.m. ; a transit egress of the 

 shadow of the first sateUite at llh. ilm. p.m., of the 

 satellite itself at llh. 54m. p.m. On the 4th an eclipse 

 disappearance of the first satellite at 6h. 41m. 58s. p.m., 

 and an occultation reappearance of the same sateUite at 

 9h. om. p.m. On the 10th a transit ingress of the shadow 

 of the second satellite at lOh. 18m. p.m., and of the 

 satellite itself at lOh. 27m. p.m. ; a transit ingress of the 

 shadow of the first satellite at llh. 21m. p.m., and 

 of the satellite itself four minutes later. In this case 

 and the nest transit attention should be paid to a possible 

 projection of the satellite on the shadow. On the 11th 

 an ecUpse disappearance of the first sateUite at 8h. 37m. 5s. 

 P.M., and Its reappearance from occultation atlOh. 49m. p.m. 

 On the 12th an occiUtation reappearance of the second satel- 

 Uteat7h. 29m. p.m. ; a transit egress of the shadow of the 

 first satellite at 8h. 3m. p.m., and of the sateUite itself one 

 minute later. On the 18th an occultation disappearance 

 of the first satelUte at lOh. 21m. p.m. On the 19th an 

 occultation disappearance of the third satellite at 7h. 8m. 

 p.m., of the second at 7h. lom. p.m. ; a transit ingress of 

 the first satellite at 7h. 34m. p.m., and of its shadow at 

 7h. 46m. P.M. ; a transit egress of the first satellite at 

 9h. 46m. P.M. ; an ecUpse reappearance of the third sateUite 

 at 9h. 53m. 46s. ; a transit egress of the shadow of the 

 first sateUite at 9h. 58m., and an eclipse reappearance of 

 the second satellite at lOh. 3m. 7s. It will be observed 

 that for some time this evening, as on the 26th of the 

 month, Jupiter will appear attended only by the fourth 

 sateUite. On the 20th an echpse reappearance of the first 

 satelhte at 7h. 10m. 23s. p.m. On the 26th a transit 

 ingress of the first satellite at 9h. 18m. p.m., of its shadow 

 at 91i. 39m. p.m., an occultatiou disappearance of the 

 second sateUite at 9h. 28m. p.m., an occultation disappear- 

 ance of the third satelUte at lOh. 23m. p.m. ; a transit 

 egress of the first sateUite at llh. 30m. p.m., and of its 

 shadow at llh. 53m. p.m. On the 27th an occultation 

 disappearance of the first sateUite at 6h. 31m. p.m., and its 

 reappearance fi-om eclipse at 9h. om. 43s. p.m. On the 

 28tU a transit egress of the first sateUite at oh. 56m. p.m., 

 of its shadow at 6h. 22m. p.m. ; a transit egress of the 

 second satellite at 6h. 35m. p.m., and of its shadow at 

 7h. 26m. P.M. 



Saturn does not rise on the last day of the mouth tiU 

 3h. o2m. .\.M., and Uranus is in conjimctiou on the 29th. 

 Neptune is an evening star, rising on the 1st at 8h. Om. 

 P.M., with a northern declination of 20" 34'. and an 



apparent diameter of 2-6". On the 31st he rises at 

 6h. 2m. P.M., with a northern declination of 20^ 29'. 

 During the mouth he describes a short retrograde path to 

 the N.E. of e Tauri. 



October is rather a favourable month for observations of 

 shooting stars, the most marked shower being that of the 

 Orionids, from the 17th to the 20th of the month, the 

 radiant point being situated in 7h. Om. k.a. and 15^ north 

 declination. The radiant point rises at the date named at 

 about 8h. 45m. p.m., and sets shortly after 4 a.m. 



The Moon is full (the Harvest Moon) at 6h. 12m. a.m. 

 on the 6th ; enters her last quarter at 9h. 37m. p.m. on 

 the 12th ; is new at 6h. 24m. p.m. on the 20th ; and enters 

 her first quarter at 9h. 26m. p.m. on the 28th. She is in 

 perigee at 5'5h. a.m. on the 7th (distance from the earth 

 222,740 miles), and in apogee at 3-6h. a.m. on the 22nd 

 (distance from the earth 252,590 mUes). The greatest 

 eastern librations take place at Oh. 7m. p.m. on the 2nd, 

 and 8h. 8m. p.m. on the 29th, and the greatest western at 

 lOh. 9m. p.m. on the 10th. 



^Ijcss ([Column. 



By C. D. LococK, B.A.Oxon. 



All coMMrxicATioxs for this columa should be addressed 

 to the " Chess Editor, Knowkdye Office," and posted before 

 the 10th of each month. 



Solution of September Problem (by C. D. P. Hamilton). 



1. B to Kt4, and mates next move. 



CoERECT Solutions received from Betula, G. K. Ansell. 



G. S. Cummimtx. — The criticism may be just, but was a 

 little premature. Black answers 1. Q to Q4 by B to Bsq. 



L. Bourne. — If, as you probably mean, 1. KB x KKtP, 

 Black repUes P to Kt8 becoming a Knight (ch), an effective 

 resource. 



A. <T. Felbiirs. — Thanks for the two-mover, but your 

 key-move fads against the defence 1. . . P to B4 (or 3) ; 

 whereas the problem h solved by 1. P to B3ch, K moves ; 

 2. P to Ql mate. Perhaps, however, the diagram is 

 incorrect ? You speak of 9 White pieces, of which 8 only 

 are visible. 



Betula. — Your last question is the easier to answer. 

 Identical positions resulting from dilierent key-moves must 

 be regarded as practically one and the same problem. The 

 answer to the other question must depend chiefly on (1) 

 the number and (2) the importance of the similar variations. 

 There can of course be no fixed rule : but assuming that 

 a good two-mover contains four leading and more or less 

 original variations A, B, C, D ; and also about four miuor 

 variations, a, b, c, d, then a rough rule might be as follows : 

 " If mine of the leading variations are the same, any 

 or all of the minor variations may occur ; or if one 

 of the leading variations is present (provided it is not the 

 clii'f variation), one or two of the minor variations may 

 occur." Thus, if the original problem is represented by 

 A + B-|-C + D-(-a-)-b-f-c + d,IshouldsaythatE+F + G-)-H 

 + a-|-b-fc-|-d, if by the same composer, might he regarded 

 as a different problem. So also C-|-E-|-E + G-|-a-|-b-i-e-t-f; 

 not, however, A + E-{-F-f G-|-e ff+g-f h, where A Ls a 

 con.spirHvu.sti/ IcmHwi variation. No authority is claimed 

 for this rule, aud much, moreover, must depend on the 

 key-move and general nature of the problem ; but it seems 

 fairly safe to consider the leading variations chiefly, 

 neglecting the minor variations, unless of course these are 

 greatly in excess of the others. 



