May 1, 1896.] 



KNOWLEDGE 



119 



lOh. 14m. P.M. On the 26th a transit egress of the third 

 sateUite at 9h. 20m. p.m. ; a transit egress of the first 

 satellite at 9h. 48m. p.m. ; a transit ingress of the shadow 

 of the third satellite at lOh. 7m. p.m. ; a transit egress of 

 the shadow of the first satellite at lOh. 55m. p.m. 



Saturn is an evening star, and is in opposition to the Sun 

 on the 5th. On the 1st he rises at 7h. 27m. p.m., with a 

 southern declination of 14' 14', and an apparent equatorial 

 diameter of 17f (the major axis of the ring system being 

 43| in diameter, and the minor 15|' ). On the 13th he 

 rises at 6h. 34m. p.m., with a southern declination of 

 13' 58', and an apparent equatorial diameter of 17f' (the 

 major axis of the ring system being 43^" in diameter, and 

 the minor 15^"). On the 27th he rises at 5h. 33m. p.m., 

 with a southern declination of 13' 42', and an apparent 

 equatorial diameter of 171" (the major axis of the ring 

 system being 43" in diameter, and the minor 15r"). 

 Titan is at his greatest eastern elongation at lOh. p.m. 

 on the 2nd, and 7h. 30m. p.m. on the iSth. He pursues a 

 retrograde path through a barren region of Libra. 



Uranus is in opposition to the Sun on the 12th, and is 

 an evening star, but his great southern declination militates 

 against successful observation in these latitudes. On the 

 1st he rises at 8h. 14m. p.m., with a southern declination 

 of 18° 13', and an apparent diameter of 3-8''. On the 31st 

 he rises at 6h. 9m. p.m., with a southern declination of 

 17° 56'. He pursues a retrograde path in Libra. 



Neptune has left us for the season. 



There are no very well-marked showers of shooting stars 

 in !May. 



The Moon enters her last quarter at 3h. 25m. p.m. on 

 the 4th ; is new at 7h. 46m. p.m. on the 12th ; enters her 

 first quarter at (Jh. 21m. a.m. on the 20th ; and is full at 

 9h. 57m. p.m. on the 26th. She is in apogee at 3h. p.m. 

 on the 8th (distance from the Earth, 252,050 miles), and 

 in perigee at lib. a.m. on the 24th (distance from the 

 Earth, 225,080 miles). 



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



Communications for this column should be addressed to 

 C. D. LococK, Burwash, Sussex, and posted on or before 

 the 10th of each month. 



Solution of April Problem. 



(C. A. Kennard.) 



Key-move. — 1. R to QBsq. 



If 1. ... K to Q4, 2. K to B3, etc. 

 1. ... P to Q4, 2. E to K2, etc. 



The "curiosity" lies in the fact that if White could 

 make a waiting move there would be a second solution : for 

 after 1. K to Q4, 2. P to (^'4, and mates next move. 



Correct Solutions received from Alpha, J. T. Blakemore, 

 A. Walker, W. WiUby. 



B. P. (ireij. — There is hardly enough variety in your 

 problem, considering the force employed. 



W, Willby. — It was certainly an unusual feat. 



A. C. Ch alien //(')■. — Many thanks for the problems, 

 especially the three-mover. 



ir. M. A. A'.— After 1. K to Kt2, P to Q4 ; 2. R to K2, 

 K to QG, there is no mate. 



G. B. Fraser, A. E. BniiiiaU, and A Norseman. — Your 

 communications have been forwarded to our correspondent. 



PROBLEMS. 



By A. C. Challenger. 



No. 1. 



Black (5). 



X. -mm. wm 'mm. 



fM 





^ ^^^"^^^^'^'''^^ 



White (6). 



White mates in two moves. 

 No. 2. 



Black (8). 



iw^iMir 



m 'mm ^ MM 





White (h). 



White mates in three moves. 



THE EIGHT QUEENS PROBLEM. 



Some correspondents have sent us some remarks on this 

 problem which may tend to explain the law which governs 

 it. 



Mr. W. W. Strickland shows that the paucity of solutions 

 on a board of thirty-six squares (using six Queens) is 

 connected with the fact that the solution is impossible 

 when a Queen stands in the centre of one of the four 

 quarters of the board. From other considerations he 

 predicts that on a board of eighty-one squares there will 

 be found only six essential methods of solving the problem. 

 Perhaps one of our readers might care to verify this. 

 Mr. C. W. Branch suggests the law which governs the 

 convertibility or otherwise of the positions. He imagines 

 a position set up on nim chess-boards placed in the form 

 of a square. If, then, any piece on one of the outside 

 chess-boards is in a line with any piece on the central 

 board, the central position cannot be moved in such 

 a direction as to cause the attacking piece to be brought 

 on to the central board, unless such movement at the same 

 time causes the piece attacked to disappear from the 

 central board. 



Wo regret that it is impossible to print the diagrams 

 which accompany this ingenious explanation. 



