Septemuer, 1912. 



KNOWLEDGE. 



359 



Table 39. 



Satellite phenomena visible at Greenwich, l"" e"" 39™ 54' 

 II. Ec. R. ; 3" 5" 50" III. Oc. D. ; 5" 7" 33"" I. Tr. I.; 

 7" 5" 23" I. Sh. E.; 13" 6" 42"" I. Oc. D. ; 14" 6" IS" 



I. Tr. E., 6" 46" III. Sh. E. ; 15" 7" 13" II. Oc. D. ; 17" 6" 8" 



II. Sh. E.; 21" 6" 3" I. Tr. I.; 22" f)*" 19" 22' I. Ec. R. ; 

 24" 6" 1" II. Sh. I.; 29" 5" 13" I. Oc. D; 30" 4" 49" 

 I. Tr. E., 5" 37" I. Sh. E. 



All the above are in the evening hours. 



The eclipse reappearances of I. II. and both phases of 

 those of III. occur high right of the inverted image, taking 

 the direction of the belts as horizontal. 



Saturn is a morning Star. Polar semi-diameter 9l". The 

 major axis of the ring is 46V'. the minor axis 19J". The ring 

 is now approaching its maximum opening and projects beyond 

 the poles of the planet. 



East elongations of Tethys (every fourth given). October 

 2" 2''-l e, 10" i''-3 m, 17" 4''-5 e, 25" 5''-7 m. Dione (every 

 third given). October 2" ll''-2 m, 10" 4'"-2 e, 18" 9''-2 e, 

 27" 2'' ■2 m. 



Rhea (every second given). October 2" 5''-2 e, ll" 5''-9 e, 

 20"6''-7e, 29"7''-3e. 



For Titan and lapetus, E. W. mean East and West 

 elongations, I., S. Inferior and Superior Conjunction, Inferior 



being to the North, superior to the South. Titan, ,3" 5''-6»i \V., 

 7" 4" -2 III S., 11" 7'' -3 III E., 15" 7" -9 III I., 19" 3" -6 m \V., 

 23"2''-0wS., 27"5''-l w E., 31" 5"- 5 m I. lapetus 4" 5" -8 e\V, 

 23"2''-6<.'S. 



Uranus is an evening Star, semi-diameter 2". It is 7i° 

 South of Alpha Capricorni, 5° South-West of Beta. 



Neptune is a morning star, not yet very well placed. 



Meteor Showers (from Mr. Denning's List) : — 



Clusters and Nebulae. 



Table 40. 



CORRESPONDENCE 



STEREOSCOPIC STAR CHARTS. 

 To the Editors of " Knowledge." 



Sirs, — I have read with interest the article in your June 

 number by Mr. A. H. Stuart, on Stereoscopic Star Charts. I 

 should have left to Mr. T. E. 'Heath the task of commenting 

 on the question of priority as to his method of graphically 

 illustrating the relative distances of the stars, but for the fact 



that the author makes the statement that stereoscopic lantern 

 slides of stars have been placed on the market by " an 

 American firm." It was as long ago as May, 1906, that Mr. 

 T. E. Heath, F.R.A.S. approached my firm (Flatters and 

 Garnett, Ltd.) and I then undertook some experiments with a 

 view to reproducing, by a photographic process, the .stereo- 

 graphic charts and transparencies which Mr. Heath had 

 prepared. He had been successful in making the slides by 



