TTIK FACE OV TIIl^: SKY FOK 1-FRRl'AHV 



I'.v A. 



(■K()Mmi;lin. I'.. a., d.s,,, i.k.a.s. 



Tabi.i-; 1. 



Tabi.1-; 2. 



P denotes the position angle of the axis of tlie body measured 

 castwaid, from the North Point of the disc. R is the 

 Hchographical (Planctographical) latitude of the centre of the 

 disc. L denotes the longitude of the centre of the disc, T the 

 time of transit of the zero meridian across the centre of the disc. 

 In the case of Jupiter there arc two systems of longitude, I, 

 tor the ctjuator, II. for the temperate zones. To find intcrnic- 

 diate values of T apply nniltiples of 24" i9"'.9^ SOi". 9" .S-ir,'" 

 for Mars, Jupiter I and II, respectively. Throughout these 

 not(>s the time used is Greenwich Civil Time, day commencing 

 at midnight, and the letters /;;, c. stand for morning and 

 evening. O, q. for Mars are the position angle and amount 

 of the greatest defect of illmnination. 



The Six moves North fairly rapidlv during February. 



His semi-diameter diminishes from 16' 15" to 16' 10". Sunrise 

 and sunset at (Greenwich, Feb. 1.7''4.i"' ;;/, 4'' 45'" c ; Feb. 

 29, 6" 50™ in, 5" .?6"' e. 



The Moon is I-'ull. l-~eb. 2'' ll'' 58"' c : Last (J., Feb. 10'' o" 

 51"" III ; New, Feb. l.S'' 3'' 44"" ;» ; First O., Feb. 25'' 7" 27"' c ; 

 Nearest Earth, Feb. 2** 2'' in, semi-diameter 16' 42"- 8 ; Furthest 

 away, Feb. H** ll'' n;, semi-diameter 14' 44"-,^; Nearest March. 

 1'' t)" in. semi-diameter, 16'30"-4. Greatest Libration 7° S. 

 Feb. 1 ; 7° VV. Feb. 7 ; 7° N. Feb. 15 ; 6° E. F"eb. 23 ; 7° S. 

 Feb. 28. The letters N. E. S. W. indicate the region 

 of the Moon's limb (referred to our sl<y) carried into view- 

 by libration. Observers should watch their librational 

 opportunities to increase our knowledge of the regions near 

 the limbs. 



Tabi.i; 3. Oeciiltations of stars bv the Moon visible at Greenwich. 



