NfARCH. 101: 



KNOWLEDGE. 



01 



from Dungencss to Dover, where i'',-.'., of the Sim's diameter 

 are covered. The smallest occurs in the island of Lewis 

 where the magnitude is r",;-,-,. (It may be mentioned that the 

 central line of the annular eclipse of 1921 crosses Lewis.) 



The following table gives particulars of the eclipse for 

 various British Stations. The times are in Greenwich time 

 e.\cept for Ireland, where they are in Dublin time. The letters 

 in, e are not inserted, as they can readily be inferred, the 

 eclipse being in the middle of the day. 



4" 35"": I. Kc. D. 10'' ll'' 44"' 45" c; I. Oc. R. 11" 2" 58""; 



I. Tr. K. U" 0" .V" : II. He. D. 14"" l" IS"" 56" ; III. Ec. R. 

 1.5'' 0" 50"' 57". III. Oc. D. 2*' 58"'. III. Oc. R. 4*' 52'": 



II. Tr. E. 16'' 0" 5'V"; I. Sh. I. 17'' 4" 15"": I. Ec. D. 

 IS'' 1" iS"" 13", I. Oc. R. 4'' 45"": I. Tr. I. IS"" ll*" 39"'e; 



I. Sh. E. 19'' 0''57'".l.Tr. E. l" 52"'; I. Oc. R. 19'' ll'' \2"'c; 



II. Ec. D. 21'' a*" 53"" 26": III. Ec. D. 22'' 3''0"' 17", III. Ec. R. 

 4" 49'" 39"; II. Sh. I. 22'' lO" 59" c : II. Tr. I. 23' O" 43"'. 

 II. Sh. E. 1" 38", II. Tr. E. 3" 20"'; I. Ec. D. 25' 3"' 31'" 43": 



The angles are measured from North Point or Verte.\ 

 towards the East. The partial eclipse is visible in Eastern 

 .America, throughout Europe. Northern Africa, and Western 

 and Central .Asia. 



Mercury is fairly well placed as an evening star at the 

 beginning of the month, setting in England about l^ hours 

 after the Sun ; diameter 9", J of disc illimiinated. It is in 

 inferior conjunction on the 15th. It is 3j° West of the Sun 

 during the eclipse on the 17th, but, being such a thin crescent 

 will scarcely be seen. At the end of the month southern 

 observers will see it as a morning star; diameter 10", h of 

 disc illuminated. 



Venus is still a morning star, better placed for southern 

 observers than in England. Her diameter diminishes from 

 11" to 10", ^i of the disc are illuminated. She will be some 

 20" South-west of the Sun during the eclipse, and will doubtless 

 be readily discernible in all places where the eclipse is large. 



Mars is an evening star. Its disc is becoming too small 

 for useful work. The diameter diminishes from 6" to 5". It 

 is 20' South of f Geminorum on April 21st. 



Jupiter is now well away from the Sun, and favourably 

 placed for southern observers. The polar diameter increases 

 from 38" to 41". The equatorial is 2f' greater. Defect of 

 illumination 4". The diagram shows the configuration of the 

 four large Satellites at 2'' m, for an inverting telescope. 



Phenomena visible at Greenwich (all in the morning hours 

 unless marked c) :— I. Ec. D. 2^ 3" 23" 1" ; I. Sh. I. 3'' O" 29". 

 I. Tr. I. 1" 36". I. Sh. E. 2" 42". I. Tr. E. 3" 49": 



I. Oc. R. 4" 1" 9". III. Sh. I. 4" 49": II. Sh. I. 5" 4" 32"; 



II. Oc. R. 7'' 3" 31": III. Oc. R. 8" l" 17": I. Ec. D. 

 9* 5" 16" 26= ; I. Sh. I., lO" 2" 22", I. Tr. I.. 3" 25". I. Sh. E., 



I. Sh. I. 26'i0'' 37". I. Tr. I. l" 26". I. Sh. E. 2*' 51", I. Tr. E. 

 3" 38" : I. Oc. R. 27'' O'' 58" ; II. Sh. I. 30" l" ii"'. II. Tr. I. 

 3" 2", II. Sh. E. 4'' 12". 



S.\TURN may still be seen as an evening star, but is drawing 

 near the Sun. It is 23° East of the Sun on the 17th. and may 

 be seen on the central line of the eclipse. 



Uranus is a morning star, still badly placed. 



Neptune is an evening star, still within the limits of the 

 map given in " Knowledge " for December. 



Meteors. — The following radiant points are due to Mr. 

 W. F. Denning. 



Minima of Algol (period 2'' 20" 49"), every third 

 minimum given. April 1" 11" We, 10" l" 41" c, 19" 4" 8"m, 

 27" 6" 35"e. 



