SCIENCE-GOSSIP. 



193 



/iSTRONGMY, 



CONDUCTED BY FRANK C. DENNETT. 



Sun 



Moon 



Dec. 



28 



Mercury... 8 



Venus 



Jupiter . 

 Saturn , 

 Uranus . 

 Neptune . 



28 



Rises, 

 h.m. 



7-55 a.m. 

 8.5 

 8.9 



Rises. 

 II. 13 a m. 

 2.3 p.m. 

 1.6 a.m. 



Souths. 



h. m. 



0.15 p.m. 



0.46 



1. 14 



2.38 



2.^9 



2.58 



o.ii a.m. 

 11.9 p.m. 

 10.17 



4.59 a.m. 



9.42 



9.48 

 II. 19 p.m. 



Sets, 

 h.m. 

 .. 3.49 p.m. 

 .. 3.50 

 ... 3-56 



Souths. 

 ... 3.32 p.m. 

 ..10.55 

 ... 6.27 a.m. 



Semi 

 Diameter. 

 ... 2" 3 

 ... 2" 5 



Position at Noon. 



R.A. 



Dec. 

 22° 49' S. 

 23° 25' 

 23° 15' 



•• 7" ; 



h.m. 

 173 •• 

 17.48 .. 

 18.32 .. 

 Sets. 

 8.2 p.m. 

 6.50 a.m. 

 "•33 



Position at Noon. 

 R.A. 



Dec. 

 24° 53' S. 



23' 



23' 



h.m. 

 .. 17.26 

 .. 18.36 

 .. 19.44 

 ,.. 1948 

 .. 20.39 

 .. 21.27 

 •• 5-19 

 .. 5-2 

 ... 4.49 



16° 58' 



22' 

 22' 

 14' S. 



34' 



15.36 ... 17'' 

 15-38 ... 19° 



5. II ... 2I-' 



39' N. 

 38' 



28' 



47' N. 

 17' S. 

 12' S. 

 32' N. 



h.m. 

 Dec. 12 ... 0.29 a.m. 

 ,, 27 ... 0.9 p.m. 



Moon's Phases. 

 h.m. 



New ... Dec. 4 ... 5.51 p.m. jst Qr. ... 



Full ... „ 20 ... 4.5 a.m. ^rd Qr. ... 



Sun. — Spots may still be expected to be few and 

 small, though there is a slightly increased activity. 



Mercury, from its nearness to the sun in the 

 early part of the month and great southern declina- 

 tion later on, is badly placed for observation. 



Venus is an evening star, setting on December 

 30th at 7.38 p.m., but is too far south for good 

 observation. 



Mars, being in opposition to the sun at 6 a.m. 

 on December nth, is in its best position for obser- 

 vation, though its small angular diameter is not 

 favourable for the easy study of its details. Jt is 

 visible all the night. 



Jupiter rises at 11. i p.m. on December ist, and 

 at 9.15 on 31st, and is in position for observation 

 until sunrise. On the morning of the 13th, at 3.29, 

 the outer satellite, iv., enters upon the disc, 

 passing off at 7.54. On the 20th, at 10.7 p.m., iii., 

 the largest moon, passes on to the disc, and off at 

 1.38 on the morning of the 21st. They may 

 probably appear as dark spots when they are near 

 the middle part of the transit. 



Saturn and Uranus are too close to the sun for 

 observation. 



Meteors should be specially looked for on 

 December 8th, gth, nth, 12th and 21st. 



Variable Stars. — During December the follow- 

 ing may be looked for : 





R.A. 



Magnitude 







h.m. 



Dec. Max. Mm. 



Period. 



« Aurigffi 



4-52 



43" 3/ N. 3-5 4-5 





R. „ 



.Vfa 



53° 26' N. 6-6 127 



127 days. 



R. Leporis 



4-53 



15° 0' S. 6'0 9'o 



439'0 days. 



15, S. Monocerotis 



b.3S 



10° 2' N. 4-9 5 6 



3d. ioh.48m 



a Orionis 



548 



7° 22' N. 10 1-4 



Irregular. 



5 •• 



5.24 



0° 24' S. 2'2 27 





Minima of the star Algol should occur December 

 3rd, II. 5 p.m.; 6th, 7.54 p.m.; 26th, 9.36 p.m.; 

 and 29th, 6.25 p.m. 



The Study of the Sun's Surface. — A good 

 way to make a general examination of the disc is to 

 allow the image projected from the eyepiece to fall 

 on a white card, when it can be examined by a lens, 

 both for dark spots and bright (facula;), any special 

 details can then be examined directly, the dark cap 

 being screwed on the eyepiece, or, better still, a 

 properly constructed solar eyepiece. For the study 

 of large spots, a tiny pinhole diaphragm in an ordi- 

 nary astro-eyepiece is most useful, permitting the 

 nuclei to be observed in the umbrae, adding much 

 to the marvellous structure which these spots 

 reveal. Changes take place in these spots very 

 rapidly sometimes. In a large spot visible early in 

 November, such changes took place, involving 

 immense areas, in the interval between 11.30 a.m. 

 and 2.45 p.m. on November 6th. 



The Great Group of Sunspots visible in the 

 middle of September, was a truly remarkable 

 object, occupying forty-four hours crossing the 

 central meridian. The area covered by the gigantic 

 disturbance was, in round numbers, 2,400,000,000 

 square miles. It is remarkable that amongst the 

 spots forming the group there was a constant 



recurrence of a double umbra. This will be 

 noticed in the reproduction which we give of the 

 Greenwich photograph taken September i6th, 

 and very kindly forwarded to us by the Astronomer 

 Royal for that purpose. A remarkable object was 

 the little black pilot spot which preceded the main 

 group. 



We are sorry to have to record the sudden 

 death of M. Francois Felix Tisserand, Director 

 of the Paris Observatory, in his fifty-second year. 

 He received his degree of Doctor of Science in 

 1S68, and entered Paris Observatory as assistant 

 astronomer. In 1S71, he was appointed Director 

 of Toulouse Observatory and Professor of .Vstro- 

 nomy. The transit of Venus, in 1S74, led him to 

 travel with M. Janssen to Japan to observe it, 

 and in the same year he received the red ribbon of 

 the Legion on Honour. Since iSSi, he has been 

 a Foreign Associate of the Royal Astronomical 

 Society. After the death of Admiral Mouchez, he 

 was appointed, in August, 1892, Director of the 

 French National Observatory. Since 1SS6, a great 

 deal of his attention has been given to the produc- 

 tion of his great treatise on mathematical astronomy, 

 " Traite de Mecanique Celeste. 



