SOLAR DISTURBANCES DURINCx SEPTEMBER, igii. 



I'KAXK C. DENNETT. 



Di;king September the Sun's disc .ippeared to be without 

 disturbance, bright or darl;. on the IJth. 15th to 20th. 25th and 

 JOth. .All disturbances after the lOth were faculic only. The 

 lonfj'itude of the central meridian on September Ist was 

 325= 45'. 



No. 36. — The only spot disturbance during the month. It 

 was first seen as a moderate spot, about eleven thousand miles 

 across, with a bright bridge over its umbra, on September the 1st, 

 and a trail of spotlets extending towards the North- East. The 

 bridge over the umbra was an interesting object until the 6th. 

 and on the 5th it showed complicated detail, and was double 

 in a part of its length. On this date the spot seems to have 



faculic knot show(^d just ahead of the group in which pores 

 appeared to be dc\eloping. but it disappeared again. The 

 group sometimes presented a very interesting appearance in 

 the spectroscope. On the 1st the Ha line showed displace- 

 ments both on the red and violet sides, with dull reversals, 

 wtiilst the D:i line of helium was seen dark. Next day the 

 distortion was less, but small dark hydrogen flocculi were 

 visible around, as w-ell as small projected prominences. ( )n 

 the 5th a pale prominence in the rear of the leader was visible, 

 and also small dark hydrogen flocculi. with the helium line 

 showing duskv. 



The dotted areas in the diagram show the position of 



DAY OF .SEPTEMISHR, 191 i. 



0' 10' 20' 30' W 5C' 60' 7Cr 90' 90" lOff HO' l?0' 130" 140" ISO' W (7(3' 'W 190' JOO' 210" 220' 230' IW 250" 260' 270' 280" 290" 300" 310" 320" 330" 34-0' 350" 360" 



attained its greatest area — fifteen thousand miles by elev n 

 thousand miles. From the 1st until the 7th. the inner edge 

 of the penumbra appeared to be fringed more brightly, and 

 on the 7th and Sth. the bright photospheric substance 

 broke through the penumbra on the southern side. On the 

 10th. the place of the spot was marked by three closely 

 packed umbrae which had disappeared by next day, the 

 site being marked by faculae seen also on the 12th. On the 

 2nd the three more distant spotlets had broken into one 

 with a long umbra, which again broke up very quickly. The 

 pores were subject to rapid change. On the 4th. 6th and 7th. 

 a little pilot pore was evident just west of the leader, and on 

 the 6th and .Sth. pores showed a little towards the south. The 

 maximum length was fiftv-six thousand miles. ( )n the 2iid a 



faculic disturbances. I\aculae were seen on the 1st and 

 2nd near longitude 256 . X. latitude 50°. and 26". N. ii°. On 

 the 1st, 2nd and 12th near 260°. S. 13°. On the 4th and 5th. 

 at 225°. S. i ■. another at 215=. S. 15'.on 4th, with another at 

 202°. S. 4°. on 5th and 6fh. The group at 320°— 340°. S. 13" 

 — 20° were visible September 22nd to 24th. 



Notwithstanding the fewness of disturbances visually seen 

 upon the disc, there are still a fair number of prominences 

 around the limb. On -the 24th there were a number of 

 eruptions recorded showini; '#!at the chromosphere was in a 

 very active condition. 



The Chart is constructed from t'^e observations of Messrs. 

 1. McHarg. .\. \. Bus^. E. E. Peacock, and F. C. Dennett. 



NOTICES. 



ML'SEUM WORK.— Particulars of a 

 vacancy for a pupil (who will be paid a 

 small salary) in a nuiseum, can be obtained 

 on application to the Editors of " Kxow- 

 I.EI1GK," at 42, Bloomsbnry Square, 

 London, W'.C. 



CHEMICAL ALPAKATUS.— We have 

 received from Messrs. Gallenkamp and 

 Company, Limited, Part 1 of their 

 catalogue of General Chemical Apparatus 

 and Laboratory Accessories for the Session 

 1911-12. It measures seven by clc\cn 

 inches and consists of more than eight 

 hundred pages. Messrs. Gallenkamp claim 

 to have the most varied stock in England, 

 and their price list is certainly excellent 

 e\-idcnce in favour of this contention. 



HORTICULTCRAL HOOKS.— Messrs. 

 John W'eldon & Company's Catalogue of 

 Gardening Books and Papers, which has 

 jiisl reached us, contains no less than one 

 thousand and eighty-five items and should 



l-'rnnr a />hi>li>t:' II/--1 i-y U. /•'. Ilt'iiy. 



A Gibraltar .Ape. 

 452 



prove exceedingly interesting to all who are 

 occupied in the art which we are told 

 " doth mend nature." 



HARBAKY APES AT GIBRALTAR. 

 — In Tltc Sclbonic Magnsinc for 

 N'i>\'eiiiber, Mr. (L B. Hony gives the 

 following account of the .Apes of Gibraltar. 

 He says : — " At the present time there are 

 only eleven apes on the rock, eight females 

 and three males. Of these onl\' three are 

 of the original Gibraltar stock. The 

 remainder ha%e been imported from \arious 

 parts of .Africa, and there are altogether 

 specimens of four distinct races. They have 

 not bred on the rock for years, but fresh stock 

 having been imported, it is hoped that there 

 will soon be some ' home-bred ' ones. The 

 first time I saw them there were six 

 together ; they were very shy, and my 

 repeated efforts to get photo.graphs failed." 

 .Afterwards Mr. Hony succeeded, and one 

 of his pictures is here reproduced. 



