1915] on the Total Solar Eclipse of 1914 365 



disposed equatoriallj at such periods. At times of " intermediate " 

 activity, when the sun-spot curve is rising towards a maximum, or 

 faUing towards a minimum, we should expect the wings to extend 

 to higher latitudes and lower latitudes. This, too, is verified ; the 

 long equatorial wings of the minimum period assuming the form of 

 four petals of a single dahlia. Sometimes sheaves of bright streamers 

 are in addition projected across this winged background. Such were 

 the coron^e of 1886, 1896, and 1898. A curve of limiting latitudes 

 of the greater sun-spot disturbances reflects in it^ variations very 

 closely the positions of the main wings of the corona. 



At periods of maximum solar activity large and active spot 

 centres are found in all latitudes, within the limits 20" X. and S. 

 The streamers proceeding from such regions of activity would be 

 projected in all possible directions around the sun, when viewed in 

 two dimensions, from the earth, and would be sufficient to give the 

 appearance of such coronae as those of 1882, 1893, and 1905. The 

 areas of sun-spot activity at such periods are also the areas of bright 

 faculse, of extensive overlying flocculi, and of the more violent out- 

 bursts of metallic and active prominences. It seems to be probable 

 that these disturbances, focused on sun-spots, are more responsible 

 for the irregular form of the corona at maximum than the prominences 

 alone. In this view of the matter the wings are covered over by 

 the projected images of streamers radiating in all directions. 



In a research communicated to the Royal Astronomical Society * 

 in the year 1913, evidence was adduced in the cases of four eclipses, 

 namely, those of 1893, 1898, 1905, and 1908, of the existence in the 

 sun's corona of bundles of rays, diverging apparently from narrow belts 

 of areas of long-continued sun-spot disturbance. Moreover, the areas 

 of disturbance had been connected with series of magnetic storms on 

 earth, thus suggesting that the mode of propagation of the sun's 

 influence which is operative in magnetic storms is represented by 

 the stream lines of the solar corona. In these cases the areas of 

 sun-spot disturbance had been near the limb of the sun. 



The eclipse of 1914 took place when the sun-spot curve was rising, 

 the mean daily area of spots in 1914 being about twenty times what 

 it had been in 1913, which was the year of absolute minimum. The 

 largest spot of the year was on the disk, being of considerable size, 

 in north heliographic latitude 18' 18' and longitude 67' 18'. But 

 it was situated about 68' from the west limb. It has already been 

 noted that superposed on the coronal wings X.AV. were two bright 

 streamers, and above them a very bright filament at position angle 

 356°, and over the E. wing a sheaf of bright rays constituting the 

 N.E. streamer. Is it possible that these striking features of the 

 solar corona, which are mainly responsible for differentiating it from 

 the minimum type, were connected with the area of disturbance of 



* Monthly Notices, R.A.S., vol. Ixxiii. Nos, 6, 7. 



Vol. XXI. rXo. 109) 2 b 



