SCIENi E-GOSSIP. 



they 



t ii \t-i i RS FOR VOUNG VS1 R( »N( »U 



B\ I i«K C. Dl SHETT. 



I III SI N 



-■I'll. 

 In,. mill. r. I 



is well shown in hrofessorS. I'. Langley's drav 

 .il sun spot, made at the Alleghany I H 

 , 187 :, in. I the brilliant ed| 



i \\ .in, 11 1 1.- 1,1 

 beautiful photograph, dated September 20th, 



I M.I. 



,. leads us 1 ijecl ol the 



irighl spots which ire ;o n visi 



ihe limb, bul generallj seem losl in the 



the middle portions ..1 the disc. 1 h 

 usuall) .1; p ■ much as spots, 



_■ streams. They arc almost alwaj i 



.ml groups near the limb, 



following, 01 eastward side. When 



found on the disc apn n dark spol 



indicate the 



ipots 



but this is no 



:n rule, foi 



the brighl spots 



imes 



irthern 



luthern lati- 



1 u .1 e s, ne v e r 



dark ones. They 

 are usually more 

 difficult obj 

 ibs rve properly 

 than are the dark 



larger telesi 

 show them to the 

 advantage. 

 Very occasionally 

 they may be per- 

 ceived on the limb, 

 seeming to stand 

 out from it almosl 

 hi e little brilliant 

 m .. 11 11 1 a i n s : 

 though it is quite 

 possible that this 

 may be in part 

 due to what is know n ;> 

 saw an instance of this 



10 a.m., bul by 2 p.m. the faculae had disappeared 

 round the limb. Faculae may he readily observed 

 whilst they remain near the limb, lint as they advance 

 on to the disc they pale, and are lost in the greater 

 brilliance of the mi. Idle portions. 



Remarkable outbursts of brilliance occasionally 

 reward the persistent ol. server, as in 1S59, when, on 

 mbei I-:, Messrs. R. C. Carrington and Hodg- 

 son saw a burst ol "flame" over the disc exceeding 

 the solar brilliance. Again on October 2nd, 1864, 

 Btodie saw a very brilliant bodyV or 5" (from 1,800 

 miles to 2,250 miles) in diameter, much brighter than 

 the rest of the disc, travel in one-third of a second 

 1 pathway t', or 27,000 miles, in length, when 

 it seemed to fall through the surface. 



The visible surface of the sun is certainly not solid, 

 otherwise the spots would remain stationary with 

 relation to each other, which is contrary to ob 



tion. Likewise spots having different latitudes give 



Typical Sin Spot ok Dbcbmbbk, 1S7;. 

 After a Drawing by S. /'. LangUy. 



irradiation. The writer 

 on March 5th, 1S99, at 



- results in determining the sun's rotation 

 Notwithstanding this, mil 

 mistaken, spot groups having similai - 



where 

 disappeared • indt 



catc that ! , "" 1 > 



ihere, as the light- 

 supplying surface is called. 



I rom inn. t.. time when very largi [roups 



appe.11. ppeai 



centi 1 meridian, more 1 pei 1 dl) ' [ siderable 



change is going on in the spots at the time; the 



earths magnetism I uch affei ti 



have what is known as a magnetic storm. Usually 



follow a I. '.'. hours lain than the observed 

 phenomenon, as if lime were needed lor the influence 

 1 icross the intervening 93,000,000 miles. 

 Simultaneously then- is frequently a display ol the 

 Aurora. The " northern lights," as they are 

 called in England, are therefore more frequently 

 near the times ol maximum sun spots. 



Whilst alluding to the Aurora it may be well to 



observe that the 

 radiating centre 

 appears not in the 



In . 11. hi ol the 

 pole of the earth, 

 but towards 

 magnetic pole, 

 which is now 

 in;' west of due 

 north as seen in 

 England. Fre- 

 quently the great 

 rays of light. 

 which are gene- 

 rally a distinguish- 

 ing feature of the 

 nieiion.have 

 a slow motion 

 from west t" 



More directly 

 connected with the 

 sun i- the wonder- 

 ful Zodi 

 Light. What its 

 real nature is. 1. 

 little more than 

 conjecture. In ap- 

 pearance 11 is like 

 a cone of light 

 varying in breadth 

 at the base, on the horizon, from io c to 30" 

 according to Hind, and stretching along the course 

 of the ecliptic for some 70 v to IOO^ from the 

 sun'., place. Demonstrably, therefore, 11 must 

 extend to a distance from 'the sun beyond that 

 ,.f the planet Venus, if indeed it does not reach 

 outside the orbit of the earth. Iii appearance 

 11 is .mi unlike the Milky Way. In the tropics it IS 

 always visible after sunset ami before sunrise, but in 

 In, land. February, March and April are the best for 

 evening observations, and September and October for 

 morning appearances. So far only once has its light 

 impressed it. image on the photographic plate. The 

 spectroscope shows a continuous spectrum, making It 

 probable that its light is in reality reflected sunlight. 

 The plane of the Zodiacal Light does not exactlyaccord 

 with that of the .tin's equator, or with thai of the 

 ecliptic, though I approximate very near to ' 

 the former. In shape it is, in my opinion, vertical. 



( To in- continued.) 



