540 THE POPULAR SCIENCE MONTHLY. 



fast, while the other is left free. This is so very generally the case 

 that we see that, if these filaments be clouds, they differ from ours in 

 other circumstances than their shape. Those w^e are studying are bent 

 into curves, which show that the solar winds frequently move in cir- 

 cular sweeps, and are, to a considerable degree, comparable with our 

 cyclones. Long, twisted ropes are sometimes formed by them, one 

 being thrown over another ; and, in cloud-like masses, they at times 

 move over and conceal lower portions of the penumbra — the abrupt 

 changes in the directions of motion showing us that these are super- 

 posed strata of what, for want of a better word, we must call solar 

 clouds, which drift across each other's course occasionally, nearly at 

 right angles, while the ever-moving whirlwinds leave an unmistakable 

 record of their action on these pliant forms. 



In one j^art of the spot, one of these has been bent into a complete 

 loop, or closed curve, the extremity showing a fringe of ragged strands, 

 like that of a broken rope. The immensely more extended scale of the 

 action here being kept in view, and the fact that the whole spot is 

 being changed in all its parts — even while we are looking at it — by 

 alterations which, though apparently gradual, are really the indications 

 of an immense energy, it will be seen that, considered merely as a 

 spectacle of the play of natural forces, we have before us something 

 almost incomparably greater than any which the terrestrial volcano, 

 earthquake, or cyclone, can offer. The entire surface of the earth, were 

 it spread out into a plain, would be, in fact, of inconsiderable size as 

 compared with either branch of the spot we are examining. 



The quickness of the transformations that the observer sometimes 

 notes here is wonderful. Lockyer, Young, and other observers, have 

 demonstrated the existence of chromospheric movements, in some in- 

 stances, at the rate of over 100 miles a second; and the velocities 

 in the photosphere are,' occasionally, of a similar order of magni- 

 tude. As an instance, it may be mentioned that tlie loop in question, 

 which inclosed an area of about 3,000,000 square miles (not far 

 from that of the United States), broke up, and seemingly melted away, 

 like a snow-wreath before a fire, in little over a quarter of an hour. 

 How vain the attempt must be to adequately realize to ourselves the 

 features of such a cataclysm seen close at hand ! 



It is quite impracticable to convey an adequate idea of the com- 

 plexity, strangeness, and beauty of these penumbral forms by an en- 

 graving ; and the description is likely to fail equally, both on account 

 of the unlikeness of the appearances to any thing with which we are 

 familiar, and the difficulty of using any descriptive terms which, drawn 

 from terrestrial analogies, will not here prove inaccurate. A plume- 

 like form, in the upper portion of the spot, is necessarily but an im- 

 perfect memorandum of an appearance, in reality all but impossible to 

 render with the pencil, even on a scale which depicted it a hundred 

 times this size. It might be likened to a sheet of glass, covered with 



