18 KANSAS CITY REVIEW OF SCIENCE. 



termed "bridges" of fire. But these bridges did not maintain the same position 

 an hour. They were widening, contracting, or bending into ever-changing 

 forms. They were white-hot; that is, whiter than the solar disc, — presumably 

 hotter. One could not see them move any more than the hour-hand of a clock 

 can be seen in motion, but on returning to the telescope after an interval of half 

 an hour, displacement could be detected. At 9 A. M. two tongues of fire were 

 pointing toward each other from opposite sides of the abyss, and at 12:30 P. M. 

 P. M. passed, leaving quite a space between. Shortly after they began a curva- 

 ture, which, at 2 P. M., formed a circle, clearly a case of solar cyclone. 



A sun-spot is composed of two portions, the umbra and penumbra. The 

 umbra is the dark central portion, while the penumbra or border is many shades 

 lighter, yet, much darker than the disc of the sun. The penumbral fringe 

 looks like a down-rush of matter into or upon the umbra ; its sides are 

 inclined, and are striated throughout, the strige having the appearance of 

 willow leaves laid on the inchne, parallel to one another, their small 

 ends projecting over the back umbra, giving the edge of the penumbra 

 a serrated form, Uke saw-teeth. When many of these projections join 

 and receive an impulse, they pass entirely across the umbra, forming 

 an incandescent bridge. And Sunday every large spot had bridges complete 

 or in the process of formation. In the large cliasm, at about 4:30 in the after- 

 noon, one of the bridges split lengthwise, the separation requiring more than two 

 hours, while the ends of several jets were tufted and tasseled with filaments of 

 white hot matter, which coinciding near the center of one of the largest divisions, 

 presented the appearance of the whirlpool rapids below Niagara, should that frenzy 

 of water be instantly rendered motionless. We have no spectroscope, but with 

 one of good dispersion we should have been able without doubt to behold move- 

 ment in the troubled mass ; or, at all events, the displacement of hydrogen lines in 

 the spectrum of the seething vortex. Neither have we a micrometer ; hence were 

 not able to arrive, at accurate measurement. But the results above, 67,000 miles 

 in length and 48,000 miles in breadth, are within 2,000 miles of the truth. The 

 width given is that at the maximum point ; the spot, contracting somewhat toward 

 the solar equator, gives it the shape of a rude triangle. Calculating its area, we 

 found that thirty worlds like the earth, side by side, could plunge at once into 

 the mighty gulf and be destroyed in a moment. Measurement was made by 

 time of transit of longest diameter of spot over central wire in eye-piece, the time 

 being ten seconds. But one second of time of the earth's rotation equals fifteen 

 seconds of arc, celestial space. One second of space on the sun is 450 miles, 

 and the diameter of the spot being 15,000 seconds arc, made 67,500 miles. Several 

 spots beside had diameters of from 5,000 to 10,000 miles, which, forming centers 

 of clusters, gave the solar disc an impressive aspect. There were three faculse 

 also on the sun — brilliant spaces much brighter than the general surface. The 

 terrestrial atmosphere being in fine condition for telescopic manipulation, the 

 " rice-grains, " granulations and pores all over the sun could be distinctly seen. 

 Altogether the day was one of moment in the means offered of studying solar 



