ASTRONOMICAL PEOGRESS AND PHENOMENA. 



49 



them that met with general acceptance have, 

 until recently, been promulgated. For several 

 years past, Prof. S. P. Langley, director of the 

 observatory at Allegheny, Pa., has been as- 

 siduously engaged in the study of solar phys- 

 ics, and, with a new and ingenious instrument 

 of his own invention, called a bolometer, has 

 contributed to science many valuable facts, 

 some of which entirely controvert theories 

 that were considered invulnerable The results 

 of his investigations have lately been published 

 in vol. xv of the "United States Signal-Serv- 

 ice Reports." From observations at the Al- 

 legheny Observatory, and on Mount Whitney, 

 he made the solar constant 2 - 84 calories, which 

 heretofore was considered much less. In 

 1878, from the summit of Pike's Peak, during 

 the total eclipse of that year, he investigated 

 the solar spectrum, and proved that the rays 

 of the " great group A " were double. He has 

 shown, also, by the bolometer, that the sun's 

 heat lias been underestimated by 50 per cent. 

 This wonderfully delicate and sensitive instru- 

 ment has enabled him to measure with precis- 

 ion the undulations of long wave-lengths be- 

 low the visible red, to the extent of forty times 

 as great as was known to other solar physi- 

 cists; and it promises, in his hands, to add 

 much more to our knowledge of the sun and 

 his immediate surroundings. 



Eclipses. In the year 1886 there were two 

 eclipses ; and, as is always the case under such 

 circumstances, both were of the sun. The 

 first, occurring on March 5, was annular, and, 

 except across the southern portion of Mexico, 

 its annular phase was in a path wholly oceanic. 

 No effort was made by astronomers to observe 

 it, as such eclipses are nearly barren of valu- 

 able results. Now, however, in view of the 

 fact that Dr. Huggins is quite certain of his 

 success in photographing the solar corona in 

 presence of an uneclipsed sun, and that he 

 would be doubly assured were he permitted to 

 try his experiment when all but its circumfer- 

 ential portion was hidden by the moon, future 

 eclipses of this character must have a value of 

 their own. The second eclipse, which took 

 place on Aug. 28 and 29, was total, and, in re- 

 spect to duration of totality, was one of the 

 most remarkable of modern times, though, un- 

 fortunately, like its predecessor, its path of to- 

 tal eclipse, except near the beginning and end- 

 ing, was entirely on the ocean. The island of 

 Grenada, in the Caribbean Sea, and one or two 

 other small islands adjacent, were the only 

 places in this hemisphere for observing it to 

 advantage. No efforts were made by Ameri- 

 can astronomers to secure observations of this 

 rare phenomenon, though the islands were oc- 

 cupied by several parties from Europe. At 

 most of these stations the sky was clear, and 

 important results were achieved, a brief sum- 

 mary of which is subjoined, though, being un- 

 official, it may require modification. Prof. 

 Tecchini, during totality, observed the promi- 

 nences with a 6-inch telescope. After to- 

 VOL. xxvi. 4 A 



tality, he reobserved them with the spectro- 

 scope, and found, to his surprise, that, seen 

 under these two different conditions, and by 

 such different methods, they were not the 

 same. Hence we conclude that a spectroscopic 

 observation of an uneclipsed sun reveals only 

 a part of what is seen with a telescope during 

 an eclipse. This is an important addition to 

 our knowledge of these enormous clouds that 

 are seen during all eclipses floating in the 

 sun's atmosphere, sometimes to a height almost 

 equaling the moon's distance from the earth. 

 About twenty photographs of the corona were 

 secured, on five of which the chromosphere is 

 depicted. The famous line 1474 was seen two 

 minutes before totality. At the close of last 

 year's report, on ' Astronomical Progress and 

 Phenomena," no news had been received from 

 the observing parties that went to New Zea- 

 land to observe the total eclipse of Sept. 9, 

 1885. From published reports it does not ap- 

 pear that that eclipse added much to what 

 was already known. The serrated appearance 

 of the corona was, as in other eclipses, a dis- 

 tinctive feature and easily observable. Shortly 

 before totality the rare phenomenon of the 

 projection of the moon's contour on the back- 

 ground of the bright corona was seen. 



Naked-Eye View of the Corona. Mr. Ford hav- 

 ing made the improbable statement that the 

 sun's corona could, in a clear sky, and without 

 an eclipse, be distinctly seen from the top of 

 a high mountain with the naked eye, Sig. F. 

 Tecchini, successor of Secchi, at the observa- 

 tory of the Collegio Romano, has published a 

 confirmation of the strange announcement. 

 From the summit of Mount Etna, on two differ- 

 ent days, he observed the phenomenon, which 

 presented the appearance of a white ring, sur- 

 rounded by a splendid copper-red corona. 

 Probably the spectacle witnessed by both ob- 

 servers was " Bishop's ring," a supposed ac- 

 companiment of the recent sky-glow which, at 

 the time, was visible even from the surface of 

 the earth. 



Snn-Spots and the Weather. The influence of 

 the spots on the solar surface upon the weather 

 of our planet still continues to agitate the pop- 

 ular mind. Ever since the invention of the 

 thermometer it has been proved that the an- 

 nual amount of heat that the earth as a whole 

 receives is a constant quantity, and that it is 

 undeviatingly the same through the periods of 

 sun-spot maxima and minima. Jelenck, of 

 Prague, has tabulated all the observations he 

 could collect in Germany, extending over one 

 hundred years, and after a complete discussion 

 of them has come to the conclusion that there 

 is no correspondence whatever between sun- 

 spots and the weather. Some enthusiasts have 

 even gone so far as to connect these spots with 

 cyclones, rainfalls, financial crises, epidemics, 

 the price of grain, etc. This, though fine theo- 

 rizing, is not science. 



Minor Plants or Asteroids. Since vol. x of the 

 " Annual Cyclopascfta " went to press, fourteen 



