ASTRONOMICAL PROGRESS IN 1900-1901. 



for seventy minutes. It was truly a message 

 from .Mars! but not from its inhabitants. The so- 

 called discovery of canals comes in the same 

 category. The* illustrations herewith, especially 

 the second, are the most accurate of the photo- 

 graphic delineations of the so-called canals that 

 have been made. Fig. 1 was taken by Prof. E. A. 

 Douglas, of the Lowell Observatory. Flagstaff, 

 Ari/.., Feb. 20, 1901 : power. ."><)(); exposure, thirty - 

 >ix minutes. Fig. 2 was taken by Prof. Lowell, 

 the director. June f>. 1901 : power, 371; exposure, 

 >ixteen minutes. Both show the north polar 

 .-now cap. No cause worth recording has been 

 assigned for the long ha ii like lines. They can 

 not he clouds, but the other markings may be. 

 I loth views show, as Prof. Lowell says, " the Mare 

 Acidalium. also the changes in the canals during 

 tin- interval." and also changes in the snow cap. 

 As regards the habitability of Mars, no one 

 doubts. It seems improbable, however, that of 

 all the eight planets, the Earth alone should be 

 tin- home of sentient beings. And the same may 

 IM- >aid of the planetary worlds that revolve 

 around the countless millions of other suns. 



Jupiter. The planet Jupiter affords many ex- 

 amples of the marvelous, proving true the trite 

 saying. " The astonished astronomer has nearly 

 outgrown his ability to be astonished.'' This 

 giant planet has lately been well situated for ob- 

 servation. l>eing on the meridian at midnight, and 

 has l>een the target for bombardment by the 

 telescope, spectroscope, and the photo-camera. 

 Abundant evidence appears that Jupiter, from its 

 immense si/e. has not yet emerged, as our world 

 has, from his liquidity by heat, being still a white- 

 hot world. One new feature lately observed is the 

 existence of faint lines, somewhat resembling the 



At this writing they have again appeared. No 

 cause has been suggested that bears the impress 

 of probability, but it affords another strong argu- 

 ment in favor of the hypothesis that Jupiter is 

 in a white-hot, semifluid condition. 



Another curious feature of Jupiter's disk is his 

 belts. Several are visible, even with small tele- 

 scopes, on each side of his equator, extending en- 

 tirely around the planet. They are probably 

 clouds, assuming the beltlike form by the rapidity 

 of his rotation, only 9^ 55m, coupled with his 

 giant size, 274,000 miles in circumference. 



The same stripes are easily seen on Saturn, and 

 with some difficulty on Uranus. Recently they 

 have been seen there with the great telescope at 

 the Naval Observatory. They therefore seem to 

 be a feature belonging exclusively to the f cut- 

 outer planets, as the four inner ones have none. 

 They are so conspicuous on Jupiter that he is 

 often called the striped planet. 



The librations of some of the shadows of 

 Jupiter's satellites, while transiting his disk, have, 

 ever since the invention of the telescope, attracted 

 much attention, and elicited not a little discus- 

 sion among astronomers. To deal intelligently 

 with the problem, more observations than it has 

 yet received are necessary. About three years 

 ago Mr. C. T. Whitmell predicted that Satellite 

 III, when Jupiter was in quadrature, if transit- 

 ing his disk equatorially, would be 6 times 

 broader at the phase limb than at the other, and 

 that its height would remain constant; but if the 

 transit was not equatorial, the change in breadth 

 would be less. Lately these predictions have been 

 verified by observation by Mr. S. Bolton and 

 others, whose results are in admirable agree- 

 ment. 



E VEKKE8 OBSERVATORY, WILLIAMS BAY, WISCONSIN. 



so-called canals on Mars, crossing at various 



angles one of his equatorial belts. No cause has 



is yet been assigned for their existence there and 



t elsewhere. In 18M. 1880, and 1890 small 



black spots mottled his surface, which gave rise 



theory that the phenomenon is periodic 



Prof. Schaeberle, of Lick Observatory, also drew 

 ittention about the same time to the strange be- 

 havior of the shadows not only of this, but also 

 of the other three. 



On June 30, 1902, the Earth as seen from Jupi- 

 ter will transit the Sun, as do Mercury and 



