Page:Popular Science Monthly Volume 59.djvu/425

Rh In Europe, soon after the discovery of its variability, its range was said to be two magnitudes, that is, it shone with about six times more light at maximum than at minimum. Precise photometric measurements of the light of Eros, made by Professor Wendell, on March 12 of the present year gave a range of variation of 1.1 magnitudes and on April 12, of 0.4 of a magnitude. On May 6 and 7 no variation was perceptible, and it was less, probably, than a tenth of a magnitude. Owing to poor weather and the planet's approach to the sun, later observations have been difficult. But a slight variation was apparent in June. These unique phenomena probably are the result of the changing direction of the axis of rotation referred to the line of sight. Although the direction of this axis in space is fixed, it will constantly change with reference to an observer on the earth. When the axis, if ever, points directly towards the earth, there can be no variation of light, and the maximum range mil be found when the axis is perpendicular to the line of sight. Apparently this axis has recently been pointing towards the earth. We may confidently expect that within a short time Eros will again show well marked changes, although the planet's position may not permit exact observations. On March 5, M. Ch. André communicated to the 'Astron. Nach.' a discussion, in which he assumed that the variation is due to the fact that Eros is a double asteroid. M. Andre even gave approximate elements for a system which appeared to him to satisfy the conditions. Professor Pickering has recently pointed out. that the variations in light can hardly be accounted for by two similar bodies alternately eclipsing each other, and has suggested that the known facts can be explained by the rotation either upon an elongated, cigar-shaped body, or of a body, one side of which is much darker than the other. The solution of the interesting problems, which Eros presents, may not be possible until the next opposition, which does not occur for about two years. Eros will be in conjunction with the sun in the spring of 1902, and in opposition in the summer of 1903. The distance of the planet at that time will be great, since Eros will not be at perihelion, but this will not prevent precise determinations of the changes in light, with a telescope of sufficient I power. At the next opposition, however, the path of Eros will be in the southern sky. The most favorable time for observation will be from March to August, 1903. During these months its declination will be between 30° and 45° south of the equator, which will make it difficult or impossible of observation at northern observatories.

the death of Professor Joseph Le Conte, America has lost the man of science who was most honored and beloved. An age of extreme specialization and keen competition can still appreciate the general culture and broad survey of nature which make a great teacher and a great man. Other contemporary men of science have more exact knowledge of a limited field and have made more definite contributions i to science, but there is perhaps no one who has done such good work in such diverse directions or whose influence, has been so wide and beneficent. Le Conte was descended from a Huguenot family, driven to America after the revocation of the edict of Nantes. His father, uncle and brother were all emiment in science. Born in the South in 1828, he began to practise medicine, but his love of natural science led him to go to Harvard to work under Agassiz. He held chairs in southern universities, but these being disabled by the civil war, he accepted a call to the University of California before its opening, and for thirty-two years has been professor of geology and natural history and the leading scientific man on the Pacific coast. His teaching and