P. 160.—Prof. W. H. Pickering observed some of the canals on Mars in 1890 with a 12-inch refractor, but was not able to double any of them. He says that, in examining these objects, the power employed should not “exceed one or two hundred.” This is quite contrary to the advice of others, who recommend high magnifiers; and perhaps it accounts for Prof. Pickering’s failure in recognizing the duple canals. With the great 36-inch refractor Mr. Keeler saw, on July 5 and 6, 1890, some curious white spots on the edges of the gibbous limb of Mars, something similar to those visible on the unilluminated part of the lunar disk. The canals were observed as feeble diffused bands. The two satellites were seen by a lady visitor, though previously unaware of their existence. P. 161.—The method of deriving the rotation-period of Mars is exemplified by Mr. Proctor in the ‘Monthly Notices,’ vol. xxviii. p. 38. An interesting paper, “On the Determination of the Rotation-Period of Jupiter in 1835,” will be found in the ‘Memoirs,’ vol. ix. PLANETOIDS. P. 167.—The 308th planetoid was discovered by Charlois on March 5, 1891. JUPITER. P. 170.—Dupret, in Algiers, saw Jupiter with the naked eye on Sept. 26, 1890, and following days, twenty minutes before sunset. P. 191.—M. Guillaume, during a recent transit of the shadow of Jupiter’s second satellite, observed a duplicate shadow, fainter than the ordinary one, which partly covered its southern side. COMETS. P. 250.—On Nov. 16, 1890, Dr. Spitaler, while looking for Zona’s Comet with the 27-inch refractor of the Vienna Observatory, discovered a new and very faint comet only 23′ distant from the object of his search. That two of these bodies should be found almost simultaneously and so near together must be regarded as a very singular coincidence. METEORS. P. 261.—Mr. Proctor held the view that certain meteorites may have originally been ejected from the Sun. A recent writer thus summarizes our knowledge of them:—“That they are independent bodies, moving in orbits of their own in space; that these dark bodies are abundant in the interplanetary spaces; that those within the near range of solar or planetary attraction move with great velocity; that many swarms of them follow well-known orbits; and that, in general, their origin is undoubtedly the same as that of other celestial bodies” (‘Sidereal Messenger,’ June 1890, p. 284).