_Occultations of Stars._—Among the various phenomena to which the lunar motions give rise none are more pleasing to the possessors of small telescopes than occultations of stars. Several of these occurrences are visible every month. If the amateur has the means of obtaining accurate time, he will engage himself usefully in noting the moments of disappearance and reappearance of the stars occulted. This work is efficiently done, it is true, at some of our observatories, and therefore little _real_ necessity exists for amateurs to embark in routine work which can be conveniently undertaken at establishments where they have better appliances and trained observers to use them. The mere watching of an occultation, apart from the registry of exact results, is interesting; and there are features connected with it which have proved exceedingly difficult to account for. The stars do not always disappear instantaneously. On coming up to the edge of the Moon they have not been suddenly blotted out, but have appeared to hang on the Moon’s limb for several seconds. This must arise from an optical illusion, from the action of a lunar atmosphere, or the stars must be observed through fissures on the Moon’s edge. The former explanation is probably correct; for it has happened that two observers at the same place have received different impressions of the phenomenon. One has seen the star apparently projected on the Moon’s limb for about 5 seconds, while the other has witnessed its sudden extinction, in the usual manner, as it met the Moon’s edge. New observations, made with good instruments and reliable eyes, and fully described, will doubtless throw more light on the peculiar effects sometimes recorded. _Visibility of the new and old Moon._—It is an interesting feature of observation to note how soon after conjunction the Moon’s thin crescent is observable with the naked eye. A case has been mentioned in which the old Moon was seen one morning before sunrise and the new Moon just after sunset on the next day. At Bristol, on the evening of March 30, 1881, I saw the new Moon at 7^h 10^m, the horizon being very clear in the west. She was then only 20^h 38^m old. On June 4, 1875, I observed the Moon’s crescent at 9^h 10^m, or 22^h 49^m after new Moon. Dr. Degroupet, of Belgium, saw the old Moon on the morning of Nov. 22, 1889, between 6^h 47^m and 7^h 22^m G.M.T., or within 18^h 22^m of the time of new Moon. FOOTNOTES: [16] In September 1889 Prof. Thury, of Geneva, reported a change in the centre of the crater Plinius. With a 6-inch refractor he saw, instead of the usual two hills in the interior, a circular chalk-like disk “with a dark spot in its centre like the orifice of a mud-volcano.” [17] A fine ring-plain, 25½ miles in diameter. [18] Mädler says “the full Moon knows no Maginus,” meaning that this object is invisible under a vertical Sun.