THE NUMBER OF THE STARS.—In No. 114 of Popular Astronomy, Mr. Gavin J. Burns makes some calculations and deductions as to the number of stars in the entire sky from the various star catalogues and photometric durchmusterungs which have been published. On the assumption that, on the whole, the stars are evenly distributed, he deduces from the plates taken for the Greenwich zone of the Astrographic Chart that there are 38 stars brighter than the second magnitude, 13,421 brighter than the seventh, and 8,325,000 brighter than the fifteenth. The ratio of the total number of stars brighter than any one magnitude to the number brighter than the next magnitude fainter is fairly constant at about 3.4 until the tenth magnitude is reached, but beyond that there is a sudden drop to 1.9, which ratio continues down to magnitude 15. From this discussion there is strong presumptive evidence that the stars thin out as their distance from our system increases.