THE POPULAR SCIENCE MONTHLY.
22·4 for 1880, and having ranged from 23·7 to 24·9 in the three decades from 1841 to 1870, and averaged 23·4 during the whole period. The health of London, which was practically stationary during the thirty years ending with 1870, showed a marked improvement during the following ten years; and it may be estimated that at least 70,000 persons were living within registration in London at the end of the ten years who would have died had the mean death-rate of the preceding thirty years been maintained. Dividing the ten years into two periods of five years, the death-rate appears to have been considerably lower in the later than in the earlier period. These facts afford strong evidence of the efficacy of the sanitary efforts of late years in the face of the increasing density of the population, which has, of course, worked against them. This ascription of improvement to the effect of sanitary measures is justified by the fact, that the most marked decrease in mortality is in that from zymotic diseases. The average annual death-rate from fever fell from 0·92 per 1,000 during the first three decades of the forty years to ·37 per 1,000 in 1871-'80. The rate of infant mortality has not, however, diminished to a corresponding proportion with the mortality from other classes of diseases.
The Aquarides, or July Meteors.—M. Cruls has communicated a notice of the meteors which the earth meets between the 25th and 30th of July, called Aquarides, because they appear to radiate from a point near δ Aquarii, of which regular observations have only recently been made under favorable conditions. The possibility of the earth meeting at a point in its orbit one or more currents of asteroids is very admissible. Each of these currents might be defined by its proceeding from distinct centers of emanation which may be determined by the crossing of the trajectories; but, to give a character of certainty to the existence of these centers, the determination should rest upon the definition of an adequate number of trajectories. If the existence of a considerable number of radiant points should be verified by continued observations, the phenomena would lose the character which a few trains isolated and distributed after a certain manner in space would present, and would assume that of an intricacy of asteroidal currents, compelling the admission that the infinite multitude of corpuscles occupies an immense zone analogous to the zodiacal light, and possibly having a certain connection with it. M. Cruls believes without doubt that the zodiacal light extends beyond the orbit of the earth, at least in certain directions; while he was observing the meteors in July, he saw the zodiacal light at one o'clock in the morning distinctly projected upon the zenith, and extending toward the eastern horizon; the earth was at that moment within its limits. Three astronomers and three pupils participated in watching the meteors at Rio, from the 25th to the 30th of July. They counted 2,710 meteors, and estimated that five per cent of the whole number escaped observation. It was manifest to all the observers that ninety per cent of all the paths of the meteors intersected each other in the neighborhood of Fomalhaut. The horary means increased fast from the hours of evening till those of morning, and exhibited a remarkable incandescence near sunrise. This seems to indicate that the swarms of meteors move in an opposite direction to the earth; for in that case, the movement of the earth at sunrise being directed toward that point in the ecliptic which is on the meridian, the meteors would then enter the atmosphere under more favorable conditions of speed than at any other hour of the night.
Piseco Lake-Trout and T Lake Falls.—Piseco Lake, in the Adirondacks, formerly the fishing-grounds of the once famous Piseco Club, was noted in the earlier days of its frequentation for the wonderful catches of trout it afforded. According to the statement of the Rev. Henry L. Ziegenfuss, in "Forest and Stream," an average of less than six men fishing from the club-house at Walton Lodge, for an average of less than nine days annually, succeeded in capturing in nine years—1842 to 1850—more than three tons of trout. The largest trout ever taken from the lake which was called for distinction the "Emperor"—was caught on the 24th of June, 1842, and weighed twenty-six pounds and eight ounces. Another fish weighed twenty pounds and a quarter, and