4H 



THE POPULAR SCIENCE MONTHLY. 



22-4 for 1880, and having ranged from 23 - 7 

 to 24*9 in the three decades from 1841 to 

 18*70, 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 im- 

 provement 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 sani- 

 tary 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 mortal- 

 ity is in that from zymotic diseases. The 

 average annual death-rate from fever fell 

 from 092 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 corre- 

 sponding 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, be- 

 cause they appear to radiate from a point 

 near 5 Aquarii, of which regular observa- 

 tions 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 admis- 

 sible. Each of these currents mirfit be de- 

 fined 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 con- 

 siderable 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 oc- 

 cupies an immense zone analogous to the 

 zodiacal light, and possibly having a certain 

 connection with it. M. Cruls believes with- 

 out 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 distinct- 

 ly 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 observa- 

 tion. It was manifest to all the observers 

 that ninety per cent of all the paths of the 

 meteors intersected each other in the neigh- 

 borhood of Fomalhaut. The horary means 

 increased fast from the hours of evening till 

 those of morning, and exhibited a remarka- 

 ble 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 atmos- 

 phere 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 Pi- 

 seco Club, was noted in the earlier days of 

 its frequentation for the wonderful catches 

 of trout it afforded. According to the state- 

 ment of the Rev. Ilenry 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 



