THE POPULAR SCIENCE MONTHLY. 



began a study of natural history by the col- 

 lection of eggs. Mr. Milne Redhead did not 

 think the act of bird-nesting the greatest 

 evil, but the collection of eggs for sale in 

 large towns. Prof. Newton spoke of the 

 practical impossibility of convicting bird- 

 nesters on account of the difficulty of distin- 

 guishing between the eggs of one species and 

 those of another. 



Various Speeds. The horse, said Mr. 

 Jeremiah Head, in a paper recently read, 

 though he could not walk faster than man, nor 

 exceed him in jumping heights or distances, 

 could certainly beat him altogether when gal- 

 loping or trotting. A mile had been galloped 

 in one hundred and three seconds, equal to 

 thirty-five miles per hour, and had been trotted 

 in one hundred and twenty -four seconds, equal 

 to twenty-nine miles per hour. How man's 

 position as a competitor with other animals 

 in speed was affected by his use of mechan- 

 ical aids, but without any extraneous motive 

 power, was considered in reference to loco- 

 motion on land, in water, and in air. But 

 the most wonderful increase in the locomo- 

 tive power of man on land was obtained by 

 the use of the modern cycle. One mile had 

 been cycled at the rate of 27'1 miles per 

 hour, fifty at twenty, one hundred at 16'6, 

 three hundred and eighty-eight at 12'5, and 

 nine hundred at 12 '43 miles per hour. Un- 

 aided by mechanism man had shown himself 

 able to swim for short distances at the rate 

 of three, and long distances (twenty-two 

 miles) at the rate of one mile per hour. He 

 had also given instances of being able to re- 

 main under water for four and a half min- 

 utes. Credible eye-witnesses stated that 

 porpoises easily overtook and kept pace with 

 a steamer going twelve and a half knots, or, 

 say, over fourteen miles an hour, for an in- 

 definite length of time. This was five and 

 fifteen times the maximum swimming speed 

 of a man for short and long, distances re- 

 spectively. 



Tendencies of Population. In a paper 

 read in the British Association, Mr. E. Can- 

 nan, of Oxford, sought to show that, con- 

 trary to the general belief that the population 

 of the great towns is being increased almost 

 as much by immigration as by excess of 

 births over deaths, the excess of immigrants 



over emigrants, or net immigration, is rapidlv 

 diminishing, and seems likely to disappear 

 before the end of the century. The net im- 

 migration into London in the last ten years 

 was only fifty-six per cent of what it was in 

 the previous ten years, and only sixty-three 

 per cent of what it was thirty years before, 

 when the population was two and a half mil- 

 lions less than it is now. In this matter Lon- 

 don is by no means in advance of the other 

 great towns. In Liverpool the net immigra- 

 tion was 68,000 in 1851 to 1860, 56,000 in 

 1861 to 1870, 49,000 in 1871 to 1880, but in 

 1881 to 1890 the balance was the other way, 

 and there was a net emigration of 15,000. 

 In the case of Manchester the decline of the 

 net immigration was neither so continuous 

 nor so great as in Liverpool, but it was con- 

 siderable. In each of the first two decades 

 it was about 32,000, then it rose to nearly 

 50,000, but in the last decade it has declined 

 to 17,700. The three great Yorkshire towns, 

 Leeds, Sheffield, and Bradford, showed con- 

 siderable fluctuations. Into the three taken 

 together the net immigration was 25,000 in 

 1851 to 1860; in 1861 to 1870 it made an 

 enormous jump up to 78,000, and then 

 dropped right down to 18,000 in 1881 to 

 1890. The net immigration into the towns 

 was affected by migration between the towns 

 and other countries as well as by migration 

 between the towns and the rest of England 

 and Wales. 



Animal and Artificial Mechanism. 



Comparing animal mechanism with artificial, 

 Mr. Jeremiah Head said, in his sectional ad- 

 dress at the British Association, that all ani- 

 mals were in their bodily frames, and in the 

 intricate processes and functions which went 

 ou continuously therein, mechanisms of so 

 elaborate a kind that we could only look and 

 wonder and strive to imitate them a little here 

 and there. The mechanical nomenclature of 

 all languages was largely derived from the 

 bodies of men and other animals. Many of 

 our principal mechanical devices had pre- 

 existed in them. Mr. Head proceeded to 

 consider how far man was in his natural con- 

 dition, and had become by the aid of mechan- 

 ical science, able to compete successfully with 

 other and specially endowed animals, each in 

 tiis own sphere of action. The bodily frame 

 of man was adapted for life and movement 



