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Page:Popular Science Monthly Volume 18.djvu/229

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ponds to the wind-disturbed waters of the bays. Those fresh-water fishes that do not wander away, go to the well-aired spots in their neighborhood to spawn—to the shore-waters, the wet meadows, or the junctions of rivers, or to the tributary streams of the lakes in which they live. Those salt-water fish which live at the bottom likewise go to the waters near the shores, where the flats and the meadows swarm during the spring with their young. The eggs of the cod and mackerel are buoyed upon the surface of the water, where the winds blow constantly over them. The stickleback will swim before its nest and fan it with its pectoral fins by the hour. Thus every fish illustrates in some way the law that a constant change of air is essential to the development of its eggs. Agitated and sun-lighted waters are also most favorable to the larvæ of crustaceans and mollusks, of echini and polyps, and to the microscopic creatures of which the food of the fry chiefly consists, and thus fulfill another condition of the most vigorous growth of the young fish.—Translated and abridged from Die Natur.




THE situations in which a motor of comparatively small power can be used with advantage, and in which it is a necessity even, are already very numerous and are constantly increasing. Not only has it a proper place in the workshop, in the business house, and on the farm, but in the household as well it has a wide range of utility. The need for such a machine in our homes, created by the sewing-machine, has been strengthened and increased by various other appliances in use or coming into use, while such devices as fans for cooling rooms in summer and ventilating them in winter further add to the requirement. In suburban and country residences, and on the farm, the primary need is for pumping water, and this alone renders a light and economical power almost indispensable. For the performance of most of the other mechanical operations upon the latter it is also of the utmost value. In the field of small industries the uses to which such a motor can be turned are as numerous as the varied occupations of the workers. The necessities of numbers of amateurs further increase the range of activity for such a power. The kind of machine that is suitable to the varied needs of these different classes of users necessarily differs in each. In most trades the demand for power is for one of from two to five horse and above, and on the farm a serviceable machine could not generally be much if any less; but in the