Page:Popular Science Monthly Volume 40.djvu/591

Rh speed of traveling the motion became intolerable, and, when a high rate of speed was reached, few people could keep their seats. By degrees, but very slowly, these things were improved. Better ventilation was insured, more wheels were added, and the carriages were enlarged; doors and windows were so constructed as to keep out the clouds of dust that choked the traveler on badly made and ill-kept lines. The same principle of evolution which has turned the old stage-coach into the comfortable saloon carriage has been at work in every department of railways and their management, and the highly intricate and important system of modern signaling springs from a most simple beginning. Shortly after the opening of the Stockton and Darlington line, which was the earliest line constructed, one of the station-masters is traditionally said to have adopted the simple expedient of putting a lighted candle in the window of the station-house when it was necessary for the train to stop. When the Liverpool and Manchester Railway was first opened, in 1830, the only means of signaling the trains was a flag by day and a lamp by night. The first advance to modern signaling began about four years after the line had been opened, when stout posts were provided upon which lamps were placed by the points-man. Nowadays the signalman's cabin is the center from which all signaling radiates.

Rainfall by Explosion.—Reviewing the theories of artificial rain-making. Prof. E. J. Houston draws the general conclusions, in view of the present state of meteorological science, that rain can never be made to fall at will by mid-air explosions on any part of the earth's surface, irrespective of the climatic conditions there existing; but during certain meteorological conditions, mid-air explosions may result in rainfall over extended areas; that the liberation of energy necessary for such rainfalls is due not to the midair explosions, but to the energy stored up in the moist air from which the rain is derived; that the meteorological conditions which must exist for the successful action of mid-air explosions would probably in most though not in all cases themselves result in a natural production of rain; that a comparatively high difference of electric potential between different parts of the air, or between the air and the earth, is possibly favorable, when taken in connection with other meteorological conditions, for artificial rain-making; and that an undirected mid-air explosion is not as likely to produce rain as an explosion in which the main tendency of the energy liberated is to cause a general uprush of the air. Among the "certain meteorological conditions" mentioned in this summary is that in which the air is in a state of very unstable equilibrium, when a slight determining cause may result in the liberation of the stored-up energy, with a resulting heavy rainfall. In such cases it may appear that there are no reasons why an explosion in mid-air should not be followed by rain. In this case rain might be eventually caused without artificial aid. A condition in which heavy rains might be artificially produced by mid-air disturbances, when without them there would be none, may exist when a layer of warm, moist air exists between the earth's surface and a higher layer of cold, moist air, separated by a comparatively thin layer of air, and other conditions are such as to maintain the two layers separate. The breaking or piercing of the intermediate separating layer might then permit such an uprush of the warmer air as would result in the formation of a true storm center and a heavy rainfall.

Weddings among the Shushwap Indians.—Dr. Franz Boaz, in his report to the Hon. Horatio Hale for the British Association concerning the northwestern Indian tribes of Canada, describes from native accounts the marriage ceremonies of the Shushwap as follows: "A young man who wishes to marry a girl takes a number of horses and other property that is considered valuable, and offers it to the father of the girl he wishes to marry. The latter, before accepting the price offered, invites his whole family to a council and asks their consent. If they agree to accept the suitor, and the price he has offered for the girl is satisfactory, they tie the horses to their stable and take the other goods into the house, as a sign of their willingness. After this the young man may take the girl without further ceremonies. After the marriage the bridegroom and his family go on a hunting expedition, and try to obtain