Page:Popular Science Monthly Volume 47.djvu/880

862 on our system of weights and measures, providing.the basis of the present State law. In 1843 it secured an appropriation for the equipment of stations for the systematic observation and collection of meteorological facts—probably the earliest instance in this country of such an appropriation. This work was begun, extended, and carried on under the direction of the committee of the Institute for several years, and the collection of weather data by the observers it has enlisted was continued afterward. The Institute suggested, in 1887, the institution of the present State weather service. In 1864 it obtained a report on the shape and proportions of screw threads used in machine construction, which gave the basis for the standard now universally current in this country. It participated, through its committee, in 1875, in the inquiry concerning the present and future water supply of Philadelphia. Its investigation, in 1878, of the efficiency of the dynamoelectric machine for arc lighting appears to have been the earliest intelligent inquiry into the relative merits of the several types of these machines. In 1884 a more elaborate report was issued on the same subject, and another on the Life-Duration and Efficiency of Incandescent Electric Lamps. Allied to these investigations was its report on The Conditions of Safety in Electric Lighting, published in December, 1881, which formulated for the first time a number of the conditions to be observed in the wiring of buildings and the running of circuits, which have since become incorporated in the regulations of the Fire Underwriters' Association.

North Nyassa Superstitions.—Connected with the superstitions of the people of the region north of Lake Nyassa, in Africa, are the sacred groves or burial places of their ancestors. The undergrowth in them is so thick that the sun's rays seldom penetrate. In their days of trouble the priests resort there to pray to the spirits of their fathers. In them the prophets deliver their messages. No other living creature is allowed to enter. Should war or disease visit the tribe, the priest kills a bull, and offers the blood and the head of the animal. The people firmly believe in the spirit of evil. He is "Mbasi." In one place Mbasi is a person—an old man—who exercises extraordinary power. He speaks only at night, and to the head men of the tribe, and during the interview every other voice must be silent and.every light extinguished. In Wundale the people believe in such a person, who has the power to make lions, and who employs them as messengers of evil. His house is surrounded with long grass, in which he keeps his lions, as other men keep dogs. If a man has a dispute with a neighbor who refuses to come to terms, these lions may be hired to destroy his cattle. Dr. D. Kerr-Cross was much struck to find that all over the north end of Lake Nyassa the people regularly perform a post-mortem to the dead. Death in war is the only exception. One of the elderly men takes a strip of bamboo, and, making an incision in the abdominal wall below the ribs, carefully inspects the viscera. They bury immediately outside the door of the house, and in a sitting posture. In Wundale, about a year after the decease, and at dead of night, the friends lift the bones and cast them into certain clumps of trees found all over the country. These groves are full of human bones.

The Vitality of Seeds.—Discussing the vitality of seeds, Mr. W. Botting Hemsley first speaks of the infinity of variety in the behavior of seeds under different conditions. Neither under natural nor under artificial conditions will some seeds retain their vitality more than one season. Others will hold their life for a time that has not yet been defined. The scarlet-runner bean loses its germinative power on exposure to comparatively slight frost, the degree depending upon the amount of moisture in it; yet it will retain its vitality for an almost indefinite period under favorable artificial conditions In both this seed and the acorn germination would naturally follow as soon after maturation as the conditions allowed. The seeds of the hawthorn are incased in a hard, bony envelope, in addition to the proper coat or testa. Committed to the earth, and under the most favorable conditions, these seeds do not germinate till the second year, and often not so soon. Prolongation of vitality is probably due in some measure to the 'protective nature of the shell inclosing the seed. The primary condition to the preservation of vitality in a seed is perfect ripeness.