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THE POPULAR SCIENCE MONTHLY. 



ed on our system of weights and measures, 

 providing.the basis of the present State law. 

 In 1848 it secured an appropriation for the 

 equipment of stations for the systematic ob- 

 servation 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 Insti- 

 tute for several years, and the collection of 

 weather data by the observers it has enlisted 

 was continued afterward. The Institute sug- 

 gested, 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 par- 

 ticipated, through its committee, in 1875, in 

 the inquiry concerning the present and future 

 water supply of Philadelphia. Its investiga- 

 tion, in 1878, of the efficiency of the dynamo- 

 electric 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 formu- 

 lated for the first time a number of the con- 

 ditions to be observed in the wiring of build- 

 ings 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 be- 

 lieve in such a person, who has the power to 

 make lions, and who employs them as mes- 

 sengers 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 per- 

 form a post-mortem to the dead. Death in 

 war is the only exception. One of the elder- 

 ly men takes a strip of bamboo, and, mak- 

 ing 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 Wun- 

 dale, 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 vitali- 

 ty 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 compar- 

 atively 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 matura- 

 tion 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 'pro- 

 tective nature of the shell inclosing the seed. 

 The primary condition to the preservation of 

 vitality in a seed is perfect ripeness. Un- 



