Page:Popular Science Monthly Volume 28.djvu/148

140 Then (In my dream) I dreamt that he tried to frighten me, and make believe he was a ghost, by pushing me down sideways, etc. After that I waked and heard no more." We fancy ghosts as impalpable beings, clothed ill white. Blind men can hardly have as distinct an imagination of their appearance.

A Workmen's Scientific Class.—How knowledge may be disseminated by means of local lectures to working-men is illustrated in a story told by Mr. Roberts, of Cambridge. Two miners, at Buckworth, England, walked four or five miles and back m the evening, after work, to attend the course at Cramlington. Finding others in their village wanting to know something of chemistry, but not able to attend the course, they took to repeating to a class of seven on the next evening the lectures they had heard, and, having supplied themselves with chemicals, repeated the experiments. Mr. Roberts attended one of the meetings of this class at the end of the term, examined the members, and found that they had acquired a sound enough knowledge of the subject to pass the regular university examination. The class were this summer to carry on in the same manner a course in physiology, in aid of which they were endeavoring to procure a microscope.

Mechanical Science at the American Association—The vice-presidential address of Professor J. Burkitt Webb, in the Section of Mechanical Science, was on "The Second Law of Thermo-dynamics," but was too technical for abstract in these pages. Mr. L. S. Randolph gave an account of his experiments in seeking for an explanation of the peculiar manner in which the stay bolts between the fire-box and the boiler shell of steam-boilers had been found to break. He indicated a drawing and bending of the bolts occasioned by the shifting of the plates under changes of temperature as the cause, aided by the corrosive action of the water that might reach the bolts. Mr. Stephen S. Haight presented a paper on the use and value of accurate standards for surveyors' chains. He exhibited a specimen chain of flattened steel wire, with thermometer attached to record temperature, a spring-balance to weigh the tension, and a spirit-level. Professor Davis exhibited a tape which he had found accurate enough for general use in a large range of work in Michigan. Professor J. B. Webb read a paper on the lathe as an instrument of precision, in which he called attention to the desirability of greater accuracy in instruments of this class, and described some simple methods for making tests of the degree of error in any particular instrument. Professor Cooley explained a new smoke-burning device. A committee report was presented and a discussion had on the best methods of teaching mechanical engineering. The object of the instruction being admitted to be thorough preparation in theory and principle, Professor Thurston said that the training should be adapted to the work to be done, and that he therefore favored classification into manual training-schools, schools of mechanic arts, and schools of engineering. It I was asserted by other speakers in the course of the discussion that there are no manual I training-schools where a boy can learn a trade before entering the higher schools; and that the St. Louis and Chicago manual training-schools will not make workmen, and probably not five per cent of their students will ever become workmen.

Science In Common Schools.—The committee of the American Association on methods of science-teaching in the schools stated that much had been accomplished in the investigation, in which many associations, schools, and persons had interested themselves. The committee of conference with foreign associations in reference to an international convention of science associations had conducted an extensive correspondence, and the subject was to be brought before the British Association at Aberdeen. An endowment fund of twenty-five thousand dollars had been given to the scheme by Mrs. Elizabeth Thompson, of Stamford, Connecticut. The committee was continued as I the "Committee on International Scientific Congress." The committee on the encouragement of researches upon the health and diseases of plants reported that at its suggestion the Commissioner of Agriculture had appointed Mr. F. L. Scribner, of Girard College, Philadelphia, to take charge of a