Scientific American Supplement, No. 794, March 21, 1891 by Various
page 113 of 146 (77%)
page 113 of 146 (77%)
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our streets, instead of performing its former function of turning day
into night and ruining our health; but as I am not at all sure of the engineering possibilities of such a scheme, I will leave its discovery to some other abler prophet than myself. (_To be continued_.) * * * * * ELECTRICAL LABORATORY FOR BEGINNERS. BY GEO. M. HOPKINS. It is only when theory and practice, study and experiment, go hand in hand that any true progress is made in the sciences. A head full of theory is of little value without practice, and although the student may apply himself with all his energies for years, his time will, to a great extent, have been spent in vain, unless he by experiment rivets the ideas he gains by his study. In the study of electricity, for example, let the student try to remember the position a magnetic needle will take when placed below or above a conductor carrying a current which flows in a known direction. Without experiment there are nine chances of forgetting to one of remembering; but let the student try the experiment, and he will ever afterward be able to determine the direction in which the current is |
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