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Rh in this Institution in 1855, and who has taken a warm interest in the success of the present course. I put a weight on the scale-pan below the lever and irritate the muscle. Observe it can lift, as you hear by the tone of the bell, 5, 10, 20, 30, 40, 50, 100, 200, 250, 300, 350, 400, even up to 500 grammes. It can

actually, by a sheer pull, move a mass one thousand times its own weight. Is not this a wonderful expenditure of mechanical energy?