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Progress, Volume III, Issue 4, 1 February 1908, Page 123

formed without sufficient experimental basis for them, theory is sooner or later proved to be wrong. So Bacon's method (in which laws, principles, and theories are derived from experiment and observation, and, in which experiment alternates with theory and both mutually assist one another) is the one that is of real service in advancing scientific knowledge ; and for this reason it now reigns supreme in all branches of scientific enquiry and discovery. As indicated by splendid achievement, the most rapid and the most perfect development of the method is exhibited in the work of the late Lord Kelvin. In the teaching of scientific laws and principles, this method until comparatively recently had not been applied to any extent, and it results from this fact that practical men still sneeringly refer to " academic " knowledge and teaching. But of late the tendency in teaching science is more and

Fig. 1 shows an apparatus for studying the laws of motion of bodies falling freely under gravity. Observations are made on the body with regard to distances fallen through and corresponding times, not while the motion is taking place, but afterwards, on the permanent and complete time and space record of the motion which the apparatus gives. P is a polished brass plate (about 10 inches long) that is arranged to fall vertically, against almost negligible friction, by means of the side guide wires that can be tightened when required by the milled nuts, N. Y. is a vibrator making 60 double oscillations per second, and, which, at its free top end, carries a bristle that presses very lightly on the plate. The "give" of the wires allows the plate to be removed for the purpose of blackening it over a gas flame. When the plate is blackened it is suspended near the top