glass near him was cracked at the moment when he felt the shock, not when he heard the report, which was a little later. This shows that the earth-wave moved faster than the air-wave which produced the sound. There is also reason to believe that this earth-wave traveled much farther than the air-wave. A self-recording barometer in the laboratory of Lake Forest University, about thirty miles distant from Brighton village, showed a sudden movement of the mercury at about that time, which could be accounted for only by referring it to the wave of the explosion. Probably this was not the limit of the movement. Unfortunately, there were no means of determining the rate at which this earth-wave moved. All these conditions combine to surround this remarkable explosion with peculiar interest.
THE Association of German Naturalists and Physicians, which is so numerously and brilliantly represented here, having sixty years ago raised the banner of free investigation in our fatherland, has since, by its meetings, held from place to place, made the sciences, which had been previously pursued only in the narrow circle of experts, accessible to the life of the public, and therefore serviceable. The step was one fruitful in results. With it began a new age for mankind, which we have a right to call the scientific age. Nature had, indeed, given to primitive man—only weakly equipped in bodily strength—mental power and the faculty of observation, as the strongest of all weapons, in aid of his struggle for existence, and had taught him something of the use of her forces, his growing knowledge of the suitable application of which early smoothed his way to a higher civilization; and the arts of the earlier ages could be developed in many fields to a height at which we may still wonder, and means could be afforded for the achievement of artistic results of a perfection which has not since been reached; but all this came about by the toilsome and often fallacious way of the accumulation of empirical, uncomprehended, and unconnected observations and experiments, or by a way which could only slowly lead to the development of higher degrees of civilization.
These stages in civilization, however, comprised only a narrowly limited circle of development, and constancy was wanting to them, for they were attached to the person, and perished with it. Hence we see that, in the course of time, many eras of local civilization have bloomed
- The same instrument clearly recorded the earthquake-movement of the evening of August 31st.
- An address delivered before the meeting of German Naturalists and Physicians, in Berlin, September 18, 1886. Translated for "The Popular Science Monthly."