8 14 THE POPULAR SCIENCE MONTHLY. 



glass near him was cracked at the moment when he felt the shock, not 

 ■when he beard 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 move- 

 ment. Unfortunately, there were no means of determining the rate 

 at which this earth-wave moved. All these conditions combine to sur- 

 round this remarkable explosion with peculiar interest. 



THE SCIENTIFIC AGE.f 



By Db. WERNER SIEMENS. 



T ] 



1HE 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 ap- 

 plication 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 fal- 

 lacious 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. 



t An address delivered before the meeting of German Naturalists and Fhysicians, in 

 Berlin, September 18, 1886. Translated for " The Popular Science Monthly." 



