BEYOND THE LIMITS OF VISION; 



Or, The World Below the Microscope.* 



Midway between two infinities lies the world that is revealed 

 to our senses. A wide and wonderful world it seems to us, for 

 within its range are all the forms and phenomena which are at 

 the foundation of our knowledge, the arts and the sciences. 

 Yet marvelous and almost infinite as are the scenes and objects 

 unfolded to our sight, they form but an infinitesimal part of the 

 boundless range of nature both beneath and beyond the limits of 

 our perceptions. 



The sharpest eyes, under .the most favorable circumstances for 

 observation, can see only about five thousand stars in all the 

 sweep of the heavens. With the highest powers of the telescope 

 it is estimated that twenty million stars are visible. Yet all 

 these are only the brightest or the nearest of the suns which 

 compose the great cluster of the Galaxy or Milky-way, to which 

 system our sun belongs. In many parts of the Miljky-way even 

 the giant reflector of Lord Rosse discloses, beyond the stars which 

 it resolves, only the same milky whiteness which we see every 

 clear night in that marvelous girdle of the heavens. We have 

 not yet seen even all the outlying lights of our own City of the 

 skies. Yet this immense aggregation of worlds composing the 

 Milky-way, numbering, with the dark planets which are doubt- 

 less circling about their suns, and the many un lighted orbs in 

 their midst, probably thousands of millions, is only one of 

 thousands of such star clusters that are within the range of 



*A lecture written In 1884, and delivered before the Rochester Academy of Sciences and 

 on A'arious other occasions. 



