OF ARTS AND SCIENCES. 329 



of me'i of the highest order. The observational powers of science have 

 beeu greatly extended through tlie consequent invention of those grand 

 instruments, the telescope, the microscope, the spectrometer. Through 

 these we have obtained more majestic views of the nature of the uni- 

 verse. Through tliese we are able to contemplate the structure and 

 genesis of other systems of worlds, and are gathering information as 

 to the chemical coustitution and liistory of the stars. 



In this noble advancement of science you, through some of your 

 members, have taken no inconspicuous part. It adds impressively to 

 the honor you have this day conferred on me, that your action is the 

 deliberate determination of competent, severe, impartial judges. I 

 cannot adequately express my feelings of gratitude in such a presence, 

 publicly pronouncing its approval on what I have done. 



I am, gentlemen, very truly yours, 



John W. Draper. 



Professor Watson gave an account of an excursion upon 

 the Marne, with a description of the drum-weirs and river- 

 gates for inland navigation. 



Professor Cooke exhibited the radiometer of Professor 

 Crookes, and gave tlie results of some ex]3eriments he had 

 made with it. 



Professor William Everett presented a communication on 

 the sources of the Nile. He first called attention to the fact 

 that the wonderful extension of our knowledge in the last 

 few years on this subject had come from explorations directed 

 from the south, rather than from the direction of Egypt. 

 In connection with these expeditions, attention had again 

 been directed to earlier discoveries. The veracity of the 

 Portuguese explorers had been attested, and the value of 

 some of the very earliest accounts reasserted. Dr. Living- 

 stone especially had dwelt with great confidence — probably 

 too great — on Herodotus's view of the Nile sources. But a 

 still earlier writer than Herodotus had not received due 

 attention. In the Prometheus of ^schylus, lines 800-815, 

 the wanderings of lo are described with some vagueness, it 

 is true, but in terms which appeared to Professor Everett to 

 indicate a journey to the extreme east, afterwards tending 



