804 THE POPULAR SCIENCE MONTHLY. 



all important points on the way. Instruction by lectures and exami- 

 nations was given in mineralogy, geology, botany, zoology, chemistry, 

 experimental philosophy, and practical mathematics, particularly land- 

 surveying, harbor-surveying, and engineering. One of the largest 

 boats in the flotilla was fitted up as a laboratory, with cabinets in 

 mineralogy and geology, and also scientific books for reference. Stu- 

 dents were taught the method of procuring specimens, and were re- 

 quired to make collections of whatever was interesting on the route. 



The public mind was finally awakened to the importance of the 

 work which these explorers and investigators had carried on single- 

 handed. Government now came to the aid of science. In 1824 one 

 State Legislature, that of North Carolina, authorized a geological sur- 

 vey to be made. This example was followed in 1830 by Massachusetts, 

 and soon after by New York, Pennsylvania, Virginia, and other States, 

 and also by the national Government, until, as is now well known, the 

 whole territory of the United States and Canada either has been or is 

 in the process of being surveyed. Several of the State surveys pub- 

 lished independent volumes on the mineralogy of their respective 

 States, and these surveys have been a powerful auxiliary in extending 

 our knowledge of the occurrence of minerals on this continent. The 

 opening of mines and quarries throughout the country has also fur- 

 nished abundant material for study. The large number of original 

 contributions which have been published in the volumes of State sur- 

 veys, the treatises by American authors, and the still larger number of 

 memoirs and papers communicated to our academies of science and 

 scientific journals, can not be even enumerated in this place ; neither is 

 it my purpose to attempt to give here a list of the names of those who 

 have been actively engaged in making researches on American min- 

 erals. Still less can I attempt to give an account of the work that has 

 been and is being done by living mineralogists. The sketch which I 

 have presented of the four typical workers has in a measure shown the 

 character of our early mineralogists, the earnest spirit in which they 

 labored, and what they accomplished in the first quarter of the cen- 

 tury. The point to which the science has reached in the last quarter 

 of the century can not be unfamiliar to you all. 



In the time that remains I desire to call your attention to some of 

 the developments made in the field in which our mineralogists have 

 worked. It was thought by many scientists in the first half of this 

 century that our rocks seemed likely to afford less variety of mineral 

 contents than the rocks of Europe. Further study, however, and more 

 careful and extended observations, encourage us to believe that our 

 mineral riches, even in variety of species, will compare favorably with 

 those of other continents. Already fully one half of the known min- 

 eral species have been found here. The present number of known 

 minerals is variously estimated to be from seven hundred to one thou- 

 sand. There have been described, as occurring here, nearly three hun- 



