PREFACE. 



about the same period. I now prepared to commence what 

 might properly be called the grand tour of the states ; and be- 

 ing accompanied by my family, the consequent expenses of 

 travelling for so long a time, and through such distant coun- 

 tries, became a subject of consideration. Besides this view 

 of my projected tour, another presented itself. Might I not 

 render myself useful to the public, while gleaning information 

 from them ? and in the act of being useful to them, might I 



O ' O 



not multiply and enlarge the means of obtaining the informa- 

 tion of which I was in quest ? Since my arrival, I had often 

 been solicited to deliver in one or other of the chief cities pop- 

 ular lectures on scientific subjects, such as I had occasionally 

 given in England. I had already observed that the American 

 public in New York and Philadelphia manifested more than 

 ordinary taste for that species of oral instruction. Societies 

 under various denominations existed in these cities and else- 

 where, whose chief object was to get up weekly lectures on 

 miscellaneous and unconnected subjects, delivered by various 

 individuals invited for the purpose by the directors of such 

 societies. These lectures, although for the most part since 

 discontinued, were at that time popular and numerously at- 

 tended. The success of these projects was the more encour- 

 aging when the quality of the article so greedily enjoyed by 

 the public was considered. It is true, that among the numer- 

 ous discourses thus brought together from all parts of the 

 Union, some were found eminently possessing the qualities 

 which such discourses ought to have, and which were well 

 deserving of success. But these were like angels' visits, few 

 and far between 



Apparent rari nantes in gurgite vasto. 



In general, the history of such productions might be thus 



