r 



i q PREFACE. 



J such a project may seem to have been, it was nevertheless j 

 j perfectly successful, not in one, or in two, or in three cities, 

 \ but in every part of the Union. This will explain much 

 that might otherwise appear strange in the subject and con- 

 tents of these volumes. The miscellaneous character of the 

 subjects discussed the rejection of all attempt at system- 

 atic arrangement and the varying length of the articles - 

 all correspond with the lectures as they were delivered to the 



public. 



It is scarcely necessary to observe that the same series of 

 discourses was not given in all places which I visited, nor 

 was the entire collection contained in the present volumes 

 given in any one place. Most of these essays were, however, 

 on some one or other of my visits to New York, Philadelphia, 

 and Boston, given in those cities. 



A considerable number of these essays were prepared ex- 

 pressly for my lectures, among which may be mentioned all 

 those on astronomical subjects, with one or two trifling excep- 

 tions, and several of those on steam. The substance of some 

 have been incorporated in one or other of my former works, 

 but in every case they have been more or less modified and 

 adapted to their present purpose. 



The object of this miscellany is not to enlighten those who 

 devote themselves to the regularly-disciplined study of those 

 sciences and arts which are here so slightly and popularly 

 iched. My purpose has been to instruct and inform, and 

 at the same time rationally to amuse, those who have neither 

 time, inclination, nor opportunity, to cultivate mathematics, bj 

 ( which alone a strict professional knowledge of astronomy, 

 ( mechanics, and physics, can be acquired. To have attempted 

 to adapt the work to both classes to those who merely seek 

 lor general information on these subjects, without pursuing 



