IV PREFACE. 



cuse, " non mea culpa sed tempoms" The topics, however, of this 

 nature often contain valuable suggestions and germs of truth, and, 

 even when their falsity is unquestioned, display an amount of 

 ingenuity not always found in real and true inventions. Such mat- 

 ters belong, of right, to the scientific history of the times, and on 

 no account ought to be omitted. 



The Editor would take this opportunity to say, that he does not 

 endorse, or consider himself responsible for, any opinions advanced in 

 the body of the work, unless over his own signature. The selec- 

 tions have generally been made upon good authority, which, in most 

 cases, is given in connection with each article. In the volume for 

 1851, a series of Editorial Notes, on the general progress of science 

 during the preceding year, was given. The favor with which these 

 have been received, leads to their continuance. As some objection 

 has been made to certain remarks by the Editor, included in the 

 notes for 1851, we would here say, that they are to be considered as 

 an editorial table, in which the Editor will exercise the right of 

 freely expressing such sentiments and opinions, relative to scientific 

 matters, as to him shall seem proper. 



Heretofore the Annual of Scientific Discovery has appeared under 

 the editorial charge of David A. Wells and George Bliss, Jr. 

 Mr. Bliss having left the country for a temporary residence in 

 Europe, the work has passed entirely under the charge of the first- 

 named Editor. While we regret the withdrawal of Mr. Bliss, whose 

 many and varied attainments have contributed to the success of the 

 Annual, it will be the aim of the present Editor to sustain and im- 

 prove, in all respects, the character of the work. 



To the friends, not only in this country, but in Europe, China, 

 and California, who have kindly furnished scientific information, we 

 return our most sincere thanks. 



We present to our readers, in the Annual of Scientific Discovery 

 for 1852, a portrait of Professor Joseph Henry, President of the 

 American Association for the Advancement of Science, 1849-50, 

 and the present Secretary of the Smithsonian Institution, at Wash- 

 ington. 



CAMBRIDGE, February, 1852. 



