532 The Sniithsonian Institittiofi 



in the Smithsonian Report for 1857 an invaluable contribution 

 to its history will be found. It includes his deposition taken 

 in Boston in 1849, as it appears in the record of the Su- 

 preme Court of the United States, which is itself a concise 

 history of the invention. In consequence of its appearance, 

 Professor Morse was induced to publish certain statements 

 reflecting upon the integrity and scientific repute of Henry, 

 and this led to an investigation of the whole subject, at 

 Henry's request, by the Board of Regents, resulting in the 

 unanimous adoption of resolutions exonerating him from any 

 charge made by Morse. 



Henry's continued interest in meteorology led him to pay 

 much attention to thunder-storms, the effects of lightning, the 

 aurora, studies of atmospheric electricity, earth-currents, etc., 

 all of which found recognition in the earlier publications of the 

 Institution. Among others were papers on "Atmospheric 

 Electricity," by Duprez; on "Earth Currents," by Matteucci ; 

 on "The Aurora," by Loomis ; and many reports upon the effect 

 of lightning. Henry himself prepared a very valuable circular 

 on " Lightning Rods," giving rules for their erection and 

 proper care. Mention should also be made of another paper 

 of great interest to students of electricity a generation and 

 more ago, on " The Use of the Galvanometer as a Measuring 

 Instrument," by J. C. Poggendorff. One of the earliest 

 methods of " calibrating " a galvanometer is here explained 

 and much information is given relating to what was then in 

 large measure an unexplored field. 



Two of the most important papers relating to electricity 

 which the Institution has published are those of Helmholtz 

 and Maxwell in the Smithsonian Report for 1873, presenting 

 the (at that time) latest notions regarding its nature, and 

 Tunzelmann's account of Hertz's researches, which will be 

 found in the Report for 1889. In reprinting monographs 



