200 IIISTOEY OF ELECTEICITY. 



by incorporating with them, in a peculiar way, two laminpe of sheet- 

 copper, uniting these with the metallic masses :ui the hull bv other 

 laminre, and giving the whole a free communication with the sea. 

 This method was tried experimentally, both on models and to a lar^r 

 extent in the navy itself; and a Commission appointed to examine the 

 result reported themselves highly satisfied with Mr. Harris's plan, and 

 strongly recommended that it should be fully carried out in the Navy. 10 ] 



It is not here necessary to trace the study of atmospheric electricity 

 any further : and we must now endeavor to see how these phenomena 

 and laws of phenomena which we have related, were worked up into 

 consistent theories ; for though many experimental observations and 

 measures were made after this time, they were guided by the theory, 

 and may be considered as having rather discharged the office of con- 

 firming than of suggesting it. 



We may observe also that we have now described the period of 

 most extensive activity and interest in electrical researches. These 

 naturally occurred Avhile the general notions and laws of the pheno- 

 mena were becoming, and were not yet become, fixed and clear. At 

 such a period, a large and popular circle of spectators and amateurs 

 feel themselves nearly upon a level, in the value of their trials and 

 speculations, with more profound thinkers : at a later period, when the 

 subject is become a science, that is, a study in which all must be left 

 far behind who do not come to it with disciplined, informed, and logi- 

 cal minds, the cultivators are far more few, and the shout of applause 

 less tumultuous and less loud. We may add, too, that the experiments, 

 which are the most striking to the senses, lose much of their impres- 

 siveness with their novelty. Electricity, to be now studied rightly, 

 must be reasoned upon mathematically ; how slowly such a mode of 

 study makes its way, we shall see in the progress of the theory, which 

 we must now proceed to narrate. 



[2nd Ed.] [A new mode of producing electricity has excited much 

 notice lately. In October, 1840, one of the workmen in attendance 

 upon a boiler belonging to the Newcastle and Durham Railway 

 reported that the boiler was full of fire ; the fact being, that when he 

 placed his hand near it an electrical spark was given out. This drew 

 the attention of Mr. Armstrong and Mr. Pattinson, who made the cir- 

 cumstance publicly known. 17 Mr. Armstrong pursued the investigation 



w See Mr. Snow Harris's pancr in Phil. Jfag. M:\rch, 1841. 

 ' 7 Phil. Maa. Oct. 1840. 



