TAEMEKS' INSTITUTES. 247 



tlie same law ^voukl bold in the case of electrical conduction, but this is not the 

 view lield by the masters in this ecience. If the copyists and mere book-makers 

 have handed down this erroneous view, that is their mistake and our misfortune ; 

 but erroneous views and false theories do not alter nature's laAvs, 



I will now quote a few authorities, — not the compilers of text-books foi' dis- 

 trict schools or those employed to write up some subject for a cyclopaedia, but 

 men who are everywhere regarded as masters in this branch of science, quoting 

 from the highest authorities in England, France, Switzerland, and the United 

 States. 



In the British association in 1854, Faraday was requested to give liis opinions 

 in regard to lightning conductors. "On being asked whether a flat strip of 

 coj)2)er was not better than a copper rod. Prof. Faraday said the siuipe of the 

 conductor is immaterial, provided the substance and quality of the metal are the 

 same." — [American Journal of Science for 1855, p. 140. 



Prof. Miller of King's college, London, in his Chemical Physics, fays: '^'It 

 must be observed that in all cases of conduction the charge passes through the 

 whole thickness of the rod or wire, and is not confined to its surface ; it there- 

 fore makes no difference whether tlic metal is in the form of a wire, or is 

 extended over a large surface m leaf." — [Chemical Physics, page 350. 



Desclianel of France says : "There are two exceptions to the rule that elec- 

 tricity is confined to the external surf ace of a conductor: 1. It does not hold 

 for electric currents. We shall see hereafter, in connection with galvanic elec- 

 tricity that the resistance which a Avire of given lengtli opposes to tiie passage of 

 electricity through it depends not upon its circumference, but upon its sectional 

 area. A hollow Avire Avill not conduct electricity so Avell as a solid Avire of the 

 same external diameter." — [Natural Philosophy, p. 525. 



De la Rive of SAvitzerland, in his Avork on electricity, which is everyATherc 

 ranked as the higliest authority, says: " DaA'y, Becquerel, Harris, Cumming, 

 and generally all philosophers who luiA'e directed their attention to the conduct- 

 ibility of bodies for electricity, haA'e commenced by proving that the conduct- 

 ing poAver of a Avire is in iuA'crse ratio of tlie length, and in direct ratio of tlie 

 section of tlie Avire." — [Treatise on Electricity, vol. ii, p. 82. 



Prof. Joseph Henry, secretary and director of the Smithsonian institution in 

 Washington, the highest authority on electricity in this country, in his directions 

 for the construction and erection of lightning-rods, says: "The rod should 

 consist of round iron, of not less than three-fourths of an inch in diameter. 

 * * * Other forms of rod, such as flat or tAvisted, AA'ill conduct 

 the lightning, and in most cases ansAver sufficiently Avell. They tend, hoAVCA'cr, 

 to give off lateral sparks from the sharp edges at the moment of the passage of 

 the electricity through them, AA'hicli might in some cases set fire to A'ery com- 

 bustible material." — [American Journal of Science for 1871, p. 344. 



AVith such witnesses as Faraday, Miller, Deschanel, De la Kive, and Henry, 

 bearing such decisiA'e and indisputable testimony, I clieerfully submit my case. 



Mr. Lanphere also complains that I left many of my hearers in doubt 

 regarding my belief in the efficiency of lightning-rods. 



I distinctly said in tlie beginning that I did not propose to give farmers any 

 advice as to AA'hetlier they should or should not attach lightning-rods to their 

 buildings. A speaker should have the right to limit the field of his remarks. 

 But since complaint is made that I did thus limit my subject, I will endeavor 

 to answer all objection on this p)oint, and tell Avhat my belief is. 



I belicA'e that such a rod as I recommended at ColdAvater and put up in the 



