and on the Defence of Shipping from Lightning. 1 77 



" examination." The next eight pages consist of notices of 

 the damage done to the Rodney, copied from the news|)apers 

 of the day, of a few extracts from the statements made by 

 naval officers who had witnessed the protecting effects of my 

 conductors, and of a few desultory remarks on those state- 

 ments; here then are thirteen pages to begin with, containing 

 no kind of scientific research whatever. The next three pages 

 and a half contain a few ill-contrived repetitions of Priestley 

 and Cavallo's experiments, made above fifty years since, on 

 the residual electricity of a Leyden jar, and which Mr. Stur- 

 geon, by a most unhappy blunder, has taken as a lateral dis- 

 charge produced at the instant of the primary discharge *. 

 " This residual electricity (observes Cavallo) should be care- 

 fully considered in performing delicate experiments f ". 



The remaining 15 pages contain merely ill-digested remarks, 

 resting on the above fallacy; designing appeals to the fears of the 

 iminformed; an account of a few common-place and inevitable 

 results of ordinary electrical action on a kite ; and a proposal 

 to place copper rods in various ways about the rigging of a 

 ship as a defence against lightning, in open defiance of his own 

 previous admissions; with a few considerations of the expense 

 attendant on it. 



How such a paper as this can fairly come under the deno- 

 mination of " Theoretical and Experimental Researches in 

 Electricity," when not above two out of thirty-two pages, or 

 about one sixteenth of the whole, contain any experiment at 

 all, — the experiments not original, and the reasoning upon 

 them a fallacy, — I am really at a loss to determine. 



In my former communications, which appeared in this 

 Journal in December, 1839, and February and May, 1840, 

 I have given a complete exposition of these and other points 

 contained in this memoir; so that but little more remains to 

 notice than the deceptive colouring in which Mr. Sturgeon 

 has thought fit to disguise my experiments, and his illiberal 

 dealing with every one holding opinions adverse to him- 

 self. 



The simplicity and convenience of my fixed conductors 

 having, as I have already stated, been in the year 1820 fully 

 admitted, the Navy Board at that time thought proper to 

 call upon me to illustrate and investigate experimentally, so 

 far as possible, their probable operation through the ship. 



* Lond. and Editib. Pliil. Mag. for December, 183i). 



t Mr. Sturgeon appears to be well aware of the great mistake he has 

 made on this point. In no place, so far as 1 know, has he attempted to 

 defend it. 



Fhil. Ma<r. S. 3. Vol. 18. No. 116. March 184.1. N 



