Historical and Personal 5 



An attendant*, "Richard," appears occasionally, to help in turning 

 the electrical machine, or in pulling the strings which made or broke the 

 electrical connexions; and sometimes he is even asked his opinion as to 

 the comparative strength of two electric shocks f. But there is no record 

 of any other person having been admitted into the laboratory during the 

 series of experiments to which we now refer. 



The authority of Cavendish in electrical science was of course estab- 

 lished by his paper of 1771, and accordingly we find him nominated by 

 the Royal Society as one of a committee appointed in 1772 "to consider 

 of a method for securing the powder magazine at Purfleet J." 



A powder mill at Brescia having blown up in consequence of being 

 struck by lightning, the Board of Ordnance applied to Mr Benjamin Wilson, 

 F.R.S., who held the contract for the house-painting under the Board, 

 and who had some reputation as an electrician, for a method to prevent 

 a like accident to their magazines at Purfleet. Mr Wilson having advised 

 a blunt conductor, and it being understood that Dr Franklin's opinion, 

 formed upon the spot, was for a pointed one, the matter was referred, in 

 1772, to the Royal Society, and by them as usual to a committee, who 

 after consultation presented a method conformable to Dr Franklin's 

 theory || . 



The Committee consisted of Cavendish, Dr, afterwards Sir William 

 Watson, Dr Franklin, Mr J. Robertson (Clerk and Librarian to the Royal 

 Society), Mr Wilson and Mr Delaval. 



Dr Franklin read to the Committee a paper which is printed in his 

 works, vol. v. p. 435, but is not referred to in the report of the Committee, 

 though the report is entirely in conformity with it ^j. 



The Committee went down to Purfleet and examined all the buildings 

 together, but I cannot trace any evidence that Cavendish did anything 

 to modify the report, and Franklin does not mention him in any part of 

 his writings, as one of the remarkable men with whom he was brought in 

 contact. 



The most noteworthy incident of the Committee was the dissent** of 

 Mr Wilson, to which Mr Delaval adhered as regards that part of the report 

 which recommended the conductors to be pointed. Mr Wilson followed 

 up his dissent by a paper ff , in which he gave his reasons for preferring 



* Arts. 242, 560, 565. f Art. 511. 



J See Franklin's Works, vol. v. p. 430, note. 



He also painted portraits of Franklin and of Gowin Knight, as well as of 

 Garrick in various characters. 



|| Phil. Trans. 1772, p. 42. 



f The report is printed in Franklin's Works, vol. v. p. 430, and is there stated to 

 be "Drawn up by Benjamin Franklin, August 21, 1772." The paper on the utility 

 of long, pointed rods is stated to have been read on August 27th, 1772. [On the 

 general subjectof atmospheric electric discharges seeC.T. R. Wilson, Phil. Trans. 1920.] 



** 1-hil. Trans. 1772, p. 48. tt Ib. p. 49. 





