174- Mr. Snow Harris o;j Lighhmig Conductors^ 



of conductor ever generally used by the English, consists of 

 links of small copper rods under the form of a flexible chain 

 triced up, as occasion required, to the mast-head and al- 

 lowed to touch the sea, a contrivance recommended by the 

 learned Dr. Watson in the year 1762, in a letter to Lord 

 Anson, then First Lord of the Admiralty. 



The damage, however, which, notwithstanding every sug- 

 gestion of the kind, continued to occur to shipping from at- 

 mospheric electricity, and especially to our navy, showed that 

 such methods had not fully met all the circumstances of the 

 case ; hence the necessity of resorting to some system of de- 

 fence, difi^ering essentially from those hitherto tried. Now 

 that system which experience indicated evidently embraced 

 the following principles. 



1. The conductor should be permanently fixed, so as to be 

 always in place, and at all times ready to meet the most un- 

 expected clanger, 



2. It should be continuous and of considerable electrical 

 capacity, so as to admit of a rapid equalization of the electrical 

 action. 



3. It should in no way interfere with the standing or run- 

 ning rigging; should admit of the motion of the sliding masts 

 without deranging its existing state; and in case of either be- 

 ing removed by accident or design, the remaining portion of 

 the conductor should be still as efficient as before. 



4. It should be independent of the crew of the ship, and 

 not be left to them to put in place or not, as may be deemed 

 requisite ; or require any handling, to their great annoyance, 

 — under many circumstances to their imminent peril. 



5. It should be so applied that a discharge of lightning 

 falling on the vessel, could not enter into any circuit of which 

 it did not form a part. 



The desirableness of such a plan as that which in the year 

 1820 I proposed to the Admiralty, embracing, as it did, every 

 required condition, was admitted. The doubts, however, ex- 

 isting at the time were, whether it was fully borne out in all 

 its details by a sufficient number of facts in science; and 

 whether it could be carried out so perfectly as to meet the 

 many variable circumstances in which the general fabric in all 

 its casualties might become placed ; but no doubt existed of 

 the propriety of adopting such a form of conductor, were 

 these questions satisfactorily disposed of. 



Your readers are no doubt aware, that the method I pro- 

 posed, was to make the masts themselves perfect conductors 

 of electricity, by incorpoiating with them in a peculiar way 



