LigJitning Conductors in Ships. 353 



In this case considered to happen, not where the best conductors are, 

 but where they are not; so that the mariner has to contend with a 

 constantly" exploding principle, which continues its devastations in all 

 those points where it ceases to be transmitted 5 thus determining for 

 itself a passage between the points of action through such line or lines 

 as may, upon the whole, oppose to it the least resistance. 



11. Such effects being constantly observed, not only on ship-board, 

 but on shore, it became a grand question of scientific consideration, 

 how far it would be prudent to provide for the electric matter an effi- 

 cient conducting line, between the highest points of a ship and the 

 sea, so as to offer the least resistance to the progress of such a pow- 

 erful agency, and transmit it in a state of low tension between the 

 points of action ; on the same principle that persons, dreading an in- 

 undation, would provide a channel to carry off the water as easily as 

 possible ; an idea, as is well known, first suggested by the celebrated 

 Dr. Franklin, and since carried into practice with considerable suc- 

 cess ;. the conducting line having the name of Lightning-Conductor 

 or Lightning-Rod. 



12. Although the application of lightning-conductors to buildings on 

 shore is always judicious, and their advantages are very apparent, yet 

 on ship-board, where the effects of lightning are most to be dreaded, 

 the introduction of this means of defence has been slow and imper- 

 fect. The conductor hitherto employed at sea consists of long flexi- 

 ble chains or links of metal, about the size of a goose-quill, sometimes 

 of iron : those employed in H. M. Navy, how^ever, are of copper ; 

 they are usually packed in a box, and are intended to be set up from 

 the mast-head to the sea when occasions require, so that, as observed 

 by Mr. Singer, in his excellent work on electricity, partly from inat- 

 tention, and partly from prejudice, they frequently remain in the ship's 

 hold during long and hazardous voyages quite unemployed ; a remark, 

 the truth of w^hich is but too frequently verified in the damage so con- 

 stantl}'' happening at sea during lightning-storms.* 



13. The necessity of providing the best possible security against 

 the effects of lightning on ship-board has been long admitted ; but 

 continuous and fixed metallic rods have been deemed inapplicable to 



* Case (/.), p. 351. A minute account will be found in the Liverpool Commercial 

 Chronicle, in May, 1827. The conducting chain, at the time of the first explosion, 

 was stowed away in its box below, although set up iu time to prevent the effects of 

 the second explosion. 



Vol. XXL— No. 2. 45—2 



