Lightning 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 ; thus determining for 
itself a passage between the points of action through such line or lines 
a3 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, however, 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 a 
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 which is but too frequently verified in the damage so con- 
Stantly 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 
“Wappen ae Na . 
* Case (7), .p. 851. A minute account will be found in the Liverpool Commercial 
Chronicle, in May, 1827. The conducting chain, at the time of the first explosion, 
Ms ed away in its box below, although set up in time to prevent the effects of 
the Second explosion. 
Vor. XXI—No. 2. 45—2 
