332 
Dr Traill on the Copper-Sheathing of Ships. 
place, as soon as the water had left her. The copper appeared 
no more reduced than at the termination of the first voyage. 
The iron was diminished generally about § inch in breadth, and 
from J to J inch in thickness, at the ends of the vessel, for about 
2 or 3 feet. The iron was much more reduced there than at 
any other part. It was covered with the usual rust, not at all 
resembling cast-iron under similar circumstances. The fiat of 
the ship^s bottom, from end to end, and from 6 to 8 feet in 
breadth, was full of fleshy barnacles * of uncommon length, and 
a few of the hard-shelled species -f. What remained of the iron 
is still considered a sufficient protection for a third voyage to 
India ; and it appears only to be necessary to drive the large 
copper nails up a little, to secure the iron bars for the next 
voyage.” 
I may add, that all the balani died and corrupted before the 
ship came into the graving-dock ; but many of the lepades were 
alive when I examined the bottom. / 
The alleged over-defence of this vessel cannot be inferred 
from the accumulation of shell-fish. If the negative electricity 
was the cause of the deposition of calcareous matter , it ought to 
have been deposited indiscriminately on any part of the copper ; 
but it was not deposited, except in the perfectly organized shells ; 
and not a speck of calcareous deposit was on any part of the 
copper, except under the animals. To consider a beautifully 
organized body, as the shell of the balanus is known to every 
naturalist to be, as a mere electro-chemical deposition, is not 
much less fanciful than to regard the other functions of the ani- 
mal in that light J. 
* Lepas anatifera. + Balanus Tintinnabulum. 
$ The application of copper to ships’ bottoms, was originally intended to guard 
the lower timbers from the weeds and worms which continually imbedded them- 
selves in long voyages, occasioning great impediments to sailing, and even en- 
dangering the lives of the seamen. In the action of Sir Edward Hughes with the 
French fleet under Suffrein, in the East Indies, in the year 1782, the latter ob- 
tained advantages over the British, having arrived from Europe with copper-bot- 
tomed ships, which enabled them to keep the weather-gauge of Admiral Hughes, 
whose fleet was composed of wood-sheathed bottoms, overgrown with weeds and 
barnacles. In fact, the value of clean-bottorped ships, enabled the French to force 
the fleet of this country into five general actions, and to gain many signal advan- 
tages. 
The first vessel known to have been coppered in England, was the Alarm fri- 
