S06 Mr Scoresby on the Effects of the Sea at great depths, 
case, it would serve a very valuable purpose, since all the plans 
hitherto contrived for measuring depths from a vessel, when 
^ sailing slowly, or drifting through the water, cease to be useful 
beyond SOO or 300 fathoms. With this view, I not only at- 
tached pieces of wood of different kinds, to the lead, and pro- 
vided counterparts for immersion in a bucket of water ; but I 
also fastened cubes of ash, from the same piece of timber, of 
about one inch solid contents, and of exactly the same weight, to 
thc: line, at intervals of about 500 feet ; by the weight of which, 
when taken up, I could ascertain whether the increase of speci- 
fic gravity was in any w'ay proportionate to the depth. When 
the specimens of wood for this experiment were procured, a 
clear grained piece, of double the size wanted for sending under 
water, was prepared, and then cut in two, and the two parts 
dressed to the same shape, and to within a quarter of a grain 
of the same weight : one of these was then adopted as a prin- 
cipal, and fixed to the lead or line ; and the other as a counter- 
part, and put into a bucket of water. The specimens affixod to 
the lead were eleven in number, and consisted of Avood of dif- 
ferent kinds, shapes, and dimensions : they were sunk to the 
depth of 6348 feet, and the line was almost perpendicular for 
nearly an hour. 
Each piece of. wood attached to the line, was taken off as 
hauled in, plunged in a basin of water, and conveyed into the 
cabin, where its weight in air and in fresh water v/as immediate- 
ly taken. The interval between any two pieces was such, that 
I had just time to determine the specific gravity of one, before 
the next came up. On the arrival of the lead, the attached 
specimens were immediately immersed in water, and weighed as 
quickly as possible, together with their counterparts, which had 
been secured at the bottom of a bucket of sea-water, during 
the time the experiment was in progress. 
The following Table exhibits the results of this experiment. 
