868 Mr Scoresby ow the Effects of the Sea at great depths^ 
Froln this table we may observe, that the greatest increase of 
specific gravity, by pressure, in the specimens of the different kinds 
of wood submitted to experiment, was obtained by the fir; the next 
greatest by the ash ; the next by the elm ; the next by the oak ; 
the next by the teak ; the next by the hickery ; and the least by 
the mahogany. The cork gained still less than any of the 
pieces of wood. The proportion of impregnation of the same 
kind of wood, in specimens of different sizes and shapes, is de- 
rived from the experiment’s made on the ash ; and it is curious 
to observe, that the largest cube of ash. No. 14, and the paraf- 
lelopipedon of the same. No. lOj received the greatest propor- 
tional increase of weight ; while the smaller pieces received less 
and less additional weight, per cubic inch, as they decreased in 
size. Thus, No. 14, containing about 4 solid inches of wood^ 
gained 145 grains per cubic inch ; No. 13. of about 3 solid 
inches, gained 143 grains per cubic inch; No. 11. of 2 solid 
inches, gained 137 grains per inch; and the specimens of 1 
inch, solid contents, gained from 127 to 135 grains. It is also 
a little curious, that the specimens sent to the depth of 2058 
feet, were as much impregnated as those sent down above 6000 
feet. The cube of ash. No. 11. consisting of 2 solid inches of 
wood, gained 137 grains per inch, at the depth of 6348 feet, 
while a similar specimen gained 138 grains, at the inferior depth 
of 3708 feet. In the same way, a cube of 4 solid inches gained 
145 grains per inch, at the extreme depth; and 144 grains per 
inch, at the depth of 4836 feet. The degree of impregnation 
of the one-inch cubes of ash, produced by immersion to the 
depth of 2058 feet to 6348 feet, varies irregularly, but is evi- 
dently as great at the depth of 2058 feet, as under any superior 
pressure ; so that it is probable that the greatest permanent im- 
pregnation by pressure, of such open-grained woods as ash, elm, 
fir, &c. is produced at the depth of 300 or 400 fathoms. 
Hence, it is clear that no use can be made of this effect of pres- 
sure, for determining the depth, unless it be within 2000 feet of 
the surface ; and even in this limit, the results may be unceiv 
tain. 
From a comparison of column vii. with xiii., and column iv. 
with XV., it appears, that an effect of the impregnation of the 
wood with sea-water, was to increase its dimensions, as well as 
