SEA 
covers, that people may not fall down 
through them in the night. Scuttle is also 
h name given to those little win'dows and 
long holes which are cut out in cabins, to 
let in light., 
SCYLLiEA, in natural history, a genus 
of the Vermes Mollusca class and order. 
Body compressed, and grooved along the 
back ; mouth consists of a terminal tooth- 
less aperture ; tentacula, or arms, three oh 
each side, and placed beneath. Two spe- 
cies are noticed, tiz. the Pelagica and Gom- 
pbodensis. 
SCYTHROPS, the Channel-Ull^m natural 
history ; a genus of birds of the order Picae. 
Generic character : the bill large, convex, 
cultratcd, furrowed at the sides, hooked at 
the tip ; nostrils round, naked at the base 
of the bill ; tongue cartilaginous, split at 
the point ; toes two before, and two be- 
hind ; tail of ten feathers. Of this genus 
only one species is known. This is an in- 
habitant of New South Wales, and is gene- 
rally designated as the New South Wales 
Channel-bird. Its size is that of a crow; 
but its length is considerably greater, mea- 
suring two feet seven inches. It is seldom 
seen, excepting in the morning and even- 
ing, generally in pairs, sometimes in very 
small docks; its noise resembles the scream- 
ing sound of alarm uttered by poultry in 
danger. It is migratory, and supposed to 
feed on the seeds of trees, on fruits, and the 
exuviae of beetles. The tail is sometimes 
Unfolded like a fan, both during the flight 
and sitting of the bird, and gives it an in- 
teresting and dignified appearance. It ap- 
pears not to be easily tameable ; but of the 
nature, manners, and habits of this bird, 
little is at present ascertained. 
SE.4, is frequently used for that vast 
tract of water encompassing the whole 
earth ; but is more properly a part or divi- 
sion of these waters, and is better defined a 
lesser assemblage of water, which lies before, 
and washeth the coasts of, some particular 
countries, from whence it is generally de- 
nominated, as the Irish Sea, the Mediter- 
ranean Sea, the Arabian Sea, &c. 
What proportion the superficies of the 
sea bears to that of the land, is not pre- 
cisely knowh, though it is said to be some- 
what more than tv^b-thirds. As the waters 
Of the earth must necessarily rise to the 
surface thereof, as being specifically lighter 
than the earth, it was necessary there 
should be large cavities therein, for recep- 
tacles to contain them, otherwise they 
would have overspread all the superficies 
VOL. VI. 
SEA 
of the earth, and so have rendered it utterly 
uninhabitable for terrestrial animals; for 
^the centre of the earth being the common 
centre of gravity, and the nature of fluids 
being such, that they equally yield to equal 
powers ; and the power of attraction being 
every where equal at equal distances froni 
the centre, it follows, that the superficial 
parts of the water will every where con- 
form themselves to an equidistant situation 
from the centre, and, consequently, will 
form the siirface of a sphere, so far as they 
extend. Hence, that the sea seems higher 
than the earth or land, results from the fal- 
lacy of vision, whereby all Objects, and the 
parts of land as well as sea, the further 
they are off from us, the higher they ap- 
pear ; the reason of all which is plain from 
optics ; for it is well known, that the denser 
any medium is, through \vhich vfe behold 
objects, the greater is the refraction ; or the 
more their images appear above the hori- 
zontal level ; also the greater quantity of 
the medium the rays pass through, the more 
will they bC bent from their first direction ; 
on both these accounts, the appearances of 
things remote, and on the sea, will be some- 
what above the horizon, and the more so' 
as they are the more remote. 
With regard to the depth of profundity 
of the sea, Varenius affirms, that it is iri 
some places unfathomable, and in other 
places very various, being in certain places 
joj h im> lio) 2,%, 4i English miles, in other 
places deeper, and much less in bays than 
in oceans. In general, the depths of the 
sea bear a great analogy to the height of 
mountains on the land, so' far as is hitheftb 
discovered : and it is a general rule among 
sailors, and is found to hold true in inany 
instances, that the more the shores of any 
place dre steep and high, forming perpendi- 
cular cliffs, the deeper the sea is below, 
and that, bn the contrary, level shores de- 
note shallow seas. Thus the deepest part 
of the Mediterranean is generally allowed 
to be under the height of Malta. And the 
observation of the strata of earth and other 
fossils, on and near the shores, may serve tb 
form a good judgment as to the materials 
to be found in its bottom. For the Veins of 
salt and of bitumen doubtless run on the 
same, and in the same order, as we see 
them at land ; and the strata of rocks that 
serve to support the earth of hills and ele- 
vated places on Shore, serve also, in the same 
continued chain, to support the immense 
quantity of water in the bason of the sea. 
The coral fisheries have given bccasibn 
E 
