1810.] 
to be applicable to the treatment of impedi- 
ments. Inthe mean time, 1 am yet free to 
aeknowledge, that, on the subject of what 
the compiler has called the ¢¢ orthoepical 
junction of words,” the Grammar of Eng- 
lish Pronunciation, (though not free from 
mistakes and fallacies) may be consulted with 
some advantage. If the last chapter had 
been done as well, I might have passed over 
the plagiary in silencet for the interests of 
Science would not then have been essentially 
injured ; and me, most assuredly, it is not 
in the power of Mr. S. to injure. 
Ositcher 22, 1810. J. THEerwacr. 
ECE 
Yo the Editor of the Monthly Magazine. 
SIR, 
] OFTEN puzzle persons, who in ge- 
neral reason closely, by asking them, 
Why « boat sinks when a hole is made in 
the bottom ? 
Many of your readers, from habitually 
sonsidering this cause and effect as inse- 
parable, will be disposed to smile at the 
question, I will, however, prove its claim 
to consideration, by reminding them, that 
the boat, which sinks when there is a 
hole in the bottom, is specifically lighter 
than water: that is, we have in this fact, 
the philosophical paradox of a body sink- 
ing in a fluid of greater specific gravity ! 
The cause is worthy of consideration, 
because, as boats and marine vessels in 
general are of great importance to man, 
deductions and inferences may arise from 
its explication, of considerable practical 
utility. The ship-builder and the na- 
vigator may avail themselves of it ina 
way which I cannot hastily anticipate ; 
and the principle may, in various re- 
Spects, prove of consequence to mankind, 
In brief then: a boat, or ship, the ma- 
terials of which are specifically lighter 
than water, sinks when a hole is made in 
at below the water, by the pressure of the 
parts of the vessel which ure out of or 
above the water, upon the parts which are 
anmersed. 
This principle being understood, nu- 
merous practical inferences flash on the 
mind; and I shall briefly state those 
which at this moment occur to me, 
1. When a ship ,springs a dangerous 
leak, the true way to prevent her sink- 
dng is to diminish her height, and vo- 
Juntarily sink all that is possible of her 
bulk in the water. Whatever belongs 
to her which is specifically lighter than 
water, should be cast over-board, with- 
out being detaciied from the ship’s body. 
The masts should be cut away and fas- 
tencd along-side, on or under the water. 
Every thing should be removed whith is 
Hints for preventing Ships, Kc. from Sinking. 
30% 
above the level of the deck; and, if spe- 
cifically lighter than water, should be . 
fastened to the sides, in, or under the 
water, The very crew should immerse 
their bodies to their chins, and nothing 
should be allowed to remaim above the 
surface that,can be conveniently im~ 
mersed. Ofcourse, a3 much iron-work, 
and other bodies specifically heavier 
than water, as possible, should be de- 
tached and thrown over-board. By due 
attention to this principle, I should pre- 
sume, a@ priori, that no ship could founs 
der simply from a leak, or from filling 
with water, 
2, With respect to a boat, the prin- 
ciple is the same. If a boat springs a 
leak, or from any ether cause fills with 
water, the passengers should instantly he 
down, and keep nothing but their faces 
above the water. Every thing heavier 
than water should be thrown overboard, 
and nothing be allowed to stand above 
the level of the water, or on the top of 
the boat. 
8. By attending to the same prin- 
ciple, persons may often avoid being 
drowned. The total of the human body, 
in vital act+on, is specifically lighter than 
water; a living human body therefore 
will swim in water, provided it is not 
sunk by parts of 1t being protruded above 
the water, which unimmersed parts force 
down the parts under the water, till the 
internal cavities fill, If a person who 
falls into water, holds his breath, till, by 
the laws of specific gravity, he rises again 
to the surface, and then protrudes no part 
of his body above the surface besides his 
face, he cannot sink again. But the 
weight of his arms alone, if protruded 
out of the water, or even the entire of 
his head, without appropriate action, 
will be sufficient to sink him.  Slcn ave 
drowned, and all animals swim, when 
thrown into water; simply because men 
are able to raise their fore-linbs above 
their heads, and animals are not able to 
do so. The anunal stoks to the Jevel 
ascertained by his own specific gravity, 
and that of the fluid, which leaves per- 
haps nothing but his nose above the 
water; and then, to regain the shore, he 
exerts the same action with his limbs as 
he does in walking. If men were to vee 
main passive, keep down their hands, 
trust to the laws of specific vravity, and 
put themselves in the attitude of 
lng, the same results, and the 
curity, would, uy general, be 
sequence, Savaves swim from 
fancy on the same principie; 
of! waike 
saine Se- 
the con- 
their in- 
and civie 
lized 
