Sea Log and Sounding Machine . 119 
tom, the rotator will be in the position of the dotted 
lines y. 
This machine, simple in its construction, and scarcely 
more liable to accident than the common lead, ascertains, 
with the utmost precision, the perpendicular depth, by the 
mere act of descent through the water. No mistake can 
arise from that common source of error, the drift or lee- 
way of the ship during the time of descent; nor does an 
operation of such importance depend upon the uncertain 
sensation caused by the lead striking the bottom, on 
which the accuracy of the common log altogether de- 
pends, and which, it is well known, frequently and ma- 
terially misleads the best seamen : for though a thousand 
fathoms of line were paid out, in the smallest depth of 
water, no inaccuracy could arise, as the perpendicular 
depth, at the point of heaving, would be registered on 
the index. The only inconvenience experienced would 
be the additional labour necessary for hauling in the ex- 
cess of line. The most inexperienced persons may use 
this machine, without risk of error, in the most turbulent 
sea, and during the night. 
The advantages already enumerated would render the 
sounding machine of great importance; but there are 
other properties of still more consequence. 
To heave a ship to, in order to obtain soundings, on a 
lee shore, in stormy weather, is a very disagreeable ope- 
ration, attended with much trouble, and loss of way; 
also with considerable danger to the ship’s sails; indeed, 
it would often, under such circumstances, be attended 
with great hazard to the safety of the ship. To avoid 
these unpleasant consequences, the master sometimes 
adopts a measure, which he conceives to be the less ex- 
ceptionable alternative, by running on without sounding 
at all. 
