354 On the use of the Dynamic Multiplier. 
lantic, that on entering upon soundings in the English Channel, he 
has found an increase of temperature in the water of 2° Fahrenheit. 
Those who differ from our views in regard to these currents, ought, 
therefore, to propose some by pothesis which will account for the ex- 
traordinarily low temperature of the waters which lave the Atlantic 
coast of the United States. Were these waters derived as an eddy 
current from the Gulf Stream, it is probable that they would no longer 
serve for the myriads of codfish which now frequent our shores, and 
which appear to inhabit the coldest waters. 
Many experiments upon the drift of currents have been made 
with bottles containing memoranda of the date and. locality in which 
they were committed to the sea. These experiments are not with- 
out their value, although it is obvious that a circuitous course is lia- 
ble to be construed into a direct one, and that violent winds may 
creatly affect the course of such objects upon the surface of the 
ocean, while an important diversion may also result from a superfi- 
cial cross current, as we have already noticed in the case of the Gulf 
Stream. Perhaps the suspension of some suitable weight to these 
floating messengers, with a line from five to twenty fathoms in length, 
would afford results of a more satisfactory character ; although the du- 
ration of such pendulous fixtures can hardly be relied on. If fitted in 
this manner, the fact should be noted upon the memorandum inclosed, 
which should specify also the length of line which may be attached. 
A full knowledge of the general system of currents in every ocean 
is obviously of great value to the nautical profession, and is important, 
also in its relations to physical science. It is hoped, therefore, that 
these considerations will prove sufficient to stimulate our navigators to 
make and record the necessary observations, and to promulgate the 
same through the proper channels of information. 
Arr. XX.—On the use of the Dynamic Multiplier,* with a new 
accompanying apparatus ; by C. G. Pacu, M. D. 
Tue multiplier used in these investigations is composed of three 
hundred and twenty feet of copper ribbon, one inch wide, woun 
