cxlvi 
APPENDIX. 
daily drift has been the point of the compass directly opposite to that of the 
wind, whether the latter was from the northward or the southward. It ap- 
pears to me, upon the whole, that the southerly current which we have here 
been enabled to detect, is not more than may be caused by the balance of 
northerly winds, added to the annual dissolution of large quantities of snow, 
which finds the readiest outlet into the Atlantic. 
In the Polar Sea, to the westward of Barrow’s Strait, no current has been 
found to exist, beyond that which is evidently occasioned by the different 
winds. In every part which we had an opportunity of visiting, the tides, 
though small, appear to be as regular as in any part of the world. 
The usual mode of trying the set and velocity of currents, by mooring a boat 
to a loaded iron-pot let down to a considerable depth under water, would 
appear to be a very unsatisfactory one. Major Rennell, in the course of his 
researches on this subject, has found that the Lagullus current to the south- 
ward of the Cape of Good Hope, is checked from a W. by S. course to S. W. 
by the banks of the same name, on which, in that part, the depth of water is 
one hundred fathoms or more ; as the current advances, the repeated checks 
turn it more and more southward, so that it afterwards runs nearly south, 
though the depth of water increases. It is not easy, therefore, to say how low 
such a current may extend, and to what depth the iron-pot must be sunk, in 
order to ensure its not drifting with the boat which it is intended to moor. It 
may be better, indeed, to try the current in this way, when in deep water, 
than not to try it at all, but it is evident that a considerable current may 
exist, when none can thus be detected. 
When the water is smooth and moderately deep, perhaps under 200 
fathoms, the tide or current is satisfactorily ascertained by a small boat 
moored to the bottom by a heavy deep-sea lead, or by the deep-sea clamms, 
an instrument invented by Captain Ross, for bringing up substances from the 
bottom. This mode was always adopted when practicable, in the course of 
this voyage. 
W. E. P. 
