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- Art. VIII. On the Soundings in the British Channel. 
[To the Editor of the Quarterly Journal. 
Sir,—A paper has been lately read at the Royal Irish Academy 
by Mr. A. Nimmo, civil engineer, containing the ingenious idea 
that the various coloured sands, shells, and ooze found at the bot- 
tom of the sea, in the chaps of the Channel, are the terminations 
of beds of granite, limestone, coal, §c., which dip from various 
parts of Great Britain and Ireland, and to which they may be sa- 
tisfactorily traced. 
This idea, if properly pursued, would materially assist in classi- 
fying the soundings in our Channel charts. It is needless to insist 
upon the great importance of a correct projection of those sound- 
ings ; in conjunction with the depth of the water, they are frequently 
the only means that the seaman possesses, in thick weather and 
long nights, of ascertaining his position ; and it is too well known 
that the most part of the soundings in both the channels, and the 
whole of them on the great western bank, are laid down on our 
present charts in a manner that is altogether disgraceful to the 
age. No uniform means have ever been taken to amend them; 
they are miserable compilations, or copies of each other, and the 
few correct soundings that have been here and there interpolated, 
instead of serving as standard points to adjust the rest, actually 
increase the general confusion, 
The Admiralty has for some time very judiciously employed Mr. 
Tiarcks in determining the longitudes of several interesting places, 
by the mean of a multitude of chronometers. Would not a similar 
method, devoted, for a few summers, to the construction of an en- 
tirely new chart of these banks, be one of the most essential benefits 
that could be conferred on the navigation and commerce of our 
home seas ? 
A frigate or other convenient ship might carry the necessary 
instruments and chronometers, while the soundings should be 
taken by tenders, or in fine weather, and particularly in strong 
tides, by boats. The ship should go sufliciently off the wind to avoid 
