134 S. R. Elson — Currents and Tides of the Hugli. [Nov., 



and courteously placed at my disposal by the Port Officer, Captain Stiffe, 

 I. M.) of currents, that the mean daily set of the sea for the year 1880 was, 

 at the Mutlah Light Vessel, 12*1 miles W. f S., and, at the Eastern Channel 

 Light, only one-half, or 6*4 miles in a S. W. by W. f W. direction ; 

 whilst at the Pilots' Ridge, 32 miles W. S. W. of the latter, it was 

 really an inset of the sea of f of a mile N. W. f W. per diem, during 

 the six months, March to September, that she was in position. 



Besides the natural tendency of the waters of the Hooghly littoral to 

 flow round over the sands cyclonically^ or against the hands of the watch 

 (face upwards), all the year round, any small baric depression out over 

 the Bay is quite sufficient to hurry it along with great force ; so that it is 

 a well-known fact that a large westward set at the Pilot Station, Sand- 

 heads, is a sure precursor of a cyclonic storm of greater or less intensity ; 

 this set showing itself long before the indraughted N. E. wind has gained 

 sufficient force to cause it by friction with the sea-surface ; doubtless, 

 this deep gut, so handy to draw upon, furnishes a ready supply of 

 northwards moving water, as required by the demand of a reduced or 

 diminished aerial pressure on its left front ; as flow also the responsive 

 and light, but much more sluggish, air strata above it : a vibration 

 of energy being taken up and translated by a water medium four and 

 a quarter times more surely and speedily than by an air medium. 



On the other hand, when such local meteorological conditions of 

 an anti- cyclonic character occur as take place at the head of the Bay 

 during the months of March, April, and May, (when strong S. S. W. 

 and S. W. winds blow, and an eastward set of the sea is begot), such 

 eastward set at the Mutlah Light is as nothing compared to that at the 

 Eastern Channel Light; and even here, is scarcely ever more than 

 12 miles in the 24 hours, and, then, only on extraordinary occasions, 

 when a S. W. gale and high sea call it forth (see Table of Sea-set at 

 Sandheads in author's Sandheads Sailing Directory) . 



This deep gut of (doubtless running) water, this Swatch of no 

 Ground, has also another influence not yet written about, that is, in 

 giving a greater range to the tides in the Mutlah River of 3 feet 6 inches 

 over those of the Hooghly River : these waters being so close-to are ever 

 ready to swing and pulsate, to flow and ebb, in response to the disturbed 

 equilibrium caused by the constantly varying attractions of sun and 

 moon on land and sea areas : whilst the Hooghly has to draw upon 

 a more distant reservoir wherewith to build up her tidal wave, and to 

 which also to return the uprisen waters after the Hooghly meridian has 

 rolled away eastwards from under the lunar and solar perturbating 

 influences. I have been told by the captains of the Light Vessels 

 who have had experience there, that there is a much stronger current 



