THE NORTH SEA AND ENGLISH CHANNEL. 
707 
Referring then to these observations, and taking them in the order in which the Comparison 
light-vessels are placed with respect to the progress of the tide-wave, we shall have 
the intervals between the turn of the stream at those places, and the time of high 
water at Dover (the standard), as follows : — 
At the Newarp L.V., the stream is slack twenty-two minutes before Dover. 
At the Cockle L.V., the stream is slack at the same time as Dover. 
At the Stanford L.V., the stream is slack nine minutes before Dover. 
At two stations nearer Dover, the stream is slack twenty-four minutes after. 
At the Shipwash L.V., the stream is slack twenty-four minutes after. 
At the Galloper L.V., the stream is slack the same time as Dover. 
At the Kentish Knock L.V., the stream is slack nine minutes after Dover. 
Lastly, off the North Foreland, the stream is slack the same time as Dover. 
Between these stations and the meridian of 3° 0' E. we find the following in- 
tervals. 
In the parallel of Cromer, twenty-four minutes before Dover ; at the next station, 
southward, twenty-four minutes after ; at the next, four minutes after ; then, thirty- 
six minutes after ; at the next, nineteen minutes after ; at the next, three minutes 
after; and lastly, off the North Foreland, the same time as Dover. 
In the first set of comparisons the differences are not greater than might be attri- 
buted to the ordinary irregularity of the tides ; in the second we discover a progressive 
increase, and then the phase of the stream seems to be inverted, until at the end of 
the series we find the interval vanish, and the stream to turn with the high water 
on the shore. 
To the eastward of 3° of longitude, the times of slack water get considerably later Retardation 
in that part of the Channel which lies between the northern limit of the Thames and 
the Texel, and the phase of the stream in all this portion of the North Sea appears to towards the 
be inverted ; the intervals also to get longer as the Dutch coast is approached. 
The occurrence of this inversion of the phase of the stream with the inversion of 
the phase of the establishments on the coast of Holland, and its position occupying 
the site of the node of the tide in Professor Whewell’s chart of cotidal lines, is a 
coincidence which ought not to be overlooked, although I am not able to discover 
any connection between the phenomenon, which is evidently the cause of the unusual 
retardation of the stream above-mentioned, and the phenomena of the cotidal 
chart. 
There seems to be very little doubt that the retardation of the stream, and the con- Cause of the 
sequent inversion of phase now noticed in all this part of the Channel, is entirel}’^ onhe^turn 
owing to the outer stream setting round the Texel, at a time when the stream is slack of the stream 
in all other parts of the Channel and preparing to go round*. corst^of Hol- 
An inspection of the Plan for one hour after high water will clearly show this to land, 
be the case ; it will there be seen that the stream of the Channel is making an effort 
* See Chart one hour after high water, Plate XXXIII. 
