818 



He then takes a comprehensive view of the tidal system of the 

 English Channel and German Ocean together, and considering them 

 as one great canal open at both extremities to the free admission of 

 a great tidal wave, which might be supposed to meet and form a 

 combined or stationary wave (art. 187? Encyclopedia Metropolitana), 

 he infers that in such a case, there ought to be in the eastern half 

 of such a canal, a recurrence of the phenomena which had been 

 found to exist in the western half. He proceeds to explain that, 

 from a valuable series of observations in the German Ocean by Cap- 

 tain Washington, R.N., and other authorities, it does appear that, 

 inverting the direction of the stream, there is a correspondence of 

 phenomena in almost every respect: that the offing and channel 

 streams meet off Lynn, as off the Gulf of St. Malo, at the same hours, 

 and at the same distance nearly from the virtual head of the tide : 

 that the phase of the tide at Lynn corresponds with the phase of the 

 tide at Jersey : that there is an increased rise there also ; and that 

 from the meeting of the tides off Lynn to the meeting of the streams 

 off Dover, there is, as in the former case, a stream which turns nearly 

 simultaneously with the high and low water on the shore at Dover ; 

 the incoming and outgoing streams coinciding with the rising and 

 falling water there ; and that there is, in fact, a complete identity of 

 tidal phenomena in both parts of the supposed canal ; of this an 

 illustration is given in two plans. 



The author states that the meeting of the waves which enter the 

 canal at opposite points does not occasion a stationary point of per- 

 manent slack-water, but one wave alternately prevails, so that the 

 point of slack- water oscillates between Ramsgate and Hastings nearly, 

 and occasions an inversion of the stream at about two hours before 

 that of the true stream of the channel. He thinks it convenient for 

 the purposes of navigation to consider this an intermediate stream, 

 although in reality it is only a shifting of the place of the meeting 

 and divergence of the opposite channel streams. To illustrate this 

 part of the paper a table is given, in which the courses of the streams 

 in various compartments of the supposed canal are given at every 

 hour of the tide. 



The author thinks this system of tides sufficiently established for 

 the purposes of navigation, but with regard to the perfectly simul- 

 taneous motion of the stream throughout the stationary wave, he is 

 of opinion that nothing but simultaneous observations will be con- 

 sidered satisfactory to science upon such a point, and these -he hopes 

 will be supplied by the observations of the ensuing summer. 



The advantage of referring the motion of the stream to a standard 

 such as that of the Dover tide-table will, it appears, be sensibly felt 

 by the mariner, who will now have his course through the moving 

 waters of the channel rendered simple and plain, instead of being 

 perplexed with unsatisfactory references, and with calculations which 

 in too many instances, it is believed, have caused the set of the tide 

 to be wholly disregarded. 



The want of a standard to which desultory observations, made in 



