84 THE REV. W. WHEWELL'S RESULTS OF TIDE OBSERVATIONS. 



the details by which these results are established till I am able to include in them 

 the east coast of England and the coasts of Ireland and Scotland. 



1. In the first place I will observe, that I am convinced from the examination 

 which I have given to the subject, that observations made in this manner may be 

 depended upon for many extensive and important inferences. The returns of last 

 June are more consistent and accurate than I could have anticipated. I have reason 

 to believe that in much the greater part of the cases they were made with care and 

 fidelity, and in many instances with ingenious and suifable contrivances. It is im- 

 possible not to take the opportunity of saying that they reflect great credit both 

 upon the intelligence and the punctuality of the officers and men of the coast-guard 

 service. 



2. One of the reasons for wishing to obtain such simultaneous tide observations, 

 was the hope of ascertaining by this means whether there are general irregularities 

 which affect the tides at all places along an extensive line of coast. Such irregu- 

 larities are beforehand very conceivable. The tide-wave which visits our coasts has 

 been propagated up the Atlantic, and influenced at least, if not produced, by the tide 

 of the Antarctic Ocean. If the causes which determine the velocity of this wave 

 could in any case so far vary as to make it an hour behind its time in the Atlantic, 

 that one tide would at all our ports take place an hour later than the regular time ; 

 and the existence of an influence of this kind would be detected by such an anomaly 

 appearing in the observations of the whole or a large portion of the British coast. 



I think I may venture to say that no such general irregularity affected any of the 

 tides from the 7th to the 22nd of last June. Partial anomalies of greater or less 

 extent occur in the observations, but nothing which can be considered as being of a 

 general character, and indicating a distant origin, like what has been spoken of. 



This result is, I conceive, important ; for it appears to render it probable that we 

 may, with care and perseverance, make our mathematical prediction of the tune of 

 the tide much more accurate than we might otherwise have hoped. Since the tide 

 is not affected by distant and general irregularities, it is irregular only so far as it is 

 influenced by causes which operate in the neighbourhood, and vary from one place 

 to another ; as, for instance, the eff'ect of the wind in connexion with the form of the 

 land. Now, not only will irregularities arising from such causes disappear in the means 

 of long series of observations, but where such mean results have been obtained, the 

 effiect of the disturbing causes (as, for instance, the wind blowing at and near the 

 place,) may be determined empirically. We should thus have a local meteorological 

 correction to apply to the prediction of the tide, in addition to the astronomical cor- 

 rections ; our tide tables would be much improved, and our knowledge of the tides 

 rendered more correct and complete. 



3. My examination of the results of the observations of the time of high water has 

 been conducted for the most part by the method already so often employed by 

 Mr. Lubbock ; namely, by erecting a series of equidistant ordinates to represent the 



