View of Mr, Wheweirs Researches on the Tides, 353 



lines of the coasts of Europe, accompanied also by indications, ef- 

 fected by a peculiar notation, of the total range, in yards, of the tides 

 at the different stations at which observations had been made. 



Many very remarkable conclusions with respect to the motion of 

 the tide-wave have resulted from these observations; amongst 

 others may be mentioned the rotatory motion of the tide-wave 

 which enters the German Ocean between the Orkneys and Norway, 

 sends a southerly detachment along the coasts of Great Britain, 

 which is reflected from the projecting coast of Norfolk upon the 

 north coast of Germany, and meets the main wave again on the 

 coast of Denmark. 



It is impossible in the course, of a very brief abstract like the 

 present to Jiotice ill Mi: Whewell's researches in detail. His 

 second great object was to compare the observed laws of the tides 

 with the theory, or to propose such modifications of the forms of 

 the theory as would reconcile it with the observations. 



The interest which attaches to such investigations, which is so 

 great during the progress of the structure which is to be raised upon 

 them, ceases in many cases when the fabric is completed : a remark 

 which is applicable to many of the most important researches and 

 discoveries in philosophy, where we are accustomed to regard the last 

 form only in which the theory is compared with the facts which are 

 observed, and to forget or to neglect the series of laborious in- 

 vestigations which have led to its establishment, but which are no 

 longer necessary for its explanation or proof. This observation 

 may be applied, in some degree, to Mr. Whewell's very ingenious 

 Memoir " On the Empirical Laws of the Port of London", in which 

 he attempts to deduce from observation and from very simple ge- 

 neral considerations, the character of the formulae for determining 

 the establishment, the semimenstrual inequality, the corrections for 

 lunar and solar parallax and declination, both as affecting the times 

 and the height of high water. Similar observations may be ex- 

 tended to his papers on the " Empirical Laws of the Tides of the 

 Port of Liverpool," and also on the " solar inequality and diurnal 

 inequality" of the tides at the same place, which are full of valuable 

 suggestions which the subsequent investigations of Mr. Lubbock 

 have, in some cases, very remarkably confirmed and extended. 



The last of the series of researches of Mr. Whewell relate to the 

 diurnal inequality of the height of the tide, which the discussion of 

 the tides at Liverpool had exhibited, though under circumstances 

 much less striking than those which characterize its appearance in 

 other places. The first of his memoirs on this subject relates to the 

 diurnal inequality at Plymouth and Sincapore, at the last of which 

 places its magnitude is very remarkable, making a difference of not 

 less than six feet in the height of morning and eveiringtide, and quite 

 sufficient to obliterate, under certain circumstanc 2s, one of the semi- 

 diurnal tides, and explaining certain phaenome^a in the tides which 

 have been considered as cases of interference. Mr. Whewell was 

 led, from certain remarkable changes in the epoch of this phaeno- 

 menon, which seemed to be deducible from the observations at Bris- 



Fhil. Mag. S. 3. Vol. 12. No. 75. April 1838. 2 K 



