Mr. Lubbock's 'Elementary Treatise on the Tides. itQS 



not have been so soon undertaken, but for tlie interest felt in the 

 subject by some individuals distinguished in science, particularly by 

 Mr. Whewell, and but for the pecuniary grants which were in con- 

 sequence devoted to it by the British Association. 



Mr. Lubbock having been thus enabled to procure the valuable 

 assistance of Mr. E. Russell and Mr. Jones, the results have been 

 published by him in the Philosophical Transactions, as above inti- 

 mated; "but as he is not aware," he remarks, " that any detached 

 elementary Treatise on the Tides exists in the English or in any other 

 language," he trusts that a more connected view of the subject may 

 not be uninteresting. In the interest of the connected view of the 

 subject which Mr. Lubbock has taken, accordingly, in the work now 

 before us, every one must concur who is enabled to appreciate its 

 importance. 



The treatise commences with an historical notice of the inquiry 

 into the theory and laws of tidal phenomena, tracing it from Pliny 

 to Kepler and Wallis ; stating in succession the true theory as dis- 

 covered by Newton, and the researches of Bernoulli and Laplace, and 

 concluding with the remark, " The attention of Laplace does not 

 appear to have been directed to the construction of Tide Tables for 

 predicting the time and height of high-water at any port ; until very 

 recently, this practical solution of the problem was attempted only 

 in Great Britain." 



We next have the " Mathematical Theory of the Oscillations of 

 the Surface of the Ocean ;" which is succeeded by the "Comparison 

 of Theory with Observation," the "Method of predicting the Time 

 and Height of High-water," and copious and explicit directions for 

 making and recording "Observations of the Tides." 



We extract the following remarks on the relations of the subject 

 of the tides to various other branches of science which occur inci- 

 dentally, but which we conceive are of great interest. 



" The branch of the subject which appears at present to stand in 

 need of the most laborious exertions, is the accurate determination 

 of the semi-vienstrual inequality and the local constants (from which 

 the quantities (yi), D, (E) may be immediately obtained) for other 

 places than Liverpool and London. Until this is done, our know- 

 ledge of the progress of the tide-wave and of the circumstances 

 which attend it must be very defective. This question is not unin- 

 teresting to geologists, for, until it has been taken up carefully and 

 extensively, it will be impossible to detect slight changes in the re- 

 lative level of sea and land, except in narrow seas, such as the Bal- 

 tic, which are exempt from tides. Even to trace the gradual extinc- 

 tion of the semi-menstrual inequality between London and Tedding- 

 ton, or in any similar locality, would not be unprofitable." — Pref. p. v. 



"The great real obstacle to perfection in calculations m- predic- 

 tions of the tides consists in the fluctuations of the establishment. 

 Suj;pose the establishment (or tlie constant to be added to i|/) changes 

 a minute per annum, and that having determined it from ail the ob- 

 servations of twenty-one years, we proceed to employ it in calcula- 

 tions of the time of high water. It is obvious that if we calculate 



Phil, May, S. 3. Vol. 14. No. 91. Jme, 1S3?. 2 H 



