APPENDIX. 279 



been siinilarl}^ perplexed, I could have little doubt, having often 

 talked to experienced practical men on the subject. Probably the 

 expressions ' tide and half-tide,' ' tide and quarter-tide,' &c., con- 

 veyed more distinct ideas to their minds, than to mine : for to me 

 they were unsatisfactory, and although quite aware of their meaning, 

 I never liked them. From 1833, I and my companions on board 

 the Beagle paid more attention to the subject, and made obser- 

 vations in the manner suggested by Mr. Whewell, as often as our 

 other avocations allowed. It was, however, impossible to take interest 

 in the subject, and discover difficulties, facts irreconcileable to theory, 

 without trying to think how to account for them — unquaHfied even 

 as I knew myself to be for such a task.* Perhaps I was encouraged 

 to meditate by Mr. Whewell's concluding paragraph ; f and, sepa- 

 rated from assistance, I tried to reason my way out of the dilemma, 

 by the help of such few data as I could dwell upon vpith certaint}^ 



* Among the points which I could not establish in my own mind, by 

 appeal to facts, were — " the tides of the Atlantic are, at least in their 

 main features, of a derivative kind, and are propagated from south to 

 north." (p. 164.) "That the tide. wave travels from the Cape of Good 

 Hope to the bottom of the Gulf of Guinea, in something less than four 

 hours." (p. 167.) " That the tide-wave travels along this coast (American) 

 from north to south, employing about twelve hours in its motion from 

 Acapulco to the Strait of Magalhaens." (p. 194.) " From the compara- 

 tive narrowness of the passage to the north (of Australia), it is almost 

 certain that these tides must come from the southern side of the conti- 

 nent." (p. 200.) " The derivative tide which enters such oceans (North 

 and South Pacific) from the south-east, is diffused over so wide a space, 

 that its amount is also greatly reduced." (p. 217.) &c. 



t " I cannot conclude this memoir without again expressing my entire 

 conviction of its very imperfect character. I should regret its publication, 

 if I supposed it likely that any intelligent person could consider it other- 

 wise than as an attempt to combine such information as we have, and to 

 point out the want and the use of more. I shall neither be surprised nor 

 mortified, if the lines which I have drawn shall turn out to be, in many in- 

 stances, widely erroneous : I offer them only as the simplest mode which 

 I can now discover of grouping the facts which we possess. The lines 

 which occupy the Atlantic, and those which are near the coasts of Eu- 

 rope, appear to have the greatest degree of probability. The tides on the 

 coasts of New Zealand and New Holland, have also a consistency which 

 makes them very probable. The Indian Ocean is less certain ; thougli 

 it is not easy to see how the course of the lines can be very widely diffe- 

 rent 



