DE FLUXU ET REFLUXU MARIS. 243 



favoleggiare gli scrittori con molte vane fantasie.&quot; No 

 refutation of a theory which altogether misrepresents 

 the facts which it proposes to explain could ever have 

 been needed ; but the advance of mechanical science 

 has long since made it easy to show that no reciprocat 

 ing motion of the waters of the sea could be produced 

 in the manner described by Galileo. 



Bacon does not mention Galileo s theory in the pres 

 ent tract, which was therefore probably written before 

 or not long after 1616. But in the Novum Organum 

 [11. 46.] it is mentioned and condemned ; one ground 

 of censure being that it proceeds on the untenable hy 

 pothesis of the earth s motion, and the other that the 

 phenomena are misrepresented. 



Bacon, both in this tract and in the Novum Orga 

 num, ascribes the tides in the Atlantic to a derivative 

 motion of the waters, caused by the obstacles which 

 the form of the continents of the old and new worlds 

 oppose to its general westerly movement. It is thus 

 that he meets the objection which would arise from the 

 circumstance that there is high water at the same time 

 on corresponding points of the shores of Europe and 

 America. This notion of a derivative tide is absolutely 

 necessary in the detailed explanation of the phenom 

 ena, and I am not aware that any one had previously 

 suggested it, at least in the distinct form in which Ba 

 con puts it. He admits that, if the tides of the Pacific 

 synchronise with those of the Atlantic, his theory that 

 the tides depend on a progressive motion of the ocean 

 must be given [up] . If it be high water on the shores 

 of Peru and China at the same hours as on those of 

 Florida and Europe, there are no shores left on which 

 there can then be low water. For the important ob- 



