OP TID'ES. 



effusions, which produce on our coast two fluxes and two refluxes 

 nearly in the same time that the sun, making the circuit of the globe, 

 alternately heats two continents and two oceans, that is, in the space 

 of twenty-four hours, during which his influence twice acts and is twice 

 suspended ; nor shall I speak of the retardation, which is nearly three 

 quarters of an hour every day, and which seems regulated by the 

 different diameters of the polar cupola of ice, whose extremities, 

 incited by the sun, diminish and retire from us every day, and 

 whose effusions must consequently require more time to reach the 

 line, and to return from the line to us. Nor shall 1 dwell on the 

 other relations these polar periods have to the phases of the moon, 

 especially when she is at full ; for her rays possess an evaporating 

 heat, as the late experiments at Rome and Paris fully demonstrate ; 

 much less shall 1 involve myself in a discussion of the tides of the 

 south pole, which in summer in the open sea come in vast surges 

 from the south and the south west. There are two tides every day ; 

 because the sun warms by turns, every twenty-four hours, the east 

 and west side of the pole in fusion. Precisely the same effect takes 

 place in lakes situated in the vicinity of icy mountains, which have 

 a flux and reflux in the day-time only. But it cannot he doubted 

 that, if the sun warmed, during the night, the other side of these 

 mountains, they would produce another flux and reflux ; and con- 

 sequently two tides in twenty hours, like the ocean. 



We are not to imagine that every tide is a polar effusion of the 

 particular day on which it happens, but an effect of the series of 

 polar effusions; so that the tide which takes place on our coasts 

 to-day, is perhaps part of that which took place six weeks ago. 

 But here, too, must we admire the harmony of nature : the even, 

 ing and morning tides take place on our coasts as if they issued that 

 very day from the higher and lower part of our hemisphere ; and 

 the tides of summer are precisely opposite to the tides of winter, as 

 are the tides from whence they flow ; our evening tides in summer, 

 and our morning tides in winter, being greatest. 



If the tides are stronger after the full moon, it is because that 

 luminary increases by her heat the polar effusions, and consequently 

 the quantity of water in the ocean, 



Let us now, continues M. St. Pierre, explain why the tides of the 

 South sea do not resemble those of the Atlantic ocean. The irregular 



