206 EBB AND FLOW. 



Let it be inquired, whether the hour of the tide on the 

 coast of Brazil be before the hour of the tide on the coast 

 of New Spain and Florida ? 



Let it be inquired, whether the hour of the tide at the 

 shores of China is not foun d nearly the same with the hour 

 of tide on the coast of Peru, and with the hour of reflux 

 on the coast of Africa and Florida ? 



Let it be inquired, how far the hour of tide on the coast 

 of Peru differs from the hour of tide at the coast of New 

 Spain ; and particularly what are the differences of the hour 

 of tide at either shore of the Isthmus of Darien, in America ; 

 again, how far the hour of tide on the coast of Peru corres 

 ponds with the hour of tide on the coast of China ? 



Let it be inquired respecting the largeness of the tides 

 on different coasts, not merely respecting their periods or 

 hours. For although the largeness of tides is generally 

 caused by the depressions of the shores, yet notwithstand 

 ing they are closely connected with the true principle of the 

 motion of the sea, according as it is favourable or adverse. 



Let inquiry be made with respect to the Caspian sea, 

 which is formed by considerable bodies of water locked up 

 without any outlet, into the ocean, if they are subject to 

 ebb and flow, and what? our conjecture being that the 

 waters of the Caspian Sea may have one tide a day, not 

 two, and such that the eastern shores of it are deserted by 

 the sea, while the western are overflowed. 



And let inquiry be made, whether the increase of the 

 tide at new and full moons and at the equinoxes, takes 

 place at the same time in different parts of the world (and 

 when we say at the same time, we do not mean at the same 

 hour, for the hours vary, according to the rapidity of the 

 waters motion towards the shores as we have said), but in 

 the same day. 



Limits. The inquiry is not extended to a full explana 

 tion of the harmony of the monthly motion of the sea with 

 the moon s motion, whether that takes place from a subor 

 dinate or a joint cause. 



Relations. The present inquiry is connected with the 

 inquiry whether the earth revolves with the diurnal motion 

 of the heavens. For if the tide is, so to speak, the last 

 stage of the gradual diminution of the diurnal motion, it 

 will follow that the globe of the earth is immoveable, or at 

 least that its motion is slower by far than that of the waters. 



W. G. G. 



