THE EARTH. 221 



places, and in our own seas in particular, the 

 greatest swell of the tide is not while the moon 

 is in its meridian height, and directly over the 

 place, but some time after it has declined from 

 thence. The sea, in this case, being obstructed, 

 pursues the moon with what dispatch it can, but 

 does not arrive with all its waters till long after 

 the moon has ceased to operate. Lastly, from 

 this shallowness of the sea, and from its being 

 obstructed by shoals and straits, we may account 

 for the Mediterranean, the Baltic, and the Black 

 Sea, having no sensible tides. These, though to 

 us they seem very extensive, are not however 

 large enough to be affected by the influence of 

 the moon ; and as to their communication with 

 the ocean, through such narrow inlets, it is im- 

 possible that in a few hours' time they should re- 

 ceive and return water enough to raise or de- 

 press them in any considerable degree. 



In general, then, we may observe, that all tides 

 are much higher, and more considerable in the 

 torrid zone, than in the rest of the ocean ; the sea 

 in those parts being generally deeper, and less af- 

 fected by changeable winds, or winding shores.* 

 The greatest tide we know of, is that at the 

 mouth of the river Indus, where the water rises 

 thirty feet in height. How great, therefore, must 

 have been the amazement of Alexander's soldiers 

 at so strange an appearance 1 They who always 

 before had been accustomed only to the scarcely 

 perceptible risings of the Mediterranean, or the 



* Buffon, vol.ii. p. 187. 



