RIVERS. 293 



brilliant capital, with all its sumptuous palaces, into a chaotic mass of ruins. We 

 have the materials of this statement from M. Kohl. The Gulf of Finland runs to a 

 point as it approaches the mouth of the Neva, where the most violent gales are always 

 those from the west ; so that the mass of waters on such occasions is always forcibly 

 impelled towards the city. The islands forming the delta of the Neva, on which 

 St. Petersburg stands, are extremely low and flat ; and the highest point in the city is 

 probably not more than twelve or fourteen feet above the average level of the sea. A 

 rise of fifteen feet is therefore enough to place all St. Petersburg under water, and a rise 

 of thirty feet is enough to drown almost every human being in the place. Hence the 

 inhabitants of the capital are in constant danger of destruction at the period referred to, 

 and can never be certain that the 500,000 of them may not, within the next twenty -four 

 hours, be driven out of their houses, to find, in multitudes of instances, a watery grave. 

 This is not a chimerical danger ; for, during its short continuance, the city of the Czar 

 has experienced some formidable inundations. The only hope of this apparently doomed 

 city is, that the three circumstances may never be coincident, namely, high water, the break- 

 ing up of the ice, and a gale of wind from the west. It is nevertheless true, that the 

 wind is very often westerly during spring, and the ice floating in the Neva and the Gulf 

 of Finland is of a bulk amply sufficient to oppose a formidable obstacle to the egress of 

 the water ; so that it will not be surprising if St. Petersburg, after suddenly rising like 

 a meteor from the swamps of Finland, should still more suddenly be extinguished in 

 them. 



The periodical rise of rivers is either diurnal, semi-annual, or annual, and proceeds 

 from a variety of causes. Where streams descend immediately from mountains covered 

 with snow, the heat of the sun melting the snow produces high water every day, the 

 increase being the greatest in the hottest days. In Peru and Chili there are small rivers 

 which flow only during the day, because they are fed entirely by the melting of the snow 



Valley of the Concon, Chili. 



upon the summit of the Andes, which takes place only when the solnr influence is in 

 action. In Hindustan, and some parts of Africa, rivers exist, which, though they flow 

 night and day, are, from the accession of snow-water, the greatest by day. Those rivers 

 also which fall into the sea have their level daily varied by the tidal wave for some 

 distance from their mouths, the extent through which the influence of the tides is felt 

 being modified by the breadth and shape of their channels and the force of their current. 

 The wider and more direct the bed of a stream communicating with the ocean, and the 



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