220) PHYSICS. 
and in Stockholm nineteen inches. In the mountains of Norway, which 
have a very different climate, and are celebrated for their copious rains, 
the annual fall amounts to eighty-three inches. At* Mahabuleshwar in 
India, on the western slope of the Ghauts, it is 283 inches, at Matouba on 
the Island of Guadaloupe 274, at Basseterre on the same island and at 
Anjarakandy in the East Indies 116, at Coimbra in Portugal 111, on the 
Isiand of Granada 105, in St. Domingo 101, at Havana 86, on the coast 
of Sierra Leone 81, at Bombay 734, at Calcutta 71, and at Rio Janeiro 
56. From these data we perceive that only a few places within the 
tropics exhibit a greater quantity of rain than mountains. The average 
number of rainy days, by which we understand all on which rain occurs 
of whatever duration, increases in Europe from south to north, amounting 
in southern Europe to 120, in central Europe to 146, and in northern 
Europe to 180; at Buda 112, at Warsaw 138, in Germany about 150 
(Carlsruhe 174, Tegernsee 170, Munich 149, Stuttgardt 127, Ratisbon 
115), about the same in England, France, and the Netherlands (Rotterdam 
187, Paris 160, Poitiers only 99, at St. Petersburg 168, at Moscow 205, 
&c., &c). 
The distribution of rain throughout the year varies much in different 
countries ; in central Europe, which has a continental climate, summer 
rains have the preponderance, while in southern Europe this belongs to the 
winter and autumn. On the west coast of England the winter rains are 
more considerable than the summer, while in the interior this condition of 
things is just reversed. In the western parts of Scandinavia the winter 
rains are very copious, in Sweden they are almost entirely wanting, so that 
this country exhibits a transition from a sea to a continental climate so 
rapid as to have nowhere else its parallel. The rain of the warm seasons 
of the year is generally the most copious. Thus, taking the rain falling on 
a winter's day as unity or one, the amount falling in summer will be 
indicated in the following mean quantities: in England, 1.07; western 
France, 1.08; central France, 1.57; Germany. 1.76; St. Petersburg, 2.17. 
The preponderance of the summer rain is thus seen to increase as we go east. 
In England and on the coast of France the average fall of rain on the 
autumnal rainy day amounts to two lines and three quarters for the former, 
and two lines and a quarter for the latter ; in central France a summer’s rain 
is about 2.41, in Germany 2.33, and in St. Petersburgh 1.67 lines. The same 
laws, with respect to the predominance of coast rains in winter and central 
rains in summer, appear to apply also to other parts of the world. 
Rain-water collected after a considerable amount has fallen, is almost 
chemically pure, and may be used in many cases instead of distilled water ; 
yet it frequently contains slight amounts of certain mineral substances, 
especially chloride of sodium, generally combined with some lime. Traces 
of a somewhat greater quantity of salt are observed only on the coast and 
a slight distance from it, although most of the watery vapor contained in 
the atmosphere has ascended from the sea. Cases not rarely occur where 
various substances from the animal, vegetable, or mineral kingdom, either 
alone, or more frequently mingled with rain or snow, appear to have fallen 
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