NATURE GOVERNED BY GENERAL LAWS. 



the atmospheric phenomena which will take place on that day. 

 The doubt and uncertainty which attend these events belong 

 altogether to our anticipations of them, and not to the things them- 

 selves. If our knowledge of meteorology were as advanced as our 

 knowledge of astronomy, we should be in a condition to declare 

 the time, duration, and intensity of every shower, which shall 

 fall during the ensuing year, with as much certainty and precision 

 as we are able to fortel the rising, setting, and southing of the 

 sun and moon, or the rise and fall of the tides of the ocean. 



3. If our knowledge of the laws which govern the movements 

 of the aerial ocean which floats above the crust of the earth be 

 obscure and imperfect, it is infinitely more so of those which rule 

 the matter which lies below that crust. Yet what various and 

 apparently different and unconnected phenomena are governed by 

 these undiscovered laws, which, through ignorance of them, have 

 been regarded as arising from local, accidental, and totally inde- 

 pendent and different agencies. Earthquakes, volcanic eruptions, 

 the production and submersion of islands, the issue of gases such 

 as sulphurous and carbonic acid from fissures in the earth, hot 

 springs, eruptions of warm mud, the increase of temperature at 

 increasing depths, the origin of mountain chains, such as the 

 Andes, the Pyrenees, the Alps, and the Himalaya, the alternate 

 elevation and submersion of vast continents, the variations of the 

 configuration of the land, and the distribution of the waters on 

 the surface of the globe, all these so apparently different phe- 

 nomena, it has been the triumph of science to trace to a common 

 origin, the reaction of the matter confined within the earth against 

 its external shell. 



4. It is our present purpose briefly to explain the physical con- 

 ditions out of which these stupendous phenomena arise, and to 

 describe the characters and circumstances which attend them. 

 With this view, it will be necessary first to state what is known, 

 either by observation or inference, respecting the condition of that 

 part of the earth included within the solid shell, the external 

 surface of which is the habitation of the human race, and other 

 organised tribes, and to explain generally what have been at past 

 epochs and at the present time the chief effects produced by the 

 reaction of the matter thus confined upon the crust which 

 encloses it. 



When it is considered that the actual distance of the surface 

 from the centre, or the length of the terrestrial radius, is more than 

 twenty millions of feet, and that the utmost depth to which we 

 have been able to descend in boring or mining operations has 

 not much exceeded two thousand feet, that is the ten-thousandth 

 part of the entire radius, it will be apparent that the data 



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