GEOLOGY. 



ON THE RECENT PROGRESS OF GEOLOGY. 



The following address, reviewing the recent progress of Geological 

 Science, was read by Sir Charles Lyell, on taking the chair, as Presi- 

 dent of the British Association, for 1864: 



Phenomena of Hot Springs. Dr. Daubeny, has remarked that 

 nearly all the most celebrated hot springs of Europe, such as those 

 of Aix-la-Chapelle, Baden-Baden, Naples, Auverne, and the Pyre- 

 nees, have not declined in temperature since the days of the Romans ; 

 for many of them still retain as great a heat as is tolerable to the hu- 

 man body, and yet when employed by the ancients they do not seem 

 to have required to be first cooled down by artificial means. This 

 uniformity of temperature maintained in some places for more than 

 2,000 years, together with the constancy in the volume of the water, 

 which never varies with the seasons, as in ordinary springs, the iden- 

 titv also of the mineral ingredients which, century after century, are 

 held by each spring in solution, are striking facts, and they tempt us 

 irresistibly to speculate on the deep subterranean sources both of the 

 heat and mineral matter. How long has this uniformity prevailed ? 

 Are the springs really ancient in reference to the earth's history, or, 

 like the course of the present rivers and the actual shape of our hills 

 and vallevs, are they only of high antiquity when contrasted with the 

 brief space of human annals ? May they not be like Vesuvius and 

 Etna, which, although they have been adding to their flanks, in the 

 course of the last 2^000 years, many a stream of lava and shower of 

 ashes, were still mountains very much the same as they now are in 

 hight and dimensions from the earliest times to which we can 

 trace back their existence ? Yet although their foundations are tens 

 of thousands of years old, they were laid at an era when the Medi- 

 terranean was already inhabited by the same species of marine shells 

 as those with which it is now peopled; so that these volcanoes must 

 be regarded as things of yesterdav in the geological calendar. 



fj C2 *' *J , 



Notwithstanding the general persistency in character of mineral 

 waters and hot springs ever since they were first known to us, we find 

 on inquiry that some few of them, even in historical times, have been 

 subject to great changes. These have happened during earthquakes 

 which have been violent enough to disturb the subterranean drainage 

 and alter the shape of the fissures up which the waters ascend. Thus 

 during the great earthquake at Lisbon in 17oo, the temperature of 

 the spring called La Source de la Heine at Bagneres de Luchon, in 

 the Pyrenees, was suddenly raised as much as 75 F., or changed from 

 a cold spring to one of 122 F., a heat which it has since retained. 



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