Peoceedings of the Polytechnic Association. 925 



several clouds, cloudlets, or globules, as mentioned before, and that 

 several individualities charged with like electricity, repel each other ; 

 but no one can be so repelled as to impinge, unduly, on those beyond 

 it ; all are maintained in equilibrio in the mass, which, by their 

 agglomeration, they help to compose. 



Now it must happen that all the individualities of every grade 

 become, as it were, polarized for the reason that, above them all, is 

 an atmosphere highly positive, and below them the earth which is 

 negative. The positive atmosphere induces negative electricity in 

 the upper portion of the upper stratum, driving the positive into the 

 lower portion by which its normal tension is largely increased ; this 

 acts in the same manner upon the next stratum below. The negative 

 earth, too, is acting to produce the same effect upward. It induces 

 positive tension in the lower portion of the lower stratum, and that 

 in the lower portion of the next, and so on, 



Wnder sucli a system of actions and reactions among the several 

 individualities between the negative earth, and the upper positive 

 atmosphere, the surface of the earth must become endowed with a 

 negative tension very far beyond that which is natural or common, 

 and the lower portion of the lower stratum must also acquire a posi- 

 tive tension far beyond what it could possibly attain, if it were not so 

 largely reinforced by the strata above. 



They all act, like so many spans of horses, one before another, 

 drawing in the same direction. The amount of lifting force then, 

 exerted by such a stupendous magnetic battery, which in some cases 

 may act, nay, does act, upon a single square mile of earth, it is scarcely 

 within the scope of the imagination to conceive ; it can be estimated 

 only by millions of tons. 



All loose substances, as well as trees, buildings, &c., are rendered 

 powerfully negative, and are, therefore, repelled by the negative 

 earth, while they are powerfully attracted by the superincumbent 

 cumuli. N"ow we can see the rationale of those remarkable phenom- 

 ena, the r-az de maree, in which the sea is raised to the height of three 

 or four, and even to six or seven feet. They consist in the changes 

 of level that are suddenly manifested without there being anything 

 that can cause them to be anticipated. 



Burtrand was the first to conceive and to explain that it was by the 

 attraction of electric clouds that the waters were thus raised. We 

 can now see why it is, that sometimes when a heavy cloud is hanging 

 over us, tlie leaves, dust and other light substances when agitated by 



