286 ANNUAL OF SCIENTIFIC DISCOVERY. 



curious fact connected with the- inverted proportions, as regards the 

 number of meteoric falls of recent date, and of irons whose time of fall 

 is unknown, for the two continents. The European has, for a given 

 period of time, more than four times the number of the former, and 

 less than half that of the latter. What do we recognize here, but a 

 fresh proof of the erroneous use of the word new, if understood in a 

 geological sense, as applied to our portion of the earth ? The medals 

 we are now examining add their testimony to the abundant evidence 

 already possessed by the geologist, that, after all, we are the true den- 

 izens of the Old World. To the question which very naturally pre- 

 sents itself in this place, Do these zones upon the opposite sides of 

 the Atlantic connect by a watery region, subject to similar deposits 

 from the atmosphere ? we are wholly without evidence. 



If, then, it appears that these aerial strangers alight upon our earth 

 in such great preponderance over limited areas, can \ve help admitting 

 that there presides over their descent some great law, or, in other 

 words, that these falls take place in accordance with some fixed plan. 

 The present stage of our knowledge may, indeed, ba inadequate to 

 develop what that plan actually is,; but when we see so marked an 

 approach by the courses of our meteoric regions to the isothermal par- 

 allels for the same zones, and, again, an observable coincidence be- 

 tween the trends of the meteoric regions and the isodynamic lines, 

 we are strongly tempted to refer the forces of greatest activity con- 

 cerned in the phenomenon to a union of thermal and magnetic ac- 

 tion, although it is at the same time possible, that more powerful lo- 

 cal attractions in the surfaces concerned, than exist elsewhere, may 

 also exert some influences over the deposition of these singular bodies. 

 Prof. C. U. Shcpard to the American Association, at Charleston. 



NEW AMERICAN METEORITES. 



SEVERAL new American meteorites have within the past year been 

 noticed and described by Prof. C. U. Shepard. The first fell during 

 a severe thunderstorm, in the summer of 184G, about 20 miles east of 

 Columbia, S. C. A negro saw it fall, and carried it to his mistress, 

 saying that he had found " a lump of solid thunder." It differs from 

 all other meteoric stones yet observed, in figure as well as in composi- 

 tion. It is nearly round and almost perfectly smooth, having only 

 very slight elevations and depressions over its surface. Its diameter 

 is about 2 inches, and its weight Gi ounces. 



Its composition is as follows : 



Silica 80.420 



Alumina ...... 15.680 



Protoxide of Iron .... 2,513 



Magnesia ...... 0.700 



Lime 0.500 



99.813 



Sp. Gr. = 2.32. From this analysis, says Prof. S., it is apparent 

 that this stone, though coming within my trachytic order, stands at a 



