284 ANNUAL OF SCIENTIFIC DISCOVERY. 



The mountain ranges he considers to be nothing more nor less than 

 the material which in the original expanded globes formed the com- 

 paratively level crust of the moon and earth. The fall of the unsup- 

 ported crust on the retreating nucleus was described as yielding a very 

 probable explanation of the appearance of granitic and igneous centres 

 of certain mountain ranges, as well as the injection of igneous rocks 

 in the form of trap-dikes and basaltic formations, which appear to 

 have come forth in this manner from below the crust of the earth. 

 The origin of the bright lines radiating from certain volcanic centres 

 on the moon's surface was alluded to, and illustrated by the experiment 

 of causing the surface of a glass globe filled with water to collapse on 

 the fluid interior by rapidly contracting the surface while the water 

 had no means of escape. The result was the splitting or cracking up 

 of the surface in a multitude of radiating cracks, very much resembling 

 those on the moon. This subject was further illustrated by reference 

 to the manner in which the surface of a frozen pond may be made to 

 crack from pressure underneath, yielding radiating cracks from the 

 centre of convergence, vvhere the chief discharge of water will take 

 place, while simultaneously all along the lines of radiating cracks the 

 water will make its appearance, thus explaining how it is that the 

 molten material came forth from the moon simultaneously through the 

 course of cracks, and appeared on the surface as basaltic overflow, ir- 

 respective of surface inequalities. 



FALLING OF METEORITES OVER A LIMITED ZONE, OR AREA OF 



THE EARTH'S SURFACE. 



FROM the numerous discoveries of these bodies in the States of 

 North and South Carolina and Tennessee, within the last few years, 

 and from the many accounts of meteoric explosions (as yet unattended 

 by the finding of precipitated matter) over the same region, it occurred 

 to me that there might be a concentration in the deposition of such 

 bodies, not only on this continent, but possibly elsewhere. This 

 idea led me to jot down upon a map of the world the authentic falls 

 of meteorites, which have occurred since the commencement of this 

 century, as the best mode of bringing the conjecture to a test. The 

 result of this investigation seems to establish the existence of such a 

 zone or region, over which meteoric falls are more frequent than else- 

 where. The facts collated are these. Out of fourteen depositions of 

 meteoric matter on the American continent during the period above 

 referred to, thirteen, or 92.8 per cent., have taken place between the 

 parallels of 33 and 44 N. lat., while the remaining, or one fourteenth, 

 occurred at Macao, in the province of the Rio Grande del Norte, in 

 Brazil. Here, then, is presented a distribution at once exceedingly 

 unequal. Their deposition forms an imperfect stream, whose ex- 

 treme length is 11 of latitude, and in longitude is about 25. The 

 line of most frequent deposit cuts obliquely across the 37th parallel of 

 latitude, and manifests a partial tendency of conformation to the line 

 of the Atlantic coast. 



To show that this area has actually been the scene of most frequent 



