244 ANNUAL OF SCIENTIFIC DISCOVERY. 



by Le Pere, may be accounted for by the fact of the work being exe- 

 cuted under the orders of Napoleon, during the campaign in Egypt, a 

 period of war of the most harassing description. The ridge now existing 

 at the end of the Red Sea, towards the Bitter Lakes, is found to con- 

 sist of tertiary strata, the fossils of which are identical with those of 

 the London Basin, and the hill of Montmartre, Paris ; and has no 

 doubt resulted from a geological upheaval which materially changed 

 the features of the district. 



RECOGNITION OF A MATHEMATICAL LAW IN GEOLOGICAL SCIENCE. 



M. DE BEAUMONT, in a communication to the French Institute, an- 

 nounces a discovery which may probably lead to important results in 

 geological investigations. It is a well-known law in geometry, that if a 

 number of cylindrical bodies be compressed parallel with their axis, by 

 forces acting at right angles thereto, they assume the form of hexagonal 

 prisms, the simple cause of which law is, that a plane can only be 

 exactly divided, without loss of space, by three regular figures the 

 equilateral triangle, the square, and the hexagon of which figures the 

 hexagon has the least perimeter, which form the bee, from natural 

 instinct, adopts for its honey cells ; and, by the same law, the basalts 

 in general assume the shape of six-sided prisms. If a spherical body 

 be submitted to equal pressure in all directions, a similar law is called 

 into action, but with different results, a sphere being only capable of 

 division into a series of dentagonized triangles. The fifteen great cir- 

 cles which divide a sphere into as many regular pentagons, possess the 

 minimum of lineal extent, which constitute the most complete equa- 

 tion of lines. In availing himself of this law, M. de Beaumont attempts 

 the explanation of an ingenious theory of the regularity of the angles 

 of the great mountain chains upon the globe. It was known that the 

 principal direction of these systems follows that of the great circles of 

 the earth ; and the author, in studying the direction of twenty-one 

 mountain chains of Europe, has found that the angles formed by these 

 circles towards each other, have an almost constant value, and the 

 chains are assembled in groups, forming nearly right angles. Com- 

 paring those angles with the simple pentagonal net which envelops 

 the sphere, and dividing it into 120 scalene triangles of equal magni- 

 tude, he found the angles by which the fifteen great circles are inter- 

 sected to be 36, 60, 72, and 90. These facts, in connection with 

 other geographical phenomena, have led M. Beaumont to consider these 

 formations as the result of the folds, or plications, caused by the suc- 

 cessive contraction of the mass of the globe in the process of refrigera- 

 tion. London Mining Journal. 



ON THE PLICATION OF STRATA. 



AT a meeting of the Boston Natural History Society, March, 1850, 

 Prof. H. D. Rogers called the attention of the members to the following 

 question in geology, viz. : Why are curves in the earth's strata not 

 symmetrical, but always more abrupt on one side than the other, as 



