MISCELLANY. 



5S 



pounds each. This is just about one-half 

 the estimated weight of the largest of the 

 pyramids. To convey this amount by rail- 

 way carriages, of 8 tons each capacity, 

 would require 389,121 carriages, and, if of 

 20 feet length, they would make a train 

 1,4 7 3 miles long. 



When we consider that for each year 

 and upon each square mile of surface along 

 our ocean border, and many miles inland, so 

 vast a volume of water falls, we are aston- 

 ished at the grandeur and vastness of some 

 of the most common of the operations of 

 Nature. 



Prof. Agassiz's Sonth -American Obser- 

 vations* Prof. Agassiz and his scientific 

 party are continuing their explorations of 

 the South-American coast, in the steamer 

 Hassler, and the professor has just made a 

 second report to the Superintendent of the 

 Coast Survey on the progress of his obser- 

 vations. As is well known, Prof. Agassiz 

 undertook this expedition to accumulate 

 evidence in regard to the extent of glacial 

 action in producing geological effects. He 

 has been a student of glaciers for forty 

 years, grew up in a glacial region, and is 

 familiar with the phenomena ; early framed 

 a theory upon the subject, and feit so cer- 

 tain of the truth of his views, that he pre- 

 dicted with great confidence the results of 

 the explorations now undertaken. He says : 

 "As soon as geologists have learned to ap- 

 preciate the extent to which our globe has 

 been covered and fashioned by ice, they 

 may be less inclined to advocate changes of 

 level between land and sea, wherever they 

 meet with the evidence of the action of water, 

 especially where no marine remains of any 

 kind mark the presence of the sea." He 

 confirms many of Darwin's observations 

 made in the same region thirty years ago, 

 but thinks he ascribed too much to the 

 agency of upheavals. Nevertheless, he dis- 

 covered a salt-pool with marine animals, in 

 the interior, near Possession Bay, which were 

 undoubtedly due to upheaval. He says : 



About a mile from the shore bluff, I 

 found, nearly 150 feet above the sea-level, 

 a salt-pool, in which, to my great surprise, 

 marine shells, identical with those now liv- 

 ing along the shore, were abundant. They 

 were in a perfect state of preservation, and 

 many of them were alive ; so that I gath- 



ered a number of specimens with the living 

 animal, which I have preserved in alcohol. 

 The most common were ferns, myrtilus, buc- 

 cinum, fissurella, putella, voluta, etc., all 

 found in apparently the same numeric rela- 

 tion as that in which they now exist in the 

 sea below the clifi". The presence of this 

 pool, with its living inhabitants, shows a 

 very recent upheaval of the coast. The 

 period at which it may have taken place it 

 is hardly possible to determine without a 

 more extensive survey. 



But these and other evidences of up- 

 heaval do not disturb his profound convic- 

 tion that ice has been the grand agency by 

 which the southern continent has been 

 moulded, as appears from the following : 



It was not till we rounded Cape Fro- 

 ward that I felt confident that the range of 

 hills immediately in sight along the channel 

 we followed had assumed their present ap- 

 pearance in consequence of abrasion by ice. 

 Now, however, that I have seen the whole 

 length of the Straits of Magellan, have passed 

 through Smyth's Channel, and visited Chi- 

 loe, I am prepared to maintain that the 

 whole southern extremity of the American 

 Continent has been uniformly moulded by a 

 continuous sheet of ice. Everywhere we 

 saw the rounded, undulating forms so well 

 known to the students of glacial phenomena 

 as roches moutonnees, combined with the 

 polished surfaces scored by grooves and fur- 

 rows, running in one and the same direc- 

 tion ; while rocks of unequal hardness, dikes 

 traversing other rocks, slates on edges, 

 were all cut to one level. In short, the 

 surface features of the Straits of Magellan 

 have much the same aspect as the glaciated 

 surfaces of the Northern Hemisphere. 

 Whenever the furrows and scratches were 

 well preserved, their trend was northern. 



Notes on the Seychelles Islands. In 



August, 1871, Nicholas Pike, Esq., U. S. con- 

 sul at Mauritius, visited the Seychelles Isl- 

 ands, a group lying 900 miles northeast of 

 Mauritius, in the Indian Ocean. They are 29 

 in number, some of them mountainous, 

 comprising about 50,000 acres of land, and 

 lie between 3 33' and 5 45' south latitude. 

 Most of them are covered with tropical ve- 

 getation. 



The shores are fringed with coral-reefa 

 in all places favorable to their growth. 

 Gigantic astrseas, brain-corals, madrepores, 

 and coral shrubbery of many hues, cover the 

 'reefs of which they form a part. 



Consul Pike visited many of the islands 

 and made an interesting sketch of their nat- 



