GEOLOGY. 281 



next noticed the few patches of fossiliferous pleistocene deposits yet observed 

 on the Arctic shores, and the drift phenomena of the whole region under con- 

 sideration. 



ATTEMPTS TO SOUND THE NIAGARA RIVER. 



Several attempts have recently been made to sound the river below Niagara 

 Falls, one of which is thus described: " The attempt was made with an iron 

 of about 40 Ib. weight, attached to a No. 11 wire, all freely suspended, so as 

 not to impede the fall of the weight. I then let the weight fall from the 

 bridge, a height of 225 feet. It struck the surface fairly, with the point down 

 must have sunk to some depth, but was not longer out of sight than about 

 one second, when it made its appearance again on the surface, about 100 feet 

 down the stream, and skipped along like a chip, until it was checked by the 

 wire. We then commenced hauling in slowly, which made the iron bounce 

 like a ball, when a, cake of ice struck it, and ended the sport. I am satisfied 

 that no metal has sufficient specific gravity to pierce that current, even with 

 a momentum acquired by a fall of 225 feet. The velocity of the iron when 

 striking must have been equal to 124 feet per second ; and, consequently, its 

 mementum near 5,000 Ibs. Its surface opposed to the current was about 50 

 superficial inches. This will give an idea of the strength of that current, and 

 at the same time hint at the Titan forces that have been at work to scoop out 

 the bed of the Niagara river." 



OBSERVATIONS OX THE COAL-FIELDS OF PENNSYLVANIA. 



The following interesting remarks on the coal-fields of Pennsylvania are 

 made by Professor H. D. Rogers, as introductory to a description of numerous 

 species of new fossil plants found there : 



The following new species of fossil plants, one hundred and ten in number, 

 are some of the results of a systematic investigation of the fossil flora of the 

 carboniferous strata of Pennsylvania and the adjacent coal-fields of Ohio and 

 Virginia. Many of these hitherto undescribed forms were discovered in the 

 slates, associated with the beds of anthracite in the coal-fields of eastern Penn- 

 sylvania, which, compared with the bituminous coal measures of western 

 Pennsylvania, appear not only to contain a greater variety of species, but to 

 present them hi a condition of more perfect preservation for study. 



These species, as briefly described by Mr. Lesquereux, associated with Pro- 

 fessor Rogers in the Geological Survey of Pennsylvania, constitute about one 

 half of the total number of well-defined forms hitherto detected by him in the 

 coal measures and lower carboniferous rocks (the vespertine series) of Penn- 

 sylvania ; more than one hundred of the two hundred and twenty species ex- 

 amined by hi rr. proving to be entirely identical with species already recognized 

 in the European coal-fields, and some fifty more of them showing differences 

 so slight, that a fuller comparison with better specimens, may result in their 

 identification likewise. As a further evidence of the near affinity of the North 

 American to the European fossil flora of the carboniferous age, he has re- 



