182 Reviews — Belfs Naturalist in Nicaragua. 



5000 feet, clofhed to the summit with perennial verdure ; the volcano 

 of Masaya, active at the time of the Spanish Conquest in 1522 ; close 

 to this cone is situated the lake of Masaya, which is of large extent, 

 and may perhaps at one time have been an old crater-lake, like that 

 of Kilauea, in Hawaii. The walls of this lake are precipitous cliffs, 

 348 feet high, composed of massive trachyte, overlain by beds of 

 ashes, breccia, and cinders ; these are covered by a deposit of fine 

 tufa, with imbedded angular masses of trachyte, some of which are 

 more than three feet in diameter. The uppermost layer is composed 

 of lightly-coherent tufaceous ash, worn into an undulating surface by 

 meteoric agents. 



In 1866 Mr. Belt published a paper in the Transactions of the 

 Nova Scotian Institute of Natural Science (p. 93), on "the Glacial 

 Period in North America " ; it is not therefore surprising to find 

 the author carrying on his observations of glacial phenomena 

 in Central America. Nearly everywhere the author sees evidences 

 of ice-action in the accumulations of gravel with boulders of gneiss, 

 quartz, trap-rock, and conglomerate. " The evidences of glacial 

 action between Depilto and Ocotal, " writes Mr. Belt (p. 260), 

 "were, with one exception, as clear as in any Welsh or Highland 

 valley. There were the same rounded and smoothed masses of 

 rock, the same moraine-like accumulations of unstratified sand and 

 gravel, the same transpoi'ted boulders that could be traced to their 

 parent-rock several miles distant. The single e'xception was, I saw 

 no glacial scratches on the rocks." 



Without venturing for one moment to call in question Mr. Belt's 

 accuracy as an observer, we cannot help thinking it possible that the 

 effects of torrential action, and the accumulations of old sea-coasts, 

 may, after elevation of the land and re-arrangement by river- 

 action and other causes, be mistaken for glacial moraine matter ; at 

 any rate, so good an observer as the late Professor Agassiz certainly 

 mistook alluvial matter for moraine matter in the Amazons valley.^ 



Again, at p. 262, the author says, " I could no longer withstand 

 the evidence that had been gradually accumulating of the presence 

 of large glaciers in Central America during the Glacial Period, and 

 these once admitted aiforded me a solution of many phenomena 

 that had before been inexplicable. The immense ridges of Boulder- 

 clay between San Eafael and Tales, the long hog-backed hills near 

 Tablason, the great transported boulders two leagues beyond 



Libertad, could all be easily explained on the supposition 



that the ice of the Glacial Period was not confined to extra-tropical 

 lands, but in Central America covered all the higher ranges and 

 descended in great glaciers to at least as low as the line of country 

 now standing at 2000 feet above the sea, and probably much lower." 



Mr. Belt thinks geologists will be forced to the conclusion that 

 " the Glacial Period was not only more extensive than has been 

 generally supposed, but that it existed at the same time in the 

 northern and southern hemispheres, leaving, at least on the American 



' See letter from Mr. C. F. Hartt, Silliman's American Journal, No. 19, for July, 

 1872, p. 63. See also Geol. Mag. 1873, Vol. X. p. 540. 



