F. GEOGRAPHY. 147 



usually composed of numberless varieties within a limited 

 area. 



Below the falls of the Tapajoz Mr. Hartt discovered car- 

 boniferous rock, and made a collection of a large number of 

 species of marine fossils from this formation. The most in- 

 teresting physical feature of the Valley of the Amazon is the 

 elevated range of Erere, where the professor and his party 

 spent nearly a month making detailed surveys. The sierra 

 is composed of ancient rocks quite highly inclined, much dis- 

 turbed, while the plains at the northern base consist of hori- 

 zontal strata containing lower palaeozoic fossils, trilobites, etc. 

 The cliffs of Erere are covered with Indian paintings, nearly 

 all of which were carefully copied or photographed, and pre- 

 sented many interesting analogies to the inscriptions on the 

 Indian pottery found at Marajo, near the mouth of the river. 

 A special study of the Tupi language enabled Mr. Hartt to 

 collect many interesting facts regarding the primitive deni- 

 zens of the Amazon, their customs, habits, and peculiar meth- 

 od of teaching by symbolic fable. 



In making a geological section of some fifty miles of the 

 country near Santarem, they found a thick bed of recent Am- 

 azonian shells at a height of some fifty feet above the high- 

 est present level of the river, showing that in comparatively 

 recent times the waters covered a much greater surface at a 

 higher level. 



CRUISE OF SCHOOL-SHIP MERCURY. 



The Department of Public Charities and Correction in 

 New York has just published a report of the cruise of the 

 school-ship Mercury in the tropical Atlantic, in 1870-71, un- 

 der the command of Captain Giraud. This vessel, like the 

 Massachusetts school-ship, is intended to give practical train- 

 ing in seamanship to a class of vagabond boys, of whom no 

 other disposition could be made ; and as this was the first 

 experiment in New York, the result was looked for with a 

 great deal of interest. This was entirely satisfactory, as, out 

 of a crew of 258 boys, over 100 were, in the opinion of the 

 captain, capable, on the return of the ship, of discharging the 

 duties of ordinary seamen. The vessel in question sailed from 

 Hart's Island on the 20th of December, 1870, and after stop- 

 ping at the Madeira and Canary Islands, arrived at Sierra 



