22 



POPULAR OFFICIAL GUIDE. 



In three of the four principal valleys of the Park, bogs 

 have been converted into ponds, and in the largest and deep- 

 est of all lie Bronx Lake and Lake Agassiz. The bed-rock 

 underlying or cropping out in the Park exhibits pink gran- 

 ite, gray granite, rotten gneiss, and quartz in bewildering 

 variety. Occasionally in trench-digging a ledge is encoun- 

 tered which yields good building-stone for rough work, "but 

 usually our rock is so full of mica as to be worthless. 



The water-levels in the various portions of the Park are 

 as follows : 



Above Sea Level. 



Surface of Bronx Lake 20.40 feet 



Surface of Lake Agassiz 31.70 " 



Surface of Cope Lake and Duck Ponds. . 47.00 " 



Surface of Wild-Fowl Pond 65.00 ' ' 



Surface of Beaver Pond 44.00 " 



The floor levels of some of the important buildings are as 

 follows : 



Above Sea Level. 



Of the Antelope House 88 feet 



Of the Reptile House 78 " 



Of the Lion House 64 " 



Of the Aquatic-Bird House 57 " 



Soil. — The soil varies from rich black" muck in the valleys, 

 to light and very dry soil, full of mica and sand, on the 

 ridges and meadows. Where not packed hard, the latter is 

 very porous, and the heaviest rainfall is quickly absorbed, 

 or carried away on the surface. As a result, the valleys are 

 always moist and rich in grass, and the slopes and ridges 

 are always dry and warm. 



Streams and Ponds. — The Zoological Park contains about 

 34 acres of still water, of which Bronx Lake comprises 25 

 acres, Lake Agassiz b T /i acres, Cope Lake, the Wild-Fowl 

 Pond, and Beaver Pond together, about i l / 2 acres. The 

 two larger lakes are fed by the Bronx River, which drains 

 a valley about 15 miles long. Even in the driest seasons the 

 volume of water carried down by the Bronx River is suffi- 

 cient to keep the lakes well filled. The areas of still water 

 available for animal collections are very generous for an 

 institution like this, and are highly prized. 



The Waterfall. — At the lower end of Lake Agassiz, and 

 about 300 feet above the Boston Road Bridge, is a natural 

 waterfall nearly 12 feet in height, where the Bronx River 

 falls over a rugged ledge of pink granite. In times of high 



