446 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
The midlaad parts of the island are of course the highest. Through the county 
of Surrey, and partly through Middlesex, there runs the great central chain, which 
trends generally in an east and west direction, the highest part of which is the Blue 
Mountain Peak, attainin g an elevation of 7,360 feet. 
From this range subordinate ridges or spurs run northerly to the north side of the 
island, and southerly to the south side; these ridges in their turn are the parents of 
other smaller ridges, which branch off iu every direction with considerable regularity 
and method ; and they again throw off other ridges, until the whole surface of the 
country is cut up into a series of ridges with intervening springs or gullys. 
RIVERS OF JAMAICA. 
While most of the rivers have generally northerly and southerly directions, it must 
not be forgotten that the subordinate ridges, which are nearly at right angles to these 
lines, will produce subordinate streams, meeting the rivers on their eastern and west- 
ern banks. 
In consequence of the great elevations from which most of the rivers flow they are 
very rapid in their descent, and in times of flood become formidable torrents, sweeping 
everything before them and operating as dangerous obstructions to the traveler. 
Bio Grande River, in the parish of Portland, is one of the finest rivers in the island; 
it flows from the northern slopes of the Blue Mountains. The Back and Stony Bivers, 
two of its great affluents, furnish not only some of the loftiest and most picturesque 
water-falls, but the wildest and most romantic country in the island. 
The elevation of the western peak of the Blue Mountains is 7,360 feet. 
The mean annual temperature of the air at 7,500 feet is 57.4°. 
The upper districts of this region are too cold for coffee, but suitable for cinchona. 
Lower portions are adapted to coffee and cocoa. 
Swift River, in the parish of Portland. It has the same character as the Rio 
Grande. 
Spanish River, in the parish of Portland. It has the same character as the Rio 
Grande. 
Buff Bay River, in the parish of Portland. It has the same character as the Rio 
Grande. 
AguaAlta ( Wag Water) River, in the parish of St. Andrew. It rises in the mount- 
ains back of Stony Hill ; runs through the parishes of St. Andrew and St. Mary, 
debouching at Aunott Bay. 
The elevation of Stony Hill, where main road crosses it, is 1,360 feet. 
The air temperature of Stony Hill, at an elevation of 1,425 feet, is 75°. 
YallaWs River, in the parish of St. Thomas. In consequence of the great eleva- 
tion from which it flows it is very rapid in its descent, and in times of flood becomes 
a formidable torrent. 
Yallah’s Hill is 2,348 feet high. 
The mean annual temperature at this elevation is about 72.6°. 
The Hope River rises in the hills around New Castle, and joins the sea at the sixth 
mile-stone from Kingston, on the windward road. From this river the city of Kings, 
ton is supplied with water. * 
