328 EEPORT UNITED STATES GEOLOGICAL SUEVEY. 



a Tiot spring whicli deposits silica, wMch is soft at first (gelatinous 

 silica), and afterwards becomes opaline. In the same region, also, near 

 Jaripeo and Taximaroa, there are boiling springs and mud holes.* The 

 mud volcanoes and springs of Central America are exactly similar to 

 those of the western part of the United States, already described. Those 

 at San Jazinto, in Nicaragua are said by Froebel to be at the boiling 

 point, and of various colors, viz : red, brown, yellow, blue, black, and 

 white.t 



WEST INDIES. 



There are six active volcanoes in the West Indies,| the great center 

 of activity being in the western line of theOaribbee Islands (Windward 

 Islands), which are the continuation, northward, of a branch of the vol- 

 canic line of South America. The thermal springs of Venezuela are on 

 this line, and make a connecting link between those of Caribbee Islands 

 and those of the main chain of the Andes. 



The larger islands of the West Indies, lying more to the westward, 

 are not igneous, but they are subject to earthquakes, especially Jamaica 

 and St. Domingo. In the latter island the earthquake of 1770 caused 

 hot springs to break out where no water previously existed, but they 

 afterwards ceased to flow. 



The temperatures of the springs in Jamaica and Cuba are comjjara- 

 tively low, and high temperatures are not noted until the Caribbees are 

 reached. Almost every one of the Windward Islands has its soufriere 

 or sulphur, connected with which are hot springs. St. Lucia and Domin- 

 ica are especially noted for their hot springs. The soufriere of St. 

 Vincent contains a lake, the color of which is described as being an 

 opalescent green. 



SOUFKlfeRE OF ST. LUCIA. 



The soufriere or sulphur of St. Lucia is in the crater of a volcano, 

 1,000 feet above sea level, and occupies an area of about three acres, in 

 which space there are at least fourteen caldrons in a state of constant 

 ebullition, boiling to the height of 3 or 4 feet, the steam having a sul- 

 phurous odor. In some of the caldrons the water is clear, in others it is 

 black. Fresh springs and fountains are continually breaking out. 

 This place was once celebrated for medicinal purposes, and baths were 

 constructed.§ 



BOILING LAKE IN THE GRAND SODFRlilRE OF DOMINICA. 



The boiling lake of Dominica was known as far back as 1777. It is 

 a seething caldron, measuring 200 by more than 100 yards, with per- 

 pendicular walls 60 to 100 feet in height. At a distance of 10 feet from 

 the edge there is no bottom at a depth of 195 feet. It is 2,400 feet above 

 sea-level, and is in active ebullition, especially in the center, where it is 

 geyser-like, the water being thrown in jets into the air, shifting from 

 side to side with a noise like the discharge of artillery. The temijera- 

 ture at the edge, according to Palgrave W. Gifford, is 185° F., and 

 farther in is 200^" F., || and in the center is doubtless at or even above 

 the boiling point, which here is about 207° F. 



* Sanssnre's Excursion to an Ancient Volcano in Mexico, Jour. Geog. Soc. of London, 

 Vol. XXX, 1860, pp. 53-58. 



t Seven Years Travel in Central America, &c., by Julius Froebel, London, 1859. 



X Judd, ib. cit. 



§ St. Lucia, by Henry Breen, London, 1844, pp. 7, 8. 



II West Indian Memories, by Palgrave VV. Gifford, MacMiUan's Mag., Vol. XXXV, 

 No. 209, March, pp. 361-374. 



