338 



KEPORT UNITED STATES GEOLOGICAL SURVEY. 



AFRICAN THERMAL SPRINGS. 



The African continent, so far as known, is of all the continents most 

 free from volcanic action, and we do not, therefore, expect to find hot or 

 warm springs at all prominent, except in connection with its mount- 

 ains.* There are only ten volcanoes in Africa, and earthquake shocks 

 appear to be comparatively unknown. This dark continent, however, 

 is having light shed upon it, and its future geological exploration will 

 doubtless reveal the presence of many thermal springs. Still they will 

 probably never equal those of other portions of the world, although we 

 shall expect them to occur in or near areas of volcanic rocks, or near 

 mountain ranges where there are faults and dislocations. 



SPRINGS OF HAMMAM MESKHOrTIN^E. 



These springs are in the province of Constantine, in Algeria, having 

 a temperature of 203° F., and are remarkable for their deposit, which is 

 calcareous. Most of it is wliite striped with bright colors. Some of it 

 is in masses, like walls, one of which is 6C feet high, 4,921 feet long, and 

 from 33 to 49 feet wide. In other places there are numerous crater-like 

 cones. 



The thermal springs of the northern part of Africa maybe considered 

 as on the volcanic line of the Mediterranean, referred to in the previous 

 chapter. The Azores also lie on what may be considered the western 

 extension of this line. Many of the springs given in the catalogue were 

 celebrated in ancient times, and are marked now by ruins of baths erected 

 in the past. 



In Southern Africa the thermal springs are probably due in part at 

 least to the presence of mountains. The diiferent springs have consid- 

 erable reputation for therapeutical use. 



Madagascar has numerous thermal springs, but they are avoided by 

 the natives, probably on account of superstitious fears for which reason 

 Indians avoid the Yellowstone National Park. The two islands, St. Paul 

 and Amsterdam, are volcanic craters. The former is generally described 

 as having hot springs, although some mention only the latter. On St. 

 Paul the springs are on the north side of the basin. One is called the 

 Bath and the other the Drinking Fountain. The water is boiling hot 

 except at high water, when the sea pours into the crater and lowers tke 

 temperature. 



TaMe of the thermal springs of the Azores, Africa, and the islands of the Indian Ocean. 

 [For authorities see BibliograpMcal Appendix G.] 



Locality. 



Country. 



Highest tem- 

 perature. 



!Fnmas Valley, island of San Miguel . 



Near Santa Cruz, island of Flores 



<jfbasa, in Morocco 



Toeer, in Morocco 



Dra el Hammah, in Morocco 



Gran, in Algeria 



Hammam Rira, in Algeria 



Hammam el Euf, in Algeria 



Haniman Verda, in Algeria 



Azores. 



do 



Africa . 



do 



do 



do 



do 



do 



do 



°F. 



Hot. 



212 

 95? 



Hot. 

 Hot. 



167 



* There are four volcanoes on the west coast and six on the east. The Camaroon 

 Mountains, on the coast of Guinea, are volcanic. Artali, between the Red Sea and the 

 Abyssinian plateau, is a volcano. Hot springs are prevalent in Abyssinia along the 

 coast in connection with the voicanic formations, and are also abundant in the Dana- 

 kel country. 



