570 PROCEEDINGS OF THE PHILADELPHIA MEETING 



gles with the sulphur. Kaolin results from the decomposition of the feldspars of 

 the original rocks. 



The sulphur springs area lies on the northeast flank of the Soufriere mountain, 

 and seems not to be the remains of or connected in any way with an ancient 

 crater. It is not always easy, or perhaps even probable, to determine the exact 

 position of beds which are so deeply decomposed and so heavily covered with vege- 

 tation as these of Saint Lucia, but the convex character of the ridge on which the 

 sulphur springs area is located and the general relations of the mountains to one 

 another seem to preclude the idea of the existence of a crater at this point. Some 

 effort has been made to mine the sulphur deposited here, but the enterprise has 

 not been a commercial success. 



The paper was illustrated with lantern slides. 



BOILING LAKE OF DOMINICA * 

 BY EDMUND OTIS HOVEY 



[Abstract] 



The island of Dominica is entirely volcanic in origin, but high-level marine 

 beaches and benches, coral beds, and river terraces indicate comparatively recent 

 elevation amounting to not less than 500 feet. Dominica is one of the largest and 

 highest of the Lesser Antilles. The altitude of the land mass produces copious pre- 

 cipitation, and the surface consequently is well dissected. The rivers for the most 

 part are still deepening their V-shaped channels, and only the larger streams, like 

 the Eoseau, the Layou, and some others, have flood-plains. Marine erosion has 

 advanced more rapidly than stream erosion and bluffs form the major portion of 

 the coast. 



Many warm and hot springs and fumaroles occur in different parts of the island, 

 and residents report the existence of volcanic craters in Morne Diablotin, the cul- 

 minating point of the island (4,747 feet), and elsewhere in the mountains. The 

 best known and most important center of volcanic activity is the Grande Soufriere, 

 about 6 miles east-northeast of the town of Roseau. Here is situated the famous 

 Boiling lake of Dominica. The Grande Soufriere was in feeble eruption for a brief 

 period in 1880, ashes being thrown as far as Roseau. 



The whole fumarole area of the Grande Soufriere is nearly a mile in longest 

 diameter, from southwest to northeast, and occupies a vast amphitheatrical depres- 

 sion in the northeast flank of Watt mountain. The amphitheater is breached to 

 the base toward the southeast, and resembles in form the present craters of Mont- 

 serrat and Nevis and that of Mont Pele before the eruptions of 1902 began. Within 

 the great crater-like depression there are many hot springs and steam vents, most 

 of which arrange themselves into four groups. The principal of these springs or 

 groups is the Boiling lake, lying in the extreme northeastern portion of the great 

 amphitheater. 



The Boiling lake is a circular pool of boiling water 50 or 60 yards across, in the 

 bottom of a pot-like basin, which may be 100 yards in diameter at top. The sur- 

 face of the lake is about 560 meters (1,837 feet) above the sea by uncorrected 

 aneroid measurement. Two beaches, about 2 and 5 feet above the water at the 



* Based upon field observations made for the American Museum of National History. 



