NEW CONE AND OBELISK OE MONT PELE 559 



stroyed Saint Pierre, the new cone, as observed from the sea, seemed to be 500 

 or 600 feet in height. By the end of May the top of the cone was about on a level 

 with the eastern rim of the great crater, indicating a growth of about 1,600 feet. 

 In the latter part of June the height was about the same. At these times great 

 masses of rock were observed projecting from the sides of the new cone, and early 

 in July a mass like a shark's fin projected above its top. In August observers 

 noted a spine surmounting the new cone, which by this time rose many yards 

 above the old summit plateau of the mountain. In October Professor Lacroix got 

 observations which led him to the conviction that the main body of the cone with 

 its obelisk had been pushed up bodily from below in a solid or practically solid 

 condition. 



From October, 1902, began the growth of the wonderful spine which is the most 

 striking feature of the eruption of any volcano within human history. The re- 

 markable average of 41 feet per day was the record of upward growth for this por- 

 tion of the mountain in eighteen days of November, 1902. On the 26th of that 

 month the apex of the spine was 5,032 feet above the sea, or 600 feet higher than 

 the old culminating point of the mountain, and 2,700 feet higher than the level of 

 PEtang Sec, the starting point of the new cone. In the succeeding five weeks 

 about 340 feet of this altitude was lost, but in March, 1903, the spine began to rise 

 again and finally attained an altitude of 5,300 feet above the sea near the end of May. 



The usual activity of the volcano seems to have pushed this cone and spine 

 upward, while the eruptions which took place from time to time tended toward the 

 destruction of the spine and the disintegration of the cone. During April some of 

 the spine was destroyed. In May the loss was recovered, but on the 30th of May 

 165 feet were lost from the top. During June much of the old altitude was regained, 

 but between the 5th and 6th of August more than three-fourths of that part of the 

 spine projecting above the cone disappeared, and inont Pele's wonderful spine 

 ceased to be a feature of the mountain. The loss of the spine, however, was made 

 good in part by the elevation of the " dome " or main portion of the cone, which by 

 the middle of October was about 400 feet higher than it had been before the loss of 

 the spine. Since then the continued explosions in the mass have carried away the 

 western portion of the top of the cone, leaving a sharp, almost overhanging, fin- 

 like ridge along the eastern side of the cone. The outline, however, is changing 

 constantly, and alternating elevation and loss of height continue. 



The axis of the cone is not central within the old crater, but rises in the north- 

 west quarter. There was a spiral valley between the new cone and the old crater, 

 which gradually diminished in depth, and disappeared on the western and north- 

 western sides, where, by March, 1903, the slope of the inner cone became continu- 

 ous with that of the old outer cone. In June, 1902, the author estimated this 

 valley to be 800 feet deep, beside the remains of Morne Lacroix, on the eastern side 

 of the crater. In March, 1903, the valley at the same place could not have been 

 more than 200 feet deep, and the activity since that time is reported to have re- 

 duced even this depth. Judging from the debris found in the valley of the Riviere 

 Blanche and on the rim of the crater, the material of this new cone and spine is 

 andesite, which is partly lithoidal, partly densely vitreous, and partly pumiceous 

 in texture. The formation of true pumice during the present series of eruptions 

 seems to be definitely indicated by the freshness of the material of this character 

 which is to be found scattered in loose blocks in many parts of the mountain. 



A less striking but still interesting feature of the eruptions has been the filling of 



