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Page:Popular Science Monthly Volume 61.djvu/193

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THE PROGRESS OF SCIENCE.


PSM V61 D193 Global map of volcanic disturbances.png
Map of Volcanic Disturbances. (From Bonney's 'Volcanoes' Putnam's Science Series.)
|||| Signifies Extinct Volcanoes.
Signifies Active Volcanoes but is not intended to indicate either the number or the exact position.
- - - - - - Signifies the probable direction of lines of weakness in the earth's crust.