Address Delivered before the Section of Algebra and Analysis of the International Congress of Arts

relieved, as by sinking a vacant shaft down to it, a violent explosion would follow. The author concluded from Laplace's law of density that the planet Venus has a rigidity equal to that of a corresponding globe of glass, and that the nuclei of all large bodies are effectively of the highest rigidity. The development of pressure as we decend in the globe was shown to be such as to invalidate the conclusions of Lord Kelvin and Professor G. H. Darwin respecting the consolidation of earth by the building up of a solid nucleus from the sinking of the solidified crust.