Every twenty-four hours or so the flow of juice may be conveniently stopped, and, after all the impurities have subsided, the superincumbent clear liquor may be decanted by a cock placed at the side of the cone for the purpose, and the vessel may be washed out.
But in life--as we have elsewhere seen--this inclined plane is angularly filled up, and almost squared by the enormous superincumbent mass of the junk and sperm.
A liquid boils when its vapour pressure equals the superincumbent pressure (see Vaporization); consequently any process which diminishes the external pressure must also lower the boiling-point.
The laminated structure of shales, though partly due to successive very thin sheets of deposit, is certainly dependent also on the vertical pressure exerted by masses of superincumbent rock; it indicates a transition to the fissile character of clay slates.
The material of the bank being loosened by blasting and the cutting action of the water, crumbles into holes, and the superincumbent mass, often with large trees and stones, falls into the lower ground.
For the remaining distance the brine is raised by a pump. The fresh water, however, as it descends rises to the surface of the salt, tending rather to dissolve its upper layers and extend superficially, so that after a time the superincumbent soil, being without support, falls in.
Van Bemmelen has shown that the red hydrates are really colloids, the amount of water retained being such that its vapour pressure equals the pressure of the aqueous vapour in the superincumbent atmosphere.
In 1866 primitive structures were discovered in the island of Therasia by quarrymen extracting pozzolana for the Suez Canal works; and when this discovery was followed up in 1870, on the neighbouring Santorin (Thera), by representatives of the French School at Athens, much pottery of a class now known immedi ately to precede the typical late Aegean ware, and many stone and metal objects, were found and dated by the geologist Fouque, somewhat arbitrarily, to 2000 B.C., by consideration of the superincumbent eruptive stratum.
The second conclusion is that, as a general rule, the incandescent heavenly bodies are not masses of solid or liquid matter as formerly assumed, but mainly masses either of gas, or of substances gaseous in their nature, so compressed by the gravitation of their superincumbent parts toward a common centre that their properties combine those of the three forms of matter known to us.