In the sphere of living environment, the varied evolution of plant life, the periods of forestation and deforestation, the introduction of deleterious plants simultaneously with harsh conditions of life and enforced migration, as well as of mechanically dangerous plants, are among the well-ascertained causes of diminution and extinction.
It is true we find many thinkers who' deny the competency of reason when it ventures in any way beyond the sphere of experience, and such men are not unfrequently called sceptics.
The Keplerian like the Pythagorean cosmos was threefold, consisting of the centre, or sun, the surface, represented by the sphere of the fixed stars, and the intermediate space, filled with ethereal matter.
Bonaparte signalized his tenure of power by no very important developments in the sphere of elementary education.
When the source S is inside the sphere and H outside, the line sink must extend from H to infinity in the image system; to realize physically the condition of zero flow across the sphere, an equal sink must be introduced at some other internal point S'.
But after the Armistice the unsatisfactory consequences of the peace negotiations, the heavy burden of suffering and loss caused by the war, and, above all, the intolerable internal policy of the Nitti Cabinet, which seemed prepared to hand the country over to the Bolshevist Socialists, brought about the return of Giolitti to the sphere of practical politics once more.
The vernal equinox is taken as the initial point on the sphere from which co-ordinates are measured in the equatorial and ecliptic systems. Referring to fig.
Asiatic Russia, especially eastern Siberia and Mongolia, have been brought within the sphere of Russian exploration, with results so surprising as to form an epoch in the history of Asia.
In the course of the next six months there was much desultory skirmishing between the tribes and the British troops, who defeated various attempts to dislodge them from the positions that had been taken up; but the sphere of British military operations was not materially extended.
The secular importance of Henry's activity has been somewhat obscured by his achievements in the sphere of ecclesiastical politics; but no small part of his energies was devoted to the task of expanding the royal authority at the expense of temporal competitors.