But M. Dufour suggests that the retardation of the earth (which is hypothetically assumed to exist) may be due in part, or wholly, to the increase of the moment of inertia of the earth by meteors falling upon its surface.

The use of submarine or of subterranean conductors occasions, from the above cause, a small retardation in the velocity of the transmitted electricity.

It is the writer's art so to arrange words that they shall suffer the least possible retardation from the inevitable friction of the reader's mind.

The voyage lasted a month, tedious and monotonous, more trying than his retardation on land, for there at least he could recover some serenity by violent exercise.

The slightest possible retardation at its close brought us to the refrain of the simple adagio, interrupted again by a rush of violoncello-notes, rapid and low, like some sudden under-current striving to burst through the frozen sweetness.

The fact appears to be that the amount of the resistance denominated friction depends, in a great measure, upon the nature of the unguent employed, and in certain cases the viscidity of the unguent may occasion a greater retardation than the resistance caused by the attrition.

Cornu, in answering the objection that there may be an unknown retardation by reflection from the distant mirror, says that if such existed the error it would introduce in his own work would be only 1/7000 that of Foucault, on account of the great distance used, and on account of there being in his own experiments but one reflection instead of twelve.

Messrs. Adams, Thomson, and Tait work out this suggestion, and, "on a certain assumption as to the proportion of retardations due to the sun and moon," find the earth may lose twenty-two seconds of time in a century from this cause.