The screw consists of an axis of hollow brass tube, eighteen inches in length, through which, upon a semi-spiral inclined at fifteen degrees, pass a series of steel wire radii, two feet long, and thus projecting a foot on either side.
In the same way, the angle formed by the rope with the vertical axis of the machine, indicates the velocity.
This center, formed of indefinite molecules, began to revolve around its own axis during its gradual condensation; then, following the immutable laws of mechanics, in proportion as its bulk diminished by condensation, its rotary motion became accelerated, and these two effects continuing, the result was the formation of one principal star, the center of the nebulous mass.
The stony axis which gives strength to the stem may be traced at this extremity into a mere vessel filled with granular matter.
And suppose the objector to refine still further, and to draw the nice distinction that not only parts of tops, but whole tops, when they spin round with their pegs fixed on the spot, are at rest and in motion at the same time (and he may say the same of anything which revolves in the same spot), his objection would not be admitted by us, because in such cases things are not at rest and in motion in the same parts of themselves; we should rather say that they have both an axis and a circumference, and that the axis stands still, for there is no deviation from the perpendicular; and that the circumference goes round.
The earth's great axis spinning on, The never-resting pole of sky -- Let us resolve their Whence and Why, And blend with all things into One; Beyond the bounds of thought and dream, Circling the vasty void as spheres Whose orbits round a thousand years: Behold the Key that fits my theme.
A straight line drawn through the axis of the piece would have passed through the center of the orb of night.
Down, down, they sped, the wheels humming like a top, the dog-cart rocking right and left, its axis acquiring a slightly oblique set in relation to the line of progress; the figure of the horse rising and falling in undulations before them.
Then the astonished eyes of the adventurers saw the great stone door revolve on its axis and swing to one side, leaving a passage open through which they could pass.
At the two extremities of the port, in order that their fires should converge upon the great axis of the ellipsis formed by the basin, in the first place, two batteries had been raised, evidently destined to receive flank pieces, for D'Artagnan saw the workmen finishing the platform and making ready the demi-circumference in wood upon which the wheels of the pieces might turn to embrace every direction over the epaulement.
Screwed at its axis against the side, a swinging lamp slightly oscillates in Jonah's room; and the ship, heeling over towards the wharf with the weight of the last bales received, the lamp, flame and all, though in slight motion, still maintains a permanent obliquity with reference to the room; though, in truth, infallibly straight itself, it but made obvious the false, lying levels among which it hung.
I did not fully understand what she meant, nor am I sure that I do yet, for I have never been to that part of Pellucidar from which the Dead World is visible; but Perry says that it is the moon of Pellucidar--a tiny planet within a planet--and that it revolves around the earth's axis coincidently with the earth, and thus is always above the same spot within Pellucidar.