Pyrenaica, 3 to 6 in., is a pretty dwarf plant, requiring a warm position on the rockwork and a moist, peaty soil more or less gritty; it has rosettes of ovate spreading root-leaves, and large purple, yellow-centred, rotate flowers, solitary, or two to three together, on naked stalks.
The general graphy, principle Arms a and arrangement b, one at eachstation and d B, are connected to the line wire, and are made to rotate simultaneously over metallic segments, 3, 4, and I', 3', 4', at the two stations, so that when the arm a is on segment i at A, then b is on segment I' at B, and so on.
We rotate every twelve months or so, Han explained.
The given series of positions will be assumed in succession if we imagine the laniin~ to rotate first about Jii until Jn comes into coincidence with J21, then about Jar until J24 comes into coincidence with J14, and so on.
As a fist example, suppose we have a flywheel free to rotate about a horizontal axis, and that a weight m hangs by a vertical string ~1~c~g FIG.
It, it, The three lobes of the lower lip of the rotate corolla.
If two magnets having moments M, M' are arranged at right angles to each other upon a horizontal support which is free to rotate, their resultant R will set itself in the magnetic meridian.
The sample, arranged as a bundle of rectangular strips, is caused to rotate about a central horizontal axis between the poles of an upright C-shaped magnet, which is supported near 'its middle upon knife-edges in such a manner that it can oscillate about an axis in a line with that about which the specimen rotates; the lower side of the magnet is weighted, to give it some stability.
But the application of a magnetic field at right angles to the plane of the metal causes the equipotential lines to rotate through a small angle, and the points at] which the galvanometer is connected being no longer at the same potential, a current is indicated by the galvanometer.'
Hence if H varies the magnet will rotate in such a way that the couple due to torsion is equal to the new value of H multiplied by M.
A compound pendulum is a body of any form which is free to rotate about a fixed horizontal axis, the only extraneous force (other than the pressures of the axis) being that of gravity.
We note further that if a body be free to turn about a fixed point 0, there are three mutually perpendicular lines through this point about which it can rotate steadily, without further constraint.
37 rotate about its vertical diameter.
As an example of circular shifting may be cited the motion of the coupling rod, by which the parallel and equal cranks upon two or more axles of a locomotive engine are connected and made to rotate simultaneously.
That, when both pieces rotate, their axes, and all their points of contact, lie in the same plane.
In wheels which rotate continuously for one revolution or more, it is obviously necessary that the pitch should be an aliquot part of the circumference.
Hence also, in any pair of circular wheels which rotate continuously for one revolution or more, the ratio of the numbers of teeth and its reciprocal the angular velocity ratio must be expressible in whole numbers.
The relative velocity pet-pendicular to P~Pi of the teeth at their point of contactthat is, their velocity of sliding on each otheris found by supposing one of the wheels, such as I, to be fixed; the line of centres CXCi to rotate backwards round C~ with the angular velocity aj, and the wheel 2 to rotate round C2 as before, with the angular velocity az relatively to the line of centres CiC2, so as to, have the same motion as if its pitch-circle rolled,on the pitch-circle of the first wheel.
Backs of Teeth and Spaces.Toothed wheels being in general intended to rotate either way, the backs of the teeth are made similar to the fronts.
To make the teeth of a pair of endless screws fit correctly and work smoothly, a hardened steel screw is made of the figure of the smaller screw, with its thread or threads notched so as to form a cutting tool; the larger screw, or wheel, is cast approximately of the required figure; the larger screw and the steel screw are fitted up in their proper relative position, and made to rotate in contact with each other by turning the steel screw, which cuts the threads of the larger screw to their true figure.
Coupling of Parallel AxesOldhams CouplingA coupling is a mode of connecting a pair of shafts so that they shall rotate in the same direction with the same mean angular velocity.
If the axes of the ~ shafts are in the same straight line, the coupling consists in so connecting their the same straight line combinations of contiguous ends that they shall rotate as one piece; but if the axes are not in C
Linkwoyk in GeneralThe pieces which are connected by linkwork, if they rotate or oscillate, are usually called cranks, beams and levers.
Coupling of Parallel Axes.Two or more parallel shafts (such as those of a locomotive engine, with two or more pairs of driving wheels) are made to rotate with constantly equal angular velocities by having equal cranks, which are maintained parallel by a coupling-rod of such a length that the line of c000exion is equal to the distance between the axes.
When the cones are pressed together or engaged, their friction causes the pulley to rotate along with the shaft; when they are disengaged, the pulley is free to stand still.
Barlow, Sturgeon and others then showed that a copper disk could be made to rotate between the poles of a horseshoe magnet when a current was passed through the disk from the centre to the circumference, the disk being rendered at the same time freely movable by making a contact with the circumference by means of a mercury trough.
Although the two-type beds have a reciprocating motion, as in the ordinary one-sided press, the two cylinders rotate towards each other.
P. 392), who prefers to rotate the cathode at a speed that maintains a peripheral velocity of at least woo ft.
Rumford then turned up a hollow cylinder which was cast in one piece with a brass six-pounder, and having reduced the connexion between the cylinder and cannon to a narrow neck of metal, he caused a blunt borer to press against the hollow of the cylinder with a force equal to the weight of about ro,000 lb, while the casting was made to rotate in a lathe.
(?) and viii., and the satellite of Neptune.); while, to make the argument complete, the planets, so far as they can be observed, rotate on their axes in the same manner.
As this vast mass cooled it must by the laws of heat have contracted towards the centre, and as it contracted it must, according to a law of dynamics, rotate more rapidly.
Faraday and others then discovered, as already mentioned, means to make the conductor conveying the current rotate round a magnetic pole, and Ampere showed that a magnet could be made to rotate on its own axis when a current was passed through it.
When the clutch is moved towards the hoop, its arms catch those of the hoop, and cause the hoop to rotate and to communicate its rotation to the pulley by friction.
The elastic resistance evoked by this deflexion is proportional to the deflexion, so that if c is a constant depending upon the form,, material and, method of support of the shaft, the following equality must hold if the shaft is to rotate stably at the stated speed- -~ (y+e)ai=cy, from which y=Wafe/(gcWa2).
The corresponding value of a, namely ~ gc/w, is called the critical velocity of the shaft, and is the speed at which the shaft ceases to rotate stably and at which centrifugal whirling begins.
Suppose, for example, that a flywheel is rotating with angular velocity n about its axis, which is (say) horizontal, and that this axis is made to rotate with the angular velocity ~ in the horizontal plane.
As a first application of the equations (2) take the case of a solid constrained to rotate with constant angular velocity to about a fixed axis (1, m, n).
This circle to measure the polar distance of any star seen in the telescope, and these readings will also be true (apart from the effects of atmospheric refraction) if we rotate the instrument through any angle on the axis A A.
Other water engines, similarly connected, with keys at the observer's hands, rotate the dome and perform the quick motions in right ascension and declination.
In Se p tember of that year he discovered that the force required for the rotation of a copper disk becomes greater when it is made to rotate with its rim between the poles of a magnet, the disk at the same time becoming heated by the eddy or "Foucault currents" induced in its metal.
If the experiment was successful the table would rotate with considerable rapidity, and would occasionally rise in the air, or perform other movements.
Palustris, is a perennial plant growing to a height of 6 to 18 in., with rootstock creeping, stem clothed with lax spreading hairs, leaves light green, and somewhat shining, buds pink, becoming blue as they expand, and corolla rotate, broad, with retuse lobes and bright blue with a yellow centre.