The chief source of uncertainty in the observation lies in the torsion of the suspension fibre, usually of silk or more rarely of phosphor bronze or other metal.
The method has been employed by the authors themselves in studying the effects of tension, torsion and circular magnetization, while R.
The effects of magnetization upon the torsion of a previously twisted wire, which were first noticed by Wiedemann, have been further studied by F.
Near a magnetic pole the directive force on the declination magnet is reduced, and the effects of torsion are correspondingly increased.
Slubbings intended for warp-yarn must be more twisted than those for weft; but each must receive a degree of torsion relative to the quality of the wool and of the cloth intended to be made.
Arkwright, which till within these 14 years was the principal machine for communicating the incipient torsion to the spongy cord furnished by the drawing heads.
Before any degree of torsion therefore be communicated, a previous process is required to give the filaments a level arrangement in the ribands.
Ligation andtorsion of the cut end of large blood-vessels should be practised.
The instrument can be provided with a curve or table showing the current corresponding to each angular displacement of the torsion head.
This second coil is suspended by a number of silk fibres, and to the coil is also attached a spiral spring the other end of which is fastened to a torsion head.
If then the torsion head is twisted, the suspended coil experiences a torque and is displaced through FIG.
It has the disadvantage of not being direct reading when made in the usual form, but can easily be converted into a direct reading instrument by appropriately dividing the scale over which the index of the torsion head moves.
This tendency can be resisted by giving a twist to the torsion head and so applying to the movable coil through the spring a restoring torque, which opposes the torque due to the dynamic action of the currents.
In seeking the origin of the disturbed motion of the torsion rod Cavendish made a very important observation.
He further saw that reduction in length of the torsion rod with given balls is an advantage.
Ultimately he found that this was due to convection currents in the case containing the torsion rod, currents produced by temperature inequalities.
These were suspended from the top of the case which could be rotated round the central tube, and they were arranged so that the radius to the centre from the axis of the torsion system made 65 deg.
A notable feature of the work consisted in the suspension of the torsion apparatus in a receiver exhausted to about 4 mm.
Let 2a be the length of the torsion rod, m the mass of a ball, M the mass of a large sphere, d the distance between the centres, supposed the same on each side.
The size of the float was adjusted so that the torsion fibre of quartz 35 cm.
The torsionrod mirror reflected a distant scale by which the deflection could be read.
In the course of investigations on local variations of gravity by means of the torsion balance, R.
But the moment of the attracting force is halved only, so that the deflection against one-fourth torsion is doubled.
For if the rod be halved the moment of inertia is one-fourth, and if the suspending fibre is made finer so that the torsion couple per radian is also one-fourth the time remains the same.
Now let the attracting masses be put one at each end of the torsionrod with their centres in the line through the centres of the balls and d from them, and let T2 be the time of vibration.
Wilsing, in which a vertical "double pendulum" was used in place of a horizontal torsion system.
Baille consists of an annealed silver torsion wire of 2.
Heat also has a disturbing effect, and makes itself felt in the torsion of the fiber and the cage surrounding the lever.
The lever placed at equal distances from the fixed balls communicates, by the medium of the torsion wire, with the positive pole of a battery, P, the other pole being to earth.
At the beginning and end of the stroke when the crank is vertical, no force of torsion can be exerted on the crank shaft by the crank, but this force is at its maximum when the crank is horizontal.
How is the strength of a cast iron shaft to resist torsion determined?
And, finally, will this torsion of the body of the snail perhaps account for the spiral nature of the shell?
They may be called the typical gasteropods, the shell being univalvular and generally spiral, and the animal exhibiting the singular torsion of the visceral mass which has placed the breathing-organs forward of the heart.
There is a group of these prosobranchs which gives evidence of an inferior degree of that visceral torsion which is always found in the gasteropods.
It also has two gills, the degree of torsion in the visceral mass not being sufficient to have crowded out and destroyed the original right gill.
From the knowledge of this torsion the rigidity can be deduced.
With regard to the slight oscillations of torsion which he has specially studied, M.
It is known that Cavendish was the first who succeeded by means of the torsion balance in effecting fairly precise measurements.
He took two equal weights of a salt of radium and a salt of barium, which he made oscillate one after the other in a torsion balance.
Until further discoveries are made, a single fact becomes prominent from the examination of this character--that is, that the torsion appears to be greater in white races than in black and yellow.
This torsion is measured by the angle of torsion, which is taken either according to Broca's method or Gegenbaur's.
The torsion of the humerus--that is to say, the degree of rotation of the lower part of this bone in relation to its upper part, is a character of a certain seriate value; but it is of no use in the differentiation of races.
These are entirely unaffected by the torsion of the interorbital part of the skull.
Footnote 37: This moment of torsion needs a supplementary correction, on account of the vertical electric attraction of the excited disks.
In 1785 Coulomb constructed his torsion balance, by which he was enabled to measure the repulsion of electrified bodies.
Coulomb was the maker of the first instrument for measuring a current, which was known as the torsion balance.
When he discovered that the elasticity of torsion of a wire was a constant property, he proceeded to utilize it in the calculation of such delicate phenomena as those of electric and magnetic forces.
The instrument depends on the principle first established by Coulomb himself, that when a wire is twisted, the angle of torsion is directly proportional to the force of torsion.
In the cotton mantle, the tight twisting of the fibre brings this torsion into play.
The amount of torsion necessary to re-establish equidistance expressed the magnetic difference of the substances compared.
The amount of charge in each jar was determined by bringing a proof-plane into contact with its knob and measuring by a torsion balance the charge taken away.
I was anxious to obtain wires which would preserve this structure against the destructive influence of torsion and vibrations, so that I could constantly employ the same wires without the comparatively long and tedious process of preparation.
Its free motion differs entirely from that given it by torsion or stress.
The angle through which the pointer of the torsion screw was turned is directly proportional to the square root of the angle of torsion.
A pointer H is attached to the torsion screw D, and sweeps over the scale of the dial.
Upon the combined effect of the magnetic attraction of the current which tends to deflect the needles, and the torsion in the suspension fibre which tends to keep the needle at the zero position.
Upon the strength of the field of the permanent magnet, the number of turns in the suspended coil, and the torsion of the wires by which it is suspended.
To determine the current strength in amperes, the square root of the angle of torsion is multiplied by a calculated constant furnished by the makers of this instrument.
It might be supposed that the torsion of the wire would appreciably affect the result.
LK supports the wire and disk: ag is the brass wire, the torsion of which causes the oscillations; DS is a graduated disk serving to measure the angles through which the apparatus oscillates.
The support g, which carries the apparatus, also receives in a tubular guide the end of the torsion rod gr and a set screw for fixing the upper end of the torsion rod when necessary.
Let R be the radius of the disk, and b its leverage, or the distance of its centre from the axis of the torsion rod.
Let r be the radius of the torsion rod, l its length from the needle over ef to r, and [alpha] the observed torsion angle.
When the disk is rotated to any given angle, it oscillates under the action of its inertia and the torsion of the wire.
In the actual instrument the torsion rod was a brass wire 0.
The impulse of the stream of water is received on a circular disk x, in the plane of the torsion rod and the frame abcd.
When the apparatus is nearly in its right position, the set screw at g is made to clamp the torsion spring.
The torsion rod will be unstrained, and the needle will be at zero on the graduated circle.
The central vertical rod gr forms a torsion rod, being fixed at r to the frame abcd, and, passing freely upwards through the guides, it carries a horizontal needle moving over the graduated circle ef.
This law was established and proved by Coulomb by means of a delicate instrument known as the Torsion Balance, with which he also established the law of inverse squares.
This law was proved by Coulomb by means of an instrument known as Coulomb's Torsion Balance, and I must refer the reader to any work on electricity for a full establishment of this law.
This change may be brought about by arrest of development, by increased development of parts or by a torsion of the axis.
In the bud of the screw-pine the leaves are arranged in three orthostichies with the phyllotaxis 1/3, but by torsion the developed leaves become arranged in three strong spiral rows running round the stem.
The strength of a shaft to resist torsion is the cube of its diameter in inches, multiplied by the strength of the material of which the shaft is composed, per square inch of cross-sectional area, giving the strength in statical foot-pounds.
