It is necessary to insulate the ends or terminals of the secondary heavily with hard rubber, because even dry wood is by far too poor an insulator for these currents of enormous potential differences.
Similar washers, b b, of fibre or other insulating material, serve to insulate the wires from the brass washers.
They were all found to insulate well, except such as acted on the shell-lac of the supporting stem; these were chlorine, ammonia, and muriatic acid.
Periodide of mercury being examined in the same manner, was found most distinctly to insulate whilst solid, but conduct when fluid, according to the law of liquido-conduction (402.
I suggested also that the rotation of a copper globe would probably insulate the effects due to electric currents from those due to mere derangement of magnetism, and throw light upon the true nature of the phenomena.
Thus it was easy to bring the inducteous ball always to the same distance from the inductric bull, and to uninsulate and insulate it again in its place; and then, after measuring the force in the electrometer (1181.
I endeavoured to find some liquids which would insulate well, and could be obtained in sufficient quantity for these experiments.
A] A single paper thus prepared could insulate the electricity of a trough of forty pairs of plates.
The Davy" may be said to insulate the flame of the lamp from the electric matter of the air within the mine.
Don't fail to properly insulate the grid and plate leads.
Don't fail to properly insulate the leading-in wire where it goes through the window or wall.
It was at first thought necessary to insulate the whole length of the wire, and it was not until some time afterwards that it was discovered that naked wires could be successfully employed.
He then inquired how I proposed to insulatethe wires when they were attached to the poles.
Hepburn and I, in 1845, undertook to insulate the line from Lancaster to Harrisburg, Pennsylvania, by saturating bits of cotton cloth in beeswax and wrapping them round projecting arms.
By virtue of its simpler form of winding space, it is easier to insulate and easier to wind, and furthermore, since the shaft does not run through the winding space, it is capable of holding a considerably greater number of turns of wire.
Obviously it is possible to insulate and bury any wire which can be carried in the air.
When insulated with rubber or gutta-percha, no continuous lead sheath is essential for insulation, as those materials, if continuous upon the wire, insulate even when the cable is immersed in water.
The outer surface of the zinc is completely covered on its sides and bottom with heavy pasteboard so as to insulate it from bodies with which it may come in contact, and particularly from the zinc cups of other cells used in the same battery.
Personally, I prefer to insulate both; but in many really good bells only the platinum screw pillar is thus insulated.
With regard to hard Bohemian glass, this is stated by Koeller (Wien Bericht) to insulateten times as well as the ordinary Thuringian soft soda glass.
The kerosene is then removed and its place taken by vaseline or paraffin, known to insulate well as a standard for comparison.
The plates are then built up so as to connect the sheets which require to be connected, and to insulate the other set.
The electroscope will now insulate well enough to show no appreciable collapse of the leaves in one or two hours' time.
The glass which gave the smallest residual charge was an "opal" glass; and flint glasses were found to insulate 105 times as well as soda lime glasses.
These, when dry, insulate almost, but not quite as well as solid paraffin.
Hence one of the greatest tasks of the experimenters has been to find a receptacle that would insulate a cooled substance even partially from the incessant bombardment of heat-impulses from without.
Something, then, must be done to insulate the liquefied gas, else it will retain the liquid state for too short a time to be much experimented with.
In dividing tracks into distinct electrical sections, it becomes necessary to insulate the rail ends at the terminal of each, from those of the adjacent sections.
On account of the considerable difference of pressure between layers, it is necessary to insulate each layer of turns as well as the outside of the coil, as shown in fig.
All attempts to insulate fulminic acid have proved unsuccessful, as it explodes with the slightest decomposing force.
Notwithstanding the striking analogy which exists between common chemical and metallurgic operations, since both are employed to insulate certain bodies from others, there are essential differences which should be carefully noted.
The pans are mounted on iron feet, or short pillars, which insulate them from the floor, and allow their whole surface to be inspected, and any flaw to be repaired.
The attempt to insulate more than one conducting-wire or medium would not only have increased the chances of failure of all of them, but would have necessitated the adoption of a proportionably heavier and more cumbrous cable.
But in the sea the electricity would be instantly dissipated, unless some material could be found which should insulate a conductor sunk in water, as completely as if it were raised in air.
One day in June, 1792, he went to the common at Philadelphia and flew a kite beneath a thundercloud, taking care to insulate his body from the cord.
We can also run bare telegraph wires through it, by taking care to insulate them with glass or porcelain from the wooden poles which support them above the ground.
Its conducting power is low, and Mr. Boys has shown that fine fibres of silica insulate remarkably well, even in an atmosphere saturated with moisture.
A silica rod which had been much handled would probably insulate no better than one of glass in a similar condition.
Or if we take the freedom to put a friend under our microscope, we therebyinsulate him from many of his true relations, magnify his peculiarities, inevitably tear him into parts, and of course patch him very clumsily together again.
Attempts to insulate the line wire were limited to coating it with tar or smearing it with wax for the benefit of all the bees in the neighborhood.
No special precautions were taken to insulate the rails from the earth or from each other.
Insulate the female sex, and they shall discourse upon dress, or the minor affairs of their neighbors, far too exclusively.
The inner end of each key is fitted with an ebonite knob (which is shown at c in the section) to insulate the hand of the operator when using the key.
The effect of the latter operation would be to cut off and insulate the branch cable of the exploded mine, and so prevent any loss of the electrical current, when another mine of that system is required to be fired.
There, in one of those high wicker chairs that insulate their occupants from the world, he saw his tutor leaning back, head a little to one side, and tips of fingers pressed together.
