No marked craters form on the tips and the two carbons are consumed at about the same rate.
It then goes out and to start it the carbons must be brought together and separated.
The white flame-arc obtained by the use of rare-earth compounds in the carbons provides an illuminant closely approximating average daylight.
If two carbons connected to a source of electric current are brought together, the circuit is completed and a current flows.
A million white flame-carbons are being used annually in this country for various photochemical processes.
Calcium fluoride is used in the carbons of the yellow flame-arc which emits excessive red and green rays causing by visual synthesis the yellow color.
This name was continued in use even after the two carbons were arranged in a vertical co-axial position and the arc no more "arched.
This combination operates quite satisfactorily, but sometimes solid carbons are used outdoors.
The first arc-lamps were ordinary direct-current open arcs and the carbons were made from high-grade coke, lampblack, and syrup.
In 1846 Staite discovered that the carbonsof an arc enclosed in a glass vessel into which the air was not freely admitted were consumed less rapidly than when the arc operated in the open air.
Modern carbons for ordinary arc-lamps are generally made of a mixture of retort-carbon, soot, and coal-tar.
This has been taken advantage of in certain modern arc-lamps in which inclined carbons are used.
In the ordinary arc excessive current causes the carbonsto disintegrate rapidly unless they are of large diameter.
The carbonsare 23 millimetres, or upwards of ⅞″ in dia.
In both a single optical agent is employed, and carbons from 15 to 25 mm.
It must not be supposed, however, that investigation of carbonsstopped with these experiments.
Therefore the densest carbons will be most efficient, volume for volume, as gas absorbers in a given space.
This cut the cost of carbons in two, but the improvements tripled the amount of light developed.
Thus the carbon gets the arc which prevents the switches burning, while the switches carry the load to prevent the carbons becoming heated and disintegrated.
The carbons must be adjusted occasionally according to the load they are carrying.
The carbons being separated, the fine wire receives a portion of the current.
At the same time the armature lever L is pulled down and the carbons are separated.
The cut out may be used in this form without any further improvement; but Mr. Tesla arranges it so that if the rod drops and the carbons come in contact the arc is started again.
This clamping and releasing of the rod continues until the carbons are consumed.
The carbons glowed then in both the larger bulbs about as expected, but the smallest did not get its share by far.
A manual switch, for short-circuiting the lamp when the carbons are renewed, is also fastened to the base.
The arc formed with very short separation of electrodes is generally spoken of as a low tension arc and requires very hardcarbons and about 25 volts.
There should, further, be a metal pail or receptacle of some kind for hot carbons taken from the lamps from time to time.
The greater the difference between the two, the better the carbons are assumed to be.
Hand-feed arc lamps are difficult to start under such circumstances and the following method is often resorted to: Place the carbons of all the lamps connected in series the proper distance apart and connect a small fuse across each gap.
The name of the electrical arc lamp is derived from the arch-like appearance of the vapors which give out the light when the carbons are placed horizontally.
The general form of alternating-current arc carbonsis given in Figure 4.
Must be provided with reliable stops to prevent carbons from falling out in case the clamps become loose.
Normally the carbons are in contact and when the switch is closed the current passes through the magnet and carbons.
The act of bringing the carbons of an arc lamp together and immediately separating them and establishing the arc is called striking the arc.
The carbons are incased in a very small wire-mesh enclosure and the whole device is made to slide swiftly down a tight wire leading to the proper place.
Without this aid, trimming is often necessary, and this fact joined to the high cost of the carbons lessens the net gain in their use.
By an exceedingly simple device upon the carbon holding rod, the lamps are extinguished when the carbons are burned out, and injury by burning the holders completely avoided.
The lamp also contains an automatic safety device for preserving the continuity of the circuit in case of accidental injury to the feeding mechanism or the carbons of the lamps.
Now, although the light from the positive pole of the carbons is uniform in quality, it sometimes varies in quantity, as it is difficult to keep its image always in exactly the centre of the slit.
It is, therefore, necessary to 'feed' the carbons towards one another.
The tendency of the arc to wander is also increased, so that cored carbons are essential, and their diameter must be made as small as possible.
The carbons gradually burn away, the rate of consumption of the positive carbon being about twice that of the negative.
In these lamps a number of pairs of carbons is placed in the magazine, and as each carbon is used up, a new one automatically takes its place.
These thin carbons burn away quickly, so that they must be made proportionately longer for the same time of burning.
The arc is made highly luminous by impregnating the carbons with metallic salts, which are volatilized and become incandescent in the arc.
Positive and Negative Carbons] The illustration below represents the two carbonsof the arc light as they appear when cold, the positive carbon being marked + and the negative -.
The central figure is a magnified representation such as can be obtained by throwing an image of the burning carbons on a screen by means of a lens.
File the top ends of the carbons flat and so that they all become equal in thickness, and clamp them in place by means of the brass bolts.
If unable to obtain pieces of carbon of the required dimensions, a number of ordinary electric-light carbons may be used.
The cells are then filled in the ordinary manner, after which the carbons and zincs are raised just far enough to admit a layer of common machine oil, about 3/8 in.
Assuming that ordinary electric-light carbons are to be used, which are about 1/2 in.
While the arcs with plain carbons are bluish-white, those with carbons containing calcium fluoride have a notable golden glow.
With the best vacuum that he could then get by means of the ordinary air-pump, the carbons would last, at the most, only from ten to fifteen minutes in a state of incandescence.
Some of these lights were already in use for large indoor spaces, although the size of the unit, the deadly pressure of the current, and the sputtering sparks from the carbons made them highly objectionable for such purposes.
The great necessity for more durable carbons became a desideratum so urgent that the tireless inventor decided to commission another explorer to search the tropical jungles of the Orient.
At the bottom of the stand which supports the carbons are two small electro-magnets.
The carbons are caused to approach each other by a descending weight, which acts in conjunction with the electro-magnet.
One of them, when the current passes, draws the carbons together, and in so doing throws itself out of circuit, leaving the control of the light to the other.
In the Jablochkoff candle it is necessary that the carbons should be consumed at the same rate.
The carbons gradually waste, while the substance between them melts like the wax of a candle.
Light for light, no doubt, the amount of heat imparted by the incandescent carbons to the air is far less than that imparted by gas flames.
Méritens has recently brought out a new candle, in which the plaster is abandoned, while between the two principal carbons is placed a third insulated rod of the same material.
It is also less because the air cannot penetrate the carbons as it penetrates a flame.
Instead of rods, two large plates of carbons with bevelled edges are employed, one above the other.
You can by no means have the light of the carbons without this invisible emission as an accompaniment.
In this way the dark rays emitted by the incandescent carbons are converted into light rays of all colours.
A momentary contact is established between the two carbonsby a little cross-piece of the same substance placed horizontally from top to top.
A brass chip fastened to the wood keeps the thin rod of carbon in position, and when two copper wires connect the carbons with six to ten jars of a bichromate battery, a light appears where the two carbons meet.
The electric current in passing through the carbons heats the points to a very high degree, producing a brilliant light.
We find manufacturers of fireclay goods now making carbons for electric lighting; we also find gas fixture manufacturers now making and selling electric wires of all kinds, besides other apparatus connected with the electrical field.
The carbons have already been formed, but the first process is that the cotton fiber is carefully tied and wrapped around pieces of carbon, as you see.
You see that the moment the zinc and carbons are placed in the cell electricity is produced, and the lamp is lighted.
The carbonsshow you wrote the name John Borman, not Gorman.
You're supposed to make two carbons of every story you write," she said pityingly.
In her nervousness she inserted one of the carbons upside down, ruining the impression.
When it is desired to keep the arc at the focus of a reflector, both carbons must be fed.
Arc lamps contain some device by which the proper distance between the carbons can be kept.
As the carbons gradually wear away, some device is necessary to keep their ends the right distance apart.
The diaphragm has a constantly varying pull upon it when thecarbons are in any way disturbed by the voice, or by the ticking of a watch, etc.
The extremely small arc due to the peculiar arrangement of the carbons in the Werdermann light has the advantage of offering the least possible resistance to the passage of the current.
In his natural anxiety and haste, Terence fumbled over his task, but at length the carbons fused and the giant beam of the searchlight threw its dazzling rays seaward.
Night had now fallen, and the ghostly white beams of the searchlight swept the shore, the noise of the distant surf mingling with the subdued fizzing of the carbons as Terence diligently attended to the working of the projector.
If in multiple, to produce large current--zincs together and carbons together.
Carbons can be well soaked in warm water and dried in sun, in a place where they will not accumulate dust.
Connect the three zincs together with one piece of wire, and the two carbons with another, taking care that the wire connecting the zincs, does not come in contact with the wire connecting the carbons.
This battery is extremely strong, double as strong as the bottle bichromates sold, as there are more zincs and carbons employed, but it only lasts a short time before needing to be replenished.
Carbons are not affected and last any length of time.
In the enclosed arc lamp, the supply of oxygen in the inner globe is limited and is soon consumed, therefore the carbons last many times longer in such lamps.
Two carbonsplaced in a solution of copper sulphate.
If two carbon rods (electric light carbons answer very well) are placed in a solution of copper sulphate (Fig.
It proved an excellent light, displayed a neat lamp, and gave no ill effects upon either the atmosphere or the eyes; and the perfect carbons showed a surprising endurance.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "carbons" in a variety of sentences. We hope that you will now be able to make sentences using this word.
