There is some prospect of the luminosity excited in a vacuum tube by the alternating currents from a dynamo or an induction coil becoming an illuminant.
The vacuum in the bulb is made by a mercurial air pump of the Sprengel sort, and the pressure of air in it is only about one-millionth of an atmosphere.
Crookes has obtained exquisitely beautiful glows by the phosphorescence of gems and other minerals in a vacuumbulb like that shown in figure 69, where A and B are the metal electrodes on the outside of the glass.
G is a small tube leading from the bottom of the cylinder to the center of the axle, and from thence brought out at the end of it, and by which the air is extracted from the cylinder by means of an air pump and a vacuum formed in it.
Strutt (Lord Rayleigh), devised a radium clock to run on this principle, consisting of a vacuum vessel in which was suspended a radio-active substance contained in a tube.
The black coloration upon the surface produced by this process, as also by the electric bombardment in a vacuum tube, appears to be due to a conversion of the surface film into graphite.
He closed a switch that lighted another bank of vacuumtubes behind the control panel.
The vacuum tubes of the transmitter glowed into life and the scientist manipulated the controls rapidly.
Without more ado, he lifted from a small frame one of the vacuum vessels referred to.
In a double vacuum vessel the centre of which was an open test tube, and the second compartment a reservoir of liquid oxygen connected with an exhaust pump, he so lowered the pressure that the oxygen boiled tumultuously.
I found the cheapest and best method of getting a vacuumto be the old Torricellian one of driving out the air with mercury vapor and then condensing the vapor.
After various trials and experiments, we devised a set of vacuum vessels, each consisting of a tube or bottle for the liquid oxygen, sealed at the neck in a second tube or bottle, from which the air had been exhausted.
This vacuum method," he says, "of transmitting power dates from the time of Papin; but it remained a dead contrivance for about a century until it received the masterly touch of Murdock.
He observed the admirable system, which he had invented, of transmitting power from one central engine to other small vacuum engines attached to the several machines which they were employed to work.
It is also identical with the cathode ray of the vacuum tube.
Again it is easy to show that even in the oldest haloes the quantity of helium involved is so small that one might say the halo-sphere was a tolerably good vacuum as regards helium.
This vacuum, the negative in relation to the affirmative, is also the principle of the movement of atoms; they are so to speak solicited by the vacuum to fill up and to negate it.
In abstract existence, nature has its ground in itself and is simply for itself; the atom and the vacuum are just such simple Notions.
Atoms thus are, even in their apparent union in that which we call things, separated from one another through the vacuum which is purely negative and foreign to them, i.
For neither fancy nor reflection can long continue in the vacuum of mystery.
Causing liquid ethylene to boil in an air-pump vacuum at -103° C.
The depression is generally less in a vacuum than in the air, so that a syphon barometer gives results too high, and the more so as the tube is smaller.
This causes a momentary vacuum to be formed under the paper, and the pressure of the air above, which is about 15 lb.
The uncoiling causes a slight vacuum in the hose and the liquid follows it up and starts the flow instantly.
An Interesting Vacuum Experiment [Illustration] A very interesting experiment may be performed with two drinking glasses, a small candle end and a piece of blotting paper, says the Pathfinder.
The construction of the puller vents the cork as it enters and thus no vacuum is created.
When exhaled through the mouth or nostrils, it leaves a vacuum which is filled up by other air finding a way in through the pores, this air being thrust out of its place by the exhalation from the mouth and nostrils.
The exhalation of the breath through the mouth and nostrils displaces the external air, and at the same time leaves a vacuum into which through the pores the air which is displaced enters.
Thus we see that this singular theory is dependent on two principles largely employed by Plato in explaining the operations of nature, the impossibility of a vacuumand the attraction of like to like.
Also the vacuum which is made when the air is exhaled through the pores is filled up by the inhalation of breath through the mouth and nostrils.
The velocity of the liquor through some of these machines is so great that occasionally no vacuum is used.
Steam generated from the spent bark is used to heat the extracting vats, and to work a vacuum pan or evaporator whereby more water can be used and a more complete as well as a more rapid extraction obtained.
A great stride forward was made by Howard's invention of the Vacuum Pan.
With such weak materials the extract manufacturer has had to secure a much more complete extraction than in ordinary leaching, and to concentrate his infusions by means of steam-heated vacuum pans.
For evaporation a double-effect vacuum pan is preferred, which operates first at about 113 deg.
Apart from the capital cost of a condenser the chief cost of maintaining a vacuum is in pumping the circulating water, of which up to 70 lbs.
The lonesomeness of the Big Vacuum was getting grimed into him.
Remembering his first trip, long ago, from the Moon to Mars, he knew how gentle the Big Vacuum could sometimes seem, with just a skin of stellene between it and himself.
And was the ripped, transparent casing of its body and limbs another version of a vacuum armor?
He thought that sometime, surely, perhaps soon, the Big Vacuumwould finish him.
Now that the price had been shoved down into the ground, they could probably get their Archer Fives--their all-important vacuum armor.
The actual landing still had to be made in the only way possible on worlds whose air-covering was so close to a complete vacuum as this--like a cat climbing down a tree backwards.
Then, what was left had been preserved in a vacuum through sixty millions of years.
The Big Vacuum ain't so tough--no storms in it, even, to tear our bubbs apart.
No doubt, her mind was also on the Big Vacuum beyond the Earth.
Pneumatics) Defn: The glass vessel in which the vacuum is produced, and the objects of experiment are put, in experiments with an air pump.
Siphon condenser, a condenser for a steam engine, in which the vacuum is maintained by the downward flow of water through a vertical pipe of great height.
Physics) Defn: Any of the rays produced when cathode rays strike upon surface of a solid (as the wall of the vacuum tube).
It was intended to be exactly, and is very nearly, equivalent to the weight in a vacuum of one cubic centimeter of pure water at its maximum density.
Vacuum gauge, a species of barometer for determining the relative elasticities of the vapor in the condenser of a steam engine and the air.
Vacuum brake, a kind of continuous brake operated by exhausting the air from some appliance under each car, and so causing the pressure of the atmosphere to apply the brakes.
Vacuum valve, a safety valve opening inward to admit air to a vessel in which the pressure is less than that of the atmosphere, in order to prevent collapse.
I return therefore to my Subject, and say that there being no Vacuumin the World; No Vacuum in the World!
John's tendency to abhor the vacuum of success was corrected by the arrival of Maud, the parlor-maid, whose statuesque anemia and impersonal neatness put something in it.
Most of the salt used on our tables is made by the vacuum process or by an improved method which produces tiny flakes of salt similar to snowflakes.
The condensed water occupies less space than the steam and so maintains the vacuum in the pan.
For a perfect vacuum the brine is boiled at less than 100° F.
Crude glycerine is distilled under vacuum with the aid of superheated steam.
The vacuum to be used will, of course, depend upon the heat of the fire and still, but as a general rule good results are obtained with an 18 inch vacuum.
The intimation is made that were it possible to make the vacuum more perfect, there would arise out of this invisible gas, spontaneous manifestation of energy; or matter would be resolved into force.
If the vacuum be made more perfect, and only ten atoms remain, the ten still occupy the whole space; and if the process could be carried so far that only one remained, it would still fill the space.
