Fuse

“ Even in the midst of the swing he checked, glanced once at the spitting fuse, and with a stoop and a heave flung the officer out over the front parapet, leaped on the firing step, and hurled himself over after him.
It must be remembered that the burning fuse of a bomb gives no indication of the length that remains to burn before it explodes the charge. The fuse looks like a short length of thin black rope, its outer cover does not burn and the same stream of sparks and smoke pours from its end in the burning of the first inch and of the last. ”

“ To Ned, Bob, and Jerry, as well as to other soldiers who had taken part in the Great War, the word “fuse” referred to but one thing, and that was the explosion which usually followed the lighting of it. The lads were familiar with many kind of fuses, from the ordinary time one, the most common form of which is the fizzing string attached to a firecracker, to the complicated fuses in the big shells. These may be set to explode the shell at any height, or at any time desired. ”

“ When all is ready the tools are removed to a safe distance, a lighted lamp is touched to the fuse, the men cry “Fire!” to warn all who may be in the vicinity, and, retreating down the chamber, they take refuge behind some convenient pillar. The fuse burns so slowly that the men have ample time in which to get out of harm’s way, if ordinary care is taken. ”

“ A, Fuse-Block with plain Wire Fuse. D, Fuse-Block with Mica Fuse in position. When a fuse burns out in a trolley car or in a light or power circuit, it is because a greater amount of current is trying to pass than the circuit can safely carry. If a fuse were not placed in such a circuit so as to shut the current off before the danger point is reached, any electrical device might become "burned out," or in extreme cases, the wires become so hot as to cause a serious fire. ”

“ Paradis sharply bows his head and we follow suit. "The fuse!—it has gone over." The shrapnel fuse goes up and then comes down vertically; but that of the percussion shell detaches itself from the broken mass after the explosion and usually abides buried at the point of contact, but at other times it flies off at random like a big red-hot pebble. One must beware of it. It may hurl itself on you a very long time after the detonation and by incredible paths, passing over the embankment and plunging into the cavities. ”

“ A fuse for igniting an explosive by electricity. There are two kinds. In
one a thin wire unites the ends of the two conducting wires as they
enter the case of the fuse. The larger wires are secured to the case, so
that no strain comes on the fine wire. On passing a current of
sufficient strength the small wire is heated. ”

“ If the fuse, 2, in the middle wire be made, say, one-half the capacity of each of the other fuses, this condition will be relieved by the blowing of this fuse, and as the lamps in the live circuit would not be anywhere near candle power if the circuit remained intact, the blowing of the middle fuse will not be any disadvantage to the user of the lamps. ”

“ Now, an electric fuse is what an electrical engineer might almost unconsciously carry about with him, it is so essential a part of his working tools, but it is a thing that a literary man or a press reporter could have no possible use for."
"Exactly, exactly. And it was no doubt, that bit of electric fuse that turned your thoughts to the one house in the neighbourhood lighted by electricity, and suggested to your mind the possibility of electrical engineers turning their talents to account in that direction. ”

“ This detachment can easily be effected by Bickford’s fuse. Here, whilst I think of it, never attempt to ignite a Bickford fuse with anything else than the flame of a port-fire or a blue-light. The chief beauty of any firework device consists in working to exact time. A Bickford fuse cannot readily be set on fire with a match-flame. You may crack many lucifers over the job without succeeding; your balloon, that ought to be off on its travels, all the time kept waiting.
Fig. ”

“ The fuse of the bomb is represented by c d, fig. 17. It is generally a conical tube, formed of beech, willow, or some dry wood, and filled with a composition of sulphur, salt-petre, and mealed-powder. The bomb being charged, this fuse is inserted in the cavity through the fuse-hole; and when fired, communicates the fire to the powder in the shell.
The fuses for bombs are charged with great care, that nothing may prevent them from communicating the fire to the powder in the centre of the bomb. They are driven into the shell so as that only about an inch and a half comes out beyond the fuse-hole ”

“ In the shaft we were obliged to blast, as I said before. This was done by drilling holes in the rock, which were then loaded with the blasting powder, the fuse inserted, and then the hole tamped down hard and fired. The firing was done by lighting a bit of candle over the flame of which we bent the fuse. While the easing of the fuse was burning through whoever fired the shot would have plenty of time to put his foot in the hook, shake the rope and be hoisted up out of danger. ”

“ The first section from the end of the fuse was marked "6;" the next section "5" and so on down to the section nearest the bomb, which was divided by the marks "1"—"1/2"—"1/4."
"I see," said Josie, nodding her head with intelligent perception. "Each section, when lighted, will burn for one hour, running along its groove but harmless until the end of the fuse is reached. If the entire fuse is lighted, it will require just six hours to explode the bomb, while if it is cut off to the last mark and then lighted, the bomb will explode in fifteen minutes. ”

“ When the safety fuse burns down into the cap, or when, in the other case, the priming of the electric fuse is fired, the fulminate explodes and causes the detonation of the charge in which it is placed.
Firing Machines and Batteries. —The electrical machines used for firing tension fuses are of two kinds. In one kind, the electricity is excited by [56] friction, and stored in a condenser to be afterwards discharged by suitable means provided for the purpose. In the other kind, the electricity is excited by the motion of an armature before the poles of a magnet. ”

“ A. One which prevents the escape of powder-gas through the vent. (It need not necessarily be screwed into the vent.)
Q. What are percussion-primers?
A. Such as are used in fixed ammunition and go off by the snap of the firing-pin. They are commonly called caps.
Q. What are high- and low-resistance fuses?
A. A high-resistance fuse is one that requires a high initial velocity to cause the plunger to be released, and is therefore safer in handling. A low-resistance fuse does not require such a high initial velocity to cause it to act. Low-resistance fuses are provided with "safety-wires." ”

“ An electric fuse consists of a charge of an explosive compound suitably placed in the circuit of an electric current, which compound is of a character to be acted upon by the current in a manner and in a degree sufficient to produce explosion. The mode in which the current is made to act depends upon the [48] nature of the source of the electricity. That which is generated by a machine is of high tension, but small in quantity; while that which is generated by a battery is, on the contrary, of low tension, but is large in quantity. ”

“ The short time fuse has red threads in it, the long time fuse hasn't. If the German sees that there are none of these red threads in the fuse of the grenade that drops near him he figures he's got time to throw it back. ”

“ A fuse is a protective device that prevents an overload of electricity. Our defense mechanisms are analogous devices that protect us against emotional overload. When an emotional fuse burns out, it is often because we have maintained defenses too long in the face of increasing inner frustration and pain. The result may involve severe depression, incapacitating anxiety, or serious withdrawal. ”

“ The apex has a screw plug of larger diameter than that of the fuse. This is shown in Fig. 4. The fuse is a direct action one. The needle, B, is held in the center of a copper disk, C C, and is safe against explosion until it is actually brought into contact with an object, when it is forced down, igniting a patch of cap composition and the magazine at A, and so firing the bursting charge of the shell below. E E E are each priming charges of seven grains of pistol powder, made up in shalloon bags to insure the ignition of the bursting charge, which is in a bag of serge and shalloon beneath. ”

“ It is many years since I had occasion to work with Bickford’s fuse, so I forget its rapidity of burning. It does not signify; when you have got your fuse you can try an experiment with any convenient length, timing the rapidity of burning by a watch.
Quickmatch consists of a paper tube with a rapidly inflammable wick running through it, the intention being that flame applied to one end of the match shall flash to the other, and instantaneously. The actual fireworks I recommend you to get are some blue-lights, some Roman candles, a few Catherine wheels, crackers, and maroons. ”

“ These melt and cut off the current whenever too much passes for the copper conductor to carry without getting hot. The fuse wire melts at about six hundred degrees, while the copper will not melt until it reaches nearly two thousand degrees. This temperature is sufficient to set fire to wood, paper, and cloth. When any fuse melts, the current is cut off from all chandeliers, etc., in the particular circuit controlled by the fuse. This produces consternation among people who do not understand the function of a fuse. ”

“ They should be spherical, only, instead of a hole for the fuse, as in a hollow shot, they should have a neck like a bottle, with a cap to screw over—not in—the neck. The case should be charged through the neck, and the wires let in through two holes, counter-sunk, diametrically opposite, the counter-sinking being for the purpose of receiving pitch or other resinous matter to keep the water out. The fuse, being adjusted to the wires, should be held in its place by a string through the neck, while the wires are drawn out taut and sealed within and without. ”

“ If the load is not in excess of six amperes, a six ampere fuse will carry it as readily as a twenty ampere fuse. If a short circuit occurs the twenty ampere fuse will blow as readily as the six ampere fuse and, in addition, will cause destruction of a socket or whatever may be the cause of the trouble as well as an increased fire hazard. ”

“ A fuse is simply a strip of fusible metal, often consisting of lead with a small percentage of tin, connected in series in the circuit.
Experiments have shown that for large fuses, a multiple fuse is more sensitive than a single one. A one hundred ampere fuse may be made by taking four wires of twenty-five amperes capacity. A fuse block may be overloaded, not because the metal of the terminals is not of sufficient cross section to carry the current, but because of insufficient area of, contact, or loose contact of fuse and wires ”

“ For brilliant effects arc-lamp illumination is necessary and the arc must of course be below the water. As arc lamps when tilted upward break condensers very rapidly, the light is usually reflected upward by means of mirrors set as indicated in Figure 197.
Fuses. Fuses.—There is no part of the electrical equipment of a traveling production so much abused as the fuse. It is provided primarily for the protection of apparatus and should never be of greater capacity than is needed to carry the load put upon it. There is nothing whatever gained by the use of larger fuses. ”

“ A keg is then opened, and the end of a quarter-inch fuse imbedded in the powder. This fuse is inclosed in boxes, six or eight feet in length, which serve to protect it, while the men are tamping. The fuse being thus inclosed, tampingcommences. Thedirtthat came from the drift was first carefully packed around the boxes that protect the fuse, and then throughout the drift. Tamping finished, the fuse is lighted at leisure, and the blast goes off.
In most instances, a blast is successful, but occasionally one will blow out, leveling every thing that may stand in its way. ”

“ The spaces given are correct for fuse blocks to be used on direct-current systems, and can therefore be safely followed in devices designed for alternating currents. If the copper fuse tips overhang the edges of the fuse block terminals, the spacings should be measured between the nearest edges of the tips.
A space must be maintained between fuse terminals of the same polarity of at least one-half of an inch for voltages up to 125 and of at least three-quarters of an inch for voltages from 125 to 250. ”

“ The temperature of the surrounding air or other substances affects the melting current greatly, because the rate at which heat from the fuse will be transferred to the surroundings depends upon the difference of temperance between them and the fuse. Hence a fuse in a warm place will be melted by a smaller current than a similar fuse in a cold place. ”

“ Gun-cotton requires a much stronger charge of fulminate than dynamite.
Fig. 35.
In the electric fuses illustrated, the metal case shown is the detonator, the fuse being placed inside above the fulminate. When safety fuse is used, the end is cut off clean and inserted into the cap, which is then pressed tightly upon the fuse by means of a pair of nippers, as shown in Fig. 35. When water tamping is used, and when, with ordinary tamping, the hole is very wet, a little white-lead or grease must be put round the edge of the cap as a protection. The electric fuses are always made waterproof ”

“ A hundred feet of wire looped back and forth in a one-inch span across the terminal lugs would produce a mighty overload. It made a bulky bundle of wire the very mass of which would prevent it from heating to incandescence and blowing out in a shower of droplets.
One chance in a million!
Just one!
Walt snapped the switches on.
For to the trained technician, a blown fuse is not an ill. It is a symptom of an ill, and no trained technician ever replaced a blown fuse without attempting to find out why and where the overload occurred. ”