Safety lamp

“ If the lamp is allowed to remain too long in such a fiery atmosphere, it becomes dangerous, because the gauze, becoming heated to redness, may fire the external gas. For detecting the presence of fire-damp in amounts less than 21/2%, special lamps with non-luminous flames are adopted. In Pieler’s lamp, which is of the ordinary Da form, alcohol is burned on a silk wick, and a screen is provided so that the flame can be hidden. When exposed in air containing 1/4% a cap of 11/8 in. is formed, which increases to 2 in. with 1/2%, and with 11/4% the lamp is filled with a deep blue glow. ”

“ The glow-lamp in process of manufacture before you is now being unsealed from the pump; it is now exhausted, and we will pass a current through it so as to raise it to incandescence. The current is now on, and you see the lamp burns with full brilliancy. The next experiment is rather a cruel one, because it is willful destruction. I will not destroy the lamp that has just been made before us, for I will keep it as a memento of this evening. I want to show the safety of the electric lamp. Many people imagine that there is a great deal of danger about it. ”

“ The air for supplying the flame, entering at the bottom of the gauze and passing down the inner side of the glass, protects the latter to some extent from becoming overheated, but a large amount of light is lost by absorption in the glass, so that there is no great advantage over the ordinary Davy lamp to compensate for the extra weight and cost, especially as the safety property of the lamp depends upon the glass cylinder, which may be readily broken when subjected to the ordinary accidents of working. ”

“ George Stephenson for having discovered the fact that inflamed fire-damp will not pass through tubes and apertures of small dimensions, and having been the first to apply that principle in the construction of a safety-lamp calculated for the preservation of human life in situations formerly of the greatest danger, was presented to him at a general meeting of the subscribers, Charles John Brandling, Esq., in the Chair. ”

“ Types of Safety Lamps.
"Yes; because enough air, or oxygen must go through the mesh to support combustion of the flame itself. If it does not get enough it is smothered."
"Then why not make a lamp of that kind?"
"But where can we get enough gauze to make a cylinder big enough to go around a lamp?"
John laughed at the serious predicament, which expressed itself in the faces of the boys. "That is true," he said; "but if we can get a small piece ofp. ”

“ The glass keeps the flame from ever touching the innermost gauze, and, if an accident happens—such as the breaking of the glass—it would still be fairly safe, for the burning gas inside wouldn't pass through the inner gauze until that got red-hot, and it wouldn't reach the outer gauze because the current of air passing down between the two layers of wire mesh would keep the outer gauze cool. This safety-lamp was invented by Sir Humphry Davy, in England, in 1815, just after a big explosion in an English colliery had cost hundreds of lives. ”

“ Gray, the present Bishop of Bristol, addresses a letter to Sir H. Davy, and invites his attention to the subject.—Sir H. Davy's reply.—Farther correspondence upon the possibility of devising means of security.—Sir H. Davy proposes four different kinds of lamp for the purpose.—The Safe-lamp—The Blowing-lamp—The Piston-lamp—The Charcoal-lamp.—His investigation of the properties of fire-damp leads to the discovery of a new principle of safety.—His views developed in a paper read before the Royal Society on the 9th of November 1815.—The first Safety-lamp. ”

“ Individual lamps are usually of small size, and burn oil; they may be carried in front of the miner’s helmet, or be fixed to standards, which can be set up close to the work being done by each man. Miners’ safety lamps should be employed where there is danger from gas. ”

“ Other approved lamps are the Deflector and those of Marsaut and Mueseler when specially bonneted to resist extra high-speed currents. The illuminant now generally used in Great Britain is a mixture of rape oil with half its volume or more of petroleum, which is more suitable than vegetable or animal oil alone. ”

“ For, if the light furnished is insufficient, there will be strong efforts made to replace the small lamps by larger ones. Guards are also necessary as a protection against fire. Actors are in the habit of drying small articles of clothing on the lamps, and fires have been known to start from this cause. The guards on the lamps throw shadows on the faces of the actors, and for this reason are not liked. In order to avoid the shadows, frosted lamps may be used, or two lamps on each side of the mirror. One lamp will then illuminate the shadows caused by the other. ”

“ From an artistic point of view, one of the worst methods of lighting a room is by pendant lamps, collected in single centres in large numbers. The lights ought to be distributed in different portions of the room, and so shaded that the light is received only by reflection from surrounding objects. Ornamental effects are frequently produced by means of candle lamps in which a small incandescent lamp, imitating the flame of a candle, is placed upon a white porcelain tube as a holder, and these small units are distributed and arranged in electroliers and brackets. ”

“ I am sure it will afford you satisfaction to learn that the lamps still continue to give the most gratifying proofs of the advantages resulting from their invention, and that not a single inch of human skin has been lost by fire, wherever they have been used.
Sir Humphry has just made another important improvement in the lamp, by constructing the cylinder of twisted wire-gauze. Lamps thus constructed, possess the singular property of not becoming red-hot, under any circumstances of exposure to explosive mixtures, whether urged by a blast, or in a state of rest. ”

“ In the use of the lamp for domestic purposes only soft well-fitting wicks should be employed, and the lamp should be filled with oil each day so as never to allow it to burn too low and so leave a large space above the surface of the oil in the reservoir. The lamp should never be moved whilst alight, and it should only be put out by means of a proper extinguisher or by blowing across the top instead of down the chimney. By these means the risk of accident would be so reduced as to compare favourably with other illuminants. ”

“ Of these inventions, the Safe lamp, which is the simplest, is likewise the one which affords the most perfect security, and requires no more care or attention than the common candle, and when the air in mines becomes improper for respiration, it is 86 extinguished, and the workmen ought immediately to leave the place till a proper quantity of atmospheric air can be supplied by ventilation. ”

“ For indoor, public room or factory lighting, inverted arc lamps are sometimes employed. In this case the positive carbon is the lower one, and the lamp is carried in an inverted metallic reflector shield, so that the light is chiefly thrown up on the ceiling, whence it is diffused all round. The alternating-current arc is not only less efficient in mean spherical candle-power per watt of electric power absorbed, but its distribution of light is disadvantageous for street purposes. ”

“ The lamps themselves are attached to some variety of ornamental fitting, or in many cases suspended by a simple pendant, consisting of an insulated double flexible wire attached at its upper end to a ceiling rose, and carrying at the lower end a shade and socket in which the lamp is placed. Lamps thus hung head downwards are disadvantageously used because their end-on candle-power is not generally more than 60% of their maximum candle-power. In interior lighting one of the great objects to be attained is uniformity of illumination with avoidance of harsh shadows. ”

“ It must be remembered that electric lighting is comparatively a new science, and not yet fully understood. There is very little doubt that, by practice, it will before long approach more nearly to perfection, and sooner or later entirely supersede gas, the arc form of lamp being employed for the illumination of streets and large areas, while the incandescent pattern meets domestic requirements.—Good Words. ”

“ These glow-lamps are used for different purposes and ways. They may be used with care, they may be used recklessly; their duration depends a good deal upon the care with which they are used. A practiced eye, one who is accustomed to deal with electric lamps, can tell at a glance when the lamp is raised to a proper incandescence; but there is a point in all lamps that is a sign of danger, and indicates "breakers (or breakage) ahead." Whenever in an electric light installation a glow-lamp begins to show a blue effect, then breakers are ahead; the current must be reduced or other steps taken. ”

“ If the favor in which the electric light is held, and the great extent of its use, rested solely on the question of cheapness of production, such question would give rise to interesting debate. And, indeed, the debate would continue, if the question were the superior fitness of electric lighting for lighthouses and like service, where extreme brilliancy does not seem to penetrate a thick atmosphere as effectively as the more subdued glow of the oil lamp. ”

“ Now that the electric light has been made available for domestic purposes, and the very simple lamp (consisting of an exhausted glass globe, two platinum wires, and a piece of charred paper) can be obtained, people will no doubt soon largely adopt electric lighting in their houses. The light has found a success at the theatre, in the streets, and in the train; there is no reason why it should not be adopted generally, being more economical and more healthy than gas.
Fig. ”

“ Lamps not to be run too bright. For the sake of economy, it is well not to run the lamps too bright. Without giving the lamps the maximum current a very good light can be obtained, and they will last all the longer. I need hardly say that there is a medium in this as in everything else, and it does not look well when a candle is placed alongside of an electric lamp to enable a person to read or write in comfort.
All this time the dynamo is running, and we must feel the bearings occasionally to see if they [39] are keeping cool. No trouble with dynamo if oiling is attended to. ”

“ Find out the general period of the room and the color scheme so the lamp will be in keeping with the surroundings and provide the proper accent. Impress the customer with the necessity of a lamp for every grouping, and with the importance of good lighting.
Oil lamps for farm use have been styled to resemble electric lamps and have enameled bases, diffused reflectors and attractive shades. All lamps regardless of the source of light have been materially improved and there is no need for any person to have poor lighting in the home today. ”

“ We are standing today on the threshold of an entirely new era in lighting. New illuminants are being developed and new methods are being devised for applying light to meet the needs of modern living. Only a little over a third of a century has passed since the first incandescent lamp was invented by Thomas A. Edison, and the electrical industry has since made tremendous progress. ”

“ It is securely fastened to the table, which in its turn is fastened to the floor, and the light is supplied by a small incandescent lamp within the chimney, but concealed by the shade. The visitor never imagines that it is an electric lamp, and naturally thinks that it would be impossible for a kerosene lamp to be inverted without disaster, so that this adds to the deception materially. ”

“ It has been found by experience that the ordinary type of open arc lamp with vertical carbons included in an opalescent globe cannot compete in point of cost with modern improvements in gas lighting as a means of street illumination. The violet colour of the light and the sharp shadows, and particularly the non-illuminated area just beneath the lamp, are grave disadvantages. ”

“ No lamps should be allowed to stand about anywhere{203} and all must be out of the reach of the children, else will accidents certainly occur. The lamp must be re-trimmed and refilled daily downstairs by whoever attends to the sitting-room lamps, and must have a metal receiver. It must also be the reverse of cheap. Cheap lamps are dangerous and abominable in every way. Yet a lamp must we have in our nurseries if we wish the children to be well, and to escape the blighting influence of a gas-vitiated atmosphere. If no maid can be trusted to do the lamps the mistress must see to them herself. ”

“ The quality of light produced by an incandescent lamp is a gentler glow than that produced by the arc lamp, and in color more nearly resembles the light of gas or the oil lamp. The incandescent light speedily became for the home, hotel, hall, and limited covered area what the arc light became for the street and railway station, and, if anything, the former outstripped the latter in the extent and value of the industry it gave rise to. ”

“ If you want a really brilliant, clear, white light, you must trim the lamp yourself. A small piece of pale blue or neutral-tint glass, interposed between the lamp and the microscope, has a wonderful effect in diminishing the yellow hue which belongs more or less to all artificial lights which are produced by the combustion of oil or fat. We have no doubt but that in a few years we shall be rid of the clumsy and dirty machines that we call lamps, and have substituted for them the pure brilliancy of the electric light. ”