Gas burners to which gas-pipes lead are broadly classed in two divisions, one consisting of brackets or side lights, and the other of pendants i.vhich hang from a ceiling. In choosing a location for a bracket, care should be taken that it may not reach any movable article of an in flammable nature, such as curtains, cupboard or closet doors, etc. In the case of a pendant, the principal considerations relate to the strength of the connections by which it is supported, and to an avoidance of interference with the free movement of persons beneath it. The pipe to supply a bracket should be carried as directly as possible between the point in a wall from which it projects and the main supply, which may be in the ceil ing above or in the floor beneath or in the wall of an adjoining room or passage. Aside from the adjustment of the pipe which makes such con nections, special pains should be taken to insure reliable joints and to per fect the soldering and other necessary operations. In hanging- a pendant, the supplv-pipe is brought between the joists of the ceiling of the room to the desired point and appropriate connections are made, care being taken to secure proper provision for the strength of all the appliances used..
ilfadern InOrovements Gas great many designs of burners, chandeliers, pendants, brackets, and glasses for enclosing gaslights have been introduced froin time to time. Aside from the changes in orna mental effects which they represent, there are modifications which, it is claimed, possess economic significance. It is said that the old practice of making of metal the point of burners in contact with the flame, instead of some non-conducting substance, such as steatite, was radically defective, and that it necessarily led to a great waste of gas. Iinprovements in the construction of burners have also been found advantag-eous. It is found that the size of the burner should be proportionate to the quantity of g-as to be consumed, and that the gas should issue at a very low velocity. Respecting the use of glass globes, experiment has shown that perfectly plain and clean glass absorbs at least one-tenth of the light that passes through it, ground-glass absorbs one-third, and ordinary opal glass abstracts at least one-half, and generally more. Such globes should have au open ing- at the bottom at least 4 inches wide, through which the air can pass without disturbing the flame.
Electric rapid advances made during recent years in the application of electricity to practical purposes include a number of im provements which have a direct or indirect connection with building ope rations. They relate to the ringing- of door-bells or call-bells located in various portions of dwellings (fi/. 8, . 17), annunciators in hotels, etc.; to
lighting, heating, the signalling of fires, the detection of burglars; to fur nishing of power, methods of summoning police or messengers, telephonic communication, and various other purposes.
Electric of lighting interiors by electricity have been extensively introduced, especially in the United States, and appropri ate arrangements have been devised for conducting wires to the desired points in all parts of buildings. In connection with this subject, dangers have been developed against which ample precautions are provided; but neglect of these safeguards and careless workmanship have in some in stances led to deplorable accidents. The vital matter is the proper installa tion Of electric-lighting circuits.
As deaths also have occurred from accidental contact with poorly-insu lated electrical wires, all who participate in the introduction into buildings or the arrangement or repair of wires which are to be charged with electric currents should obtain and act in accordance with information that will insure safety.
Electric the protection of building,s from robbery, so-called burglar alarms, consisting of an alarm- or signal-bell set in opera tion by the making or breaking of an electric circuit by simple mechanism in connection with the doors and windows, etc., are in very general use. Another form of this class of appliances is a combined floor-mat and bur glar-alarm which is sufficiently ingenious to warrant a special description. It comprises an electric alarm-bell, a mat-carrving circuit, and closing and breaking devices, so that when the mat is subjected to pressure an alarm is sounded. The mat consists of narrow strips of wood connected to a fabric backing, and on the strip side of the mat is a series of springs which support the mat, there being two separate wires and the springs being securely connected to each wire. When the mat is stepped upon, the springs are compressed, contacts are made, and a current is sent through the connecting wires (which are embedded or grooved in the wood) to the bell electro-magnet, so as to sound an alarm. The bell has a switch or lever on the frame, by means of which, when moved, the vibrating ad justments are displaced, and the current ceases to flow through the anna ture spring or circuit break-er; it then passes directly through the macri -t c, , and upon the movement of this switch or side lever g-reatly lengthens the stroke of the armature, which is essential when a single stroke only is desired.