At the Brussels Library the electric light has been applied to the reading-room where the periodicals are kept, and to the ante-room leading to it. In this latter, nine incandescent lamps (Müller-Nothomb's system) have been placed on brackets in groups of three. Three other lamps of the same system light up a passage leading to the machine. Finally, a soleil lamp with a globe completes the installation for the ante-room. The reading-room, with its semi-cylindrical ceiling, has been fitted up with three inverted soleil lamps (p. 300). These lamps, provided with opaque globes half hidden in flower-baskets, throw a diffused light on the ceiling, whose cylindrical surface disperses the light received, and thus illuminates even the remotest corners of the room. The titles of the books can be easily read on all the shelves, and the light hidden from direct view is soft, and possesses that pleasant tint characteristic of the soleil lamp.
The current is supplied by an alternating Gramme dynamo, which is driven by a locomotive engine. The machine feeds the four soleil lamps, as well as the twelve Müller-Nothomb lamps, which are joined for tension in the same circuit.
The Müller-Nothomb lamp, which is very little known in this country, differs from the other forms of incandescent lamps, not so much by the nature of the carbon filament, which is made of carbonized parchment, as by the way in which this filament is attached to the two platinum wires protruding into the lamp. The filaments are flattened out perpendicularly towards their ends, and attached to the platinum wires by a special cement. The lamp, instead of being completely exhausted, is filled with nitrogen gas.
One of the characteristic features of this lamp is the resistance it opposes to sudden changes of current; it only requires a current of two amperes, and is stated to give an intensity of from twenty-five to thirty candles.
From all the installations described above, it clearly follows that a mixed system of lighting has to be adopted for the individual requirements and special arrangements of different buildings. The number of these installations increases daily, but the electric light will only receive the general application it deserves when, by the establishment of central workshops, or by the reduction in price of storage batteries, electricity can be supplied cheaply, in any quantity and at any time. |
