Frederick A. Draper
The greater safety attending the lighting of Christmas trees by electricity makes this method far preferable to that of the familiar candles, with the possibility of igniting the inflammable trees and decorations. By following the directions here given any one possessing ordinary skill can make and arrange the necessary fixtures to produce a very pleasing effect, and at a most reasonable expense.
The first consideration is the source of current; whether from the lighting circuit in a building lighted by electricity or, where such current is not available, by battery. The former will first be described, but before doing so it is well to mention that in some places the restrictions imposed by insurance authorities are very stringent and should be ascertained before commencing work, that the regulations may be properly complied with. Where battery current is used this trouble is avoided, as the current is of such low potential that no trouble would follow should short circuits occur, other than a quick exhausting of the battery and a failure to keep the lamps up the proper brilliancy.
Assuming that the current is to be taken from the wires of a regular incandescent lighting circuit, the voltage of which is between 108 and 112 volts, the first requisites are : Plugs for the sockets in which the lamps are affixed; enough two cord flexible wire to reach from the socket to the base of the tree; 100 feet or more of annunciation wire, divided equally between two colors to facilitate wiring ; the necessary number of 14 volt series miniature bulbs of 3 C. P. aud an equal number of porcelain sockets.
An examination of the tree having been made and the location and number of the lamps decided upon, a wiring diagram should be drawn showing the wires, lamps and connections, as it will probably be necessary to run the connecting wires from one branch to another to make up the complete circuits of eight lamps each. It will be noted that eight 14 volt lamps, "connected in series" make a total voltage of 112 volts, a slightly less voltage of the main circuit having but little effect on the several lamps. For each eight lamps on the tree, therefore, a separate plug and connecting wires will be required, unless one is sufficiently skilled in wiring to make a double connection and circuit through one plug, in which case other lamp on the same line circuit should not be turned on, to avoid overloading the line. All joints should be soldered and well insulated with electricians tape, except at the sockets, where a complete turn of the wire around the screw will answer, but at these points care should be exercised that the ends of wires are separated sufficiently to avoid short circuits. The lamps should be located in open spaces to secure the maximum effect and be visible to as large a portion of the room as possible, the general arrangement being that of a pyramid. A defective lamp will prevent the lighting of all and will have to be located and replaced with a good one when all will be illuminated. The number of lamps required will vary with the size of the tree; a small one requiring at least eight, and double the number can be used to advantage, and a large one is only limited by the time and money which may be available for the purpose. Colored bulbs add much to the effect; three red and three green for each ten white ones being a good proportion, the colored giving less light than the white ones. Directions for coloring bulbs were given in the January, 1903, number of this magazine, so will not be repeated here.
Where a commercial lighting circuit is not available and resort must be had to a battery current, the type of battery most suitable and easily constructed is that known as the bichromate plunge battery. The one described in the May, 1903, number, with an additional pair of plates, will be found satisfactory. The only alterations will be to lengthen the box 5 1/2 in. If made for only temporary use, exact work is not needed other than to make sure that the joints are perfectly tight. One battery as described will furnish ample current for about 24 1-C. P. 14 volt lamps connected in multiple on three separate circuits, the leads for each circuit being connected to the terminals of the battery which is connected in series, giving a full 14 volts. It will be necessary to have the windlass attachment so that as the current is continued the zinc plates may, at intervals, be lowered into the solution. At first the zincs should be lowered only sufficiently to bring the lamps to the full brilliancy, and there remain suspended until the lamps begin to dim slightly, when a little further lowering of the zincs will immediately bring them up again. On this ac-account it will be advisable to have the battery located under the tree, concealing it with paper or other decorations. The necessary supplies for all the fixtures, including thebattery can be ordered through any large electrical supply house, though it is probable that the battery parts will require a little time for filling the order and should, therefore, be ordered sufficiently in ad-vane of the time wanted to avoid disappointment.
Any one having difficulty in securing the supplies for the above work can, by communicating with the editor, obtain the names of firms from whom they may be ordered.