This section is from the book "Modern Buildings, Their Planning, Construction And Equipment Vol3", by G. A. T. Middleton. Also available from Amazon: Modern Buildings.
Fire Risk. A properly carried out electric-light installation is considered by the fire offices to be safer than any other, but a badly wired building is much more dangerous from a fire point of view than one installed with leaky gas pipes. Of course, in the event of leakage only, gas is poisonous when compared with electricity. On the other hand, electricity practically always gives rise to heat at the point of leakage, and in this respect is more dangerous than gas. On the other hand, in case of leakage there is no controlling apparatus to automatically turn off the supply in case of gas, but the fuse, in a properly carried-out electric-light installation, will melt when a dangerous leakage of current takes place.
Fire due to contact with a burner is impossible with electricity, which is not the case with gas; while fires have been caused at the time of lighting the gas by the match or taper used for that purpose.
Health. It is somewhat a matter of opinion as to whether either illuminant has any deleterious effect, provided there be an ample supply of oxygen for the gas as well as for human consumption, together with an outlet for the products of combustion, such as carbon dioxide, traces of sulphur oxides, and moisture. Of these products carbon dioxide cannot be said to be healthy, although it is claimed that some of the sulphur oxides are health giving; but moisture is certainly not healthy. However, the worst of these products, carbon dioxide, is a heavy gas, and will therefore take its position about the floor, provided good ventilation does not remove it in its heated state. The most serious point to consider, therefore, is the consumption of oxygen, so that, provided there is good ventilation, gas could not be considered particularly unhealthy. On the score of health, nothing can be said against the electric incandescent lamp, and the only exception to a clean, bill for electricity in general is to be found in the special form of electric arc lamp called the "Flame lamp," in which coloured effects are obtained by impregnating the carbons with highly poisonous chemicals. These lamps should never be used for interior lighting.
The foregoing comparisons have been based upon the assumption that a public supply of either illuminant is available. It is therefore now necessary to briefly discuss the position of an isolated country house, institution, or factory which is presumed to be of a size not permitting the use of oil or tallow. Isolated gas plants are now rarely, if at all, used, for there are many disadvantages. In first cost the gas plant is more expensive than the electric light plant, as a considerable number of processes have to be gone through in order to produce gas from coal, while electricity is obtained by comparatively simple means. Owing to the small demand, there is a difficulty in the supply of the necessary skilled labour for the gas plant, and much more intimate knowledge of gas production is required than knowledge of electricity to run an electric-light plant. Proximity to a railway siding is more essential to the gas plant than to the electric plant, as a much greater amount of power may be obtained from liquid than solid fuel, though this point becomes equally divided when electricity is produced from a "power-gas" plant. It is necessary here to mention that power-gas plants do not require the skilled attention of illuminating gas producers, while their product is not fit for light.
As it is now possible to generate electricity at 1d. per unit, and with reasonable continuity, the electric-light plant should be given preference.
After carefully considering the advantages and disadvantages from the five most important points of view, it will be seen that electricity forms the best means for illumination, while for ordinary lighting gas is the cheaper.
Having considered the subject somewhat from the standpoint of the dwelling-house, it would be well to look into the position of the business premises, the theatre, and the public institution.
The business man will go deep into the cost per annum, and against this he will place the value of the character of the light from the advertisement point of view, and the ease and safety with which light is turned on and time saved in the operation. If he use gas his premises will need less heat but more ventilation. If, however, he has the space required for this purpose, and is prepared for the initial outlay, he will install the electric-light plant, provided that the amount of light he wants warrants this.
A theatre is obliged to use electricity, if only for stage effects. There are many almost inaccessible points where the electric lamp might almost be considered essential. Electricity gives light with minimum heat, and requires no oxygen from the air, while at the footlights it is much safer than gas. Lights may, too, be extinguished during the play instead of being turned down, as must gas, thus making for economy. In the theatre, of all places, it is essential to keep the decorations bright and clean. Gas must still be used as stand-by, but with this exception everything indicates electricity for the theatre.
Town halls and assembly rooms will follow the lead of the theatres, suitability, safety, and convenience weighing more than cost, while barracks, hospitals, and similar buildings could be lit by the cheaper light.