Nov. 1, 1881 | 855 | 3500 | |22 arc| 950 |2 40-Light to | | | .. |100 | 16 |“Brush” ma- Oct. 31, 1882| | | |Incan-| |chines. | | | |des- | |2 Fowler’s semi- | | | |cent. | |portable com- | | | | | |pound engines 20 | | | | | |HP nominal. -------------+--------+------+-------+------+--------+---------------- As to the comparison of cost between the electric light and gas, this has only, I believe, been properly estimated on the Thames Embankment, London, by Sir Joseph Bazalgette, the results of whose investigations upon this important point I shall give presently; it has, however, been stated generally, and without contradiction, that arc lights can be produced of about 2000 candle power, with 1 HP at a cost of from 3_d._ to 6_d._ per candle per annum of 4000 hours, gas costing from 1_s._ 9_d._ to 3_s._ 6_d._ per candle according to the price of the gas. Incandescent lamps cost 3_s._ to 4_s._ per candle per annum, as their life is short, and only 200 candle power can be got from 1 HP.[121] The latest investigations into the comparative cost of lighting by gas and electricity upon the Victoria Embankment and Waterloo Bridge in London, show that the lighting as effected by 96 gas burners for an average of 12 hours burning all night, and 121 gas burners for 6 hours lighted after the electric lights are put out, together with the electric lighting 40 lights on the parapet of Embankment, and 10 on the bridge, costs 834_l._ for the gas and 663_l._ for the electric light per annum. Gas costing 3_s._ 2_d._ per 1000 cubic feet showed a cost of nearly 1_s._ per hour for every 1000 candle power of light. The electric lights cost 1¹⁄₂_d._ per light per hour, which is stated to represent 5·66 pence per 1000 candle power of light; each electric light as now used, it is said, gives a photometric light of 265 candles, frosted glass globes being found to pass much more light than the opalescent globes. These are by far the most important and reliable comparisons that have hitherto been made, and it will be seen that the cost is in favour of the electric light. There is no doubt that the acme of all artificial lighting is the prolongation of the light of day, and whether this is proposed to be effected by electricity or gas, it should be the goal aimed at by all who make this question their study. [112] Since writing these lines the following letter has appeared in the Standard and has never been refuted, which shows that electric lighting for streets is not yet all that can be desired: ELECTRIC LIGHTING. _To the Editor of the_ STANDARD.