£ s. d. Carbons............................... 18 9 0 Oil, etc.............................. 4 11 6 Coal.................................. 11 14 0 Wages................................. 34 7 6 ---------- £69 2 0 being at the rate of 3s. 10d. per hour of light. Now, the consumption of gas in the court would have been 4,800 cubic feet per hour, which, at 3s. 4d. per 1,000 cubic feet, would amount to 16s. per hour, thus showing a saving of working expenses of 12s. 2d. per hour, or, since the museum is lit up for 700 hours every year, a total saving at the rate of £426 per annum. In estimating the cost as applied to this court, only half the cost of the engine should be taken, for a second dynamo machine has lately been added to light up some of the picture galleries, and the "Life" room of the Art School. The capital outlay should, therefore, be £994. In making a fair estimate of the annual cost, we should also allow something for percentage on capital, and something for wear and tear. Take-- £ s. 5 per cent, on the capital............................. 49 10 5 per cent, for wear and tear of electrical apparatus.. 39 0 5 per cent, for depreciation of engines, etc........... 21 0 ------- Total.......... £109 10 leaving a handsome balance to the good of £316 10s. as against gas. The results of the working, both practically and financially, have proved to be, at South Kensington, a decided success. I am indebted to Colonel Festing, R.E., who has charge of the lighting, for these details. The same comparison cannot be made at the British Museum, for no gas was used in the reading-room before the introduction of the electric light, but the cost of lighting has proved to be 5s. 6d. per hour--at least one-third of that which would be required for gas. The system in use at the Museum is Siemens', the engine being by Wallis and Steevens, of Basingstoke.