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 L426 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 L994. 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--

L 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.......... L109 10

leaving a handsome balance to the good of L316 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