Concealed lights are not so much in use as they might be. The effect of 'a moon unseen albeit at full' may often be obtained for some faint-coloured picture, hardly visible when a glaring lamp is held between it and the eye, by a concealed lamp with the right kind of shade. Luminous points, silvery, murky, rosy, are often wanted for certain effects, little surprises behind screens or in side-niches which seem fairly magical when the source is hidden, and changes of white light for tinted light are often very beautiful.

However, when the electric light comes into common use, the problem how to light adequately a large room without heating it will be solved. I have seen the picture gallery at the Fitzwilliam Museum, at Cambridge, successfully lighted by electricity subdued by a tinted globe; Lord Salisbury has introduced it at Hatfield; but a revolution in dress-colours and wall-colours will doubtless follow its introduction in private houses, for some of our now fashionable colours, specially intended for use by the yellow light of gas, are greatly altered under the electric rays; and the complexion itself suffers at present. Blues and peacock-greens become painfully vivid; while yellow, which nearly disappears under gas, keeps its natural colour.