_Daylight._--Natural lighting is provided for by windows. The window area of a room should be well proportioned. In dwelling-rooms, it may amount to half the area of the external wall containing the windows; in churches, &c., ⅓ will suffice. Too great a window area is objectionable, as it considerably lowers the interior temperature in winter, unless very thick glass and double windows are provided. When windows become steamed or covered with condensed moisture in frosty weather, this can be cured by applying a very thin coat of glycerine on both sides of the glass. When direct daylight cannot be got, great advantage may be derived from using polished metallic reflectors. _Luminous Paints._--Several bodies possess the property of absorbing a certain amount of light and emitting it slowly. The most important of these is calcium sulphide. This property has been utilised by mixing the mineral with paint as a covering for surfaces where the light is required. The illumination, however, is very feeble. _Candles._--Candles will long retain a place in domestic lighting from their safety and convenience for carrying about. At the same time they are an expensive source of light, and not very powerful. It may here be mentioned that there is a right and a wrong way of blowing out a candle. If the candle is held on a level with the blower’s mouth, or blown down upon, as usual, as it stands on a shelf or table, the wick will smoulder and smoke till the room is filled with its disagreeable smell, and the wick burned away so that it can be lit next time with difficulty. If the candlestick is held well above the blower’s head, and the flame blown out from below, the ignited wick will almost immediately be extinguished, and no trouble will be found in re-lighting the candle. Avoid cheap candles; they burn rapidly to waste and play havoc with clothes and furniture by “dropping.” The best form of candlestick yet introduced is the “silver torch,” made by Wm. Nunn & Co., 204 St. George Street, London, E. By this the candle is converted into a lamp, with or without a globe as desired; the candle is completely consumed, leaving no ends, and guttering and dropping are quite prevented. Nightlights should always be burned under a glass shade, such as Clarke’s.