workman, who a few days later reported that now all the bells rang at once, and he had had to disconnect the battery! He produced a sketch of the connections he had made, and on his error being pointed out he was able to rectify it, and the bells answered to touch without the use of the extra cell. Generally speaking, a failure on the part of electric bells is corrected by filling up the cells which compose the battery with water, an operation which any one may undertake. It is not safe, however, for an inexperienced person to interfere with electric light fittings further than to remove a worn-out lamp and place a new one in the socket, and even this operation may be attended with disaster. A young friend of ours who was taking part in some private theatricals obtained the loan of a row of electric footlights. It did not occur to any one concerned to ask the voltage of the lamps or of the current to which they were to be applied. When the footlights were turned up they blazed for a brief period, and then every light in the house went out! Electrical science for the housewife has been resolved into a knowledge of electric terms and of a few practical rules useful and interesting in themselves, but not immediately suitable for our purpose of showing how scientific study may aid the housewife in her daily routine. PHYSICAL SCIENCE IN THE HOUSEHOLD We may for this purpose examine some of the laws of common physical and chemical phenomena, neglect of which has resulted in much needless discomfort in daily life, and even more serious consequences. For instance, the laws of expansion of gases and liquids with heat, and their subsequent behaviour, are phenomena that are often imperfectly realised. There is probably no person who is unacquainted with the law of gravitation, but there are many persons who accept literally the statements that smoke rises and that balloons ascend. A clear understanding of what actually takes place when gases and material masses appear to move in opposition to the law of gravitation is essential to any scheme for warming and ventilating the house.