When the priming of a canvas has become detached, or the cloth is so old as to need sustaining, it is customary to line the picture. - But if the canvas is greatly injured, the painting itself is transferred to a new subjectile. In order to render the old canvas and the color softer and more manageable, expose the picture for several days to damp. When all is ready, the first step is to fasten, by a thin flour-paste, white paper over the whole painted side of the picture, to prevent the colors scaling off. Having a new canvas duly stretched on a strong frame; a uniform coat of well-boiled paste, made of rye-flour with a clove of garlic, is spread nicely over it by means of a large brush. With despatch, yet care, a coat of the same paste is spread likewise on the back of the picture. - The latter is then laid upon the new cloth, the two pasted sides, of course, together. With a ball of linen the usual rubbing is given with a strong hand, begining at the centre, and passing to the edges, which must be carefully kept in place the while. In this way, the air is expelled, which remaining would cause blisters.

The picture thus lined is then placed upon a smooth table, the painted side down, and the back of the new canvas is rubbed over boldly with any suitable smooth-ing-instrument, such as is used for linen, paper, or the like; and a warm iron is then passed over the picture, having on the other side a board to resist the pressure. The paste being heated by this iron, penetrates on the side of the picture, and fixes still more firmly the painting, while on the other side the redundant part of the paste escapes through the tissue of the new cloth, so that there remains everywhere an equal thickness. The iron must not be too hot, and before applying it, several sheets of paper shoud be interposed between it and the paper that was at first pasted on the painting, and which would not be sufficient.

When the lined picture is sufficiently dry, the paper last mentioned is damped, by passing over it a sponge moistened with tepid water. It soon detaches, and with it is removed the paste that secured it to the picture. All that remains is to clean the painting, and where needed to restore it.

The above operation will not, of course, be attempted by the amateur, except for experiment upon some picture of little worth; for even practised hands frequently injure what they were employed to preserve.