A Fire Screen.
Draw a landscape on paper with common Indian ink, representing a winter scene, a mere outline, the foliage to be painted with muriate of cobalt (green), muriate of copper (yellow), and acetate of cobalt (blue), all which colours are invisible; but on the screen being held near the fire, the gentle warmth will occasion the trees, flowers, &c. to display themselves in their natural colours, and winter is magically changed to summer. As the paper cools, the colours disappear, and the effect may be repeated as often as required.