One Thousand Ways to Make Money by Page Fox

865. GLASS BRICK.--Another new idea! Why not make a brick of glass,

partially hollow, so that, filled with rarefied air, it can be a non-conductor of heat? Such a brick would be a great improvement on the present method of constructing conservatories, greenhouses and the walls of winter gardens. The plan is being tried in Europe, but there is no patent on the introduction, and nothing to stop an American from introducing a new kind of hothouse. The adage about the “man in a glass house” may be realized yet.