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.