At that time nearly everything was placed in pots of almost pure white sand, surrounded by the ordinary atmosphere of the house; while nowadays the establishment must be small indeed if it does not contain some place where the bed is so arranged that the heat at the bottom is from ten to fifteen degrees above that of the house proper. Here lies the whole secret as to whether it is a part of a single green-house or a house devoted exclusively to propagating purposes. For the purpose of being able at all times to control the temperature of the top, the propagating house has often a northern exposure, except in the very dead of winter. With a bright, clear sun above it is almost impossible in the daytime to keep down the temperature of the house sufficiently to prevent the young cuttings from wilting, after which disaster is very likely to follow in their final rooting. Given a top temperature never above 55 or 65 degrees, with a bottom always from 10 to 15 degrees higher, if the cuttings are in good shape it is a simple matter to root them in from seven to fifteen days; though the time it takes depends, of course, upon the plant and condition of the wood. At first efforts used to be contrived to get this bottom heat by means of the old flue system, with plenty of material covering the bricks, to break, in part, the dry burning nature of the heat. Then hot water came in and furnished what was thought the acme of a propagator, and tanks of elaborate workmanship, and made of the finest material down to the commonest wood, were made so a circulation of hot water was kept up over as large an area as the necessity of the owner might require. The results seemed excellent, but lo, every now and again, disastrous failures would occur. A material would spread all around called by the florist the cutting bench fungus, that would sweep through his crop like a plague; all sorts of theories would be given, and numberless articles appear in the horticultural periodicals of the day on its cause and cure. Presently it was found that those who did not use a tank of water, but had inclosed a space to be heated by hot water pipes, did not seem to suffer so much from the invidious foe. Much moisture was found an excellent remedy for the enemy, though it might have been its first cause, as it could be best warded off by dousing with the once praised hot water tank.