traps should run out of the building as quickly as possible, and be easily accessible for inspection at all times. It is well to paint their outer surface white, as any leak or escape of gas quickly causes discoloration, and is at once detected.

The utmost care should be taken in the ventilation of the traps, pipes, and drains, as, however costly the fixtures may be, unless they are properly ventilated they will be objectionable.

As no public drainage is likely to exist, a cesspool will probably have to be used for the reception of sewerage. Let this be as far as possible removed from the building, and placed in some remote, unfrequented corner of the lot. By all means use a tight cesspool, and do not on any condition use the leeching cesspool, as it is impossible to tell what course may be taken underground by the filth discharged from it. Pollution of well or spring water at long distances has often been traced to this cause, while hundreds of undiscovered cases now exist. A tight receptacle of ample size, thoroughly built and properly ventilated, will not be obnoxious, and can be pumped out once or twice a year at a small expense. It would be useless to attempt a system of sub-irrigation for a single building of small size, for while this disposal of liquid waste has much to recommend it when planned upon an extensive scale, I do not consider that it can be practically applied upon a single building without a very large expenditure of money.

HEATING AND VENTILATION.

Under this head will be found the true test of the successful hygienic construction of a building. To heat any room to a required temperature in the coldest weather is a very simple matter. To bring into the room a sufficient supply of pure, warm air, to remove the vitiated air, maintaining at all times and in all parts of the room a steady circulation or mixing of the air without causing unpleasant draughts, is a far more difficult thing to do. That it can be satisfactorily done is only a question of understandingly applying the means that are at hand.

In the smaller rooms and the halls of the accompanying plans I would use direct steam. In the main school-room the indirect system will be far better.

Before going into the details of the heating apparatus, it would

be well to consider briefly the requirements of the school-room, the quantity of air that it is necessary to supply, the capacity and position of the incoming and outgoing registers, and the general laws governing the movements of air.

The school-rooms that I show on the accompanying plans contain about 16,128 cubic feet of air, an average of 347 cubic feet per person. I believe in supplying to each occupant as near 30 cubic feet of pure warmed air per minute as possible. To do this, we shall be obliged to bring into the room every hour 1,800 cubic feet per person, or a grand total of 88,200 cubic feet. Of course, if this amount is brought in, proper provision must be made for its removal as soon as it has become vitiated, which will cause the displacement of all the air in the room 5 times each hour, or once in about eleven minutes. Some may consider the quantities I have named in excess of the actual requirements, and that it is not possible to introduce and move such quantities of air, unless a gigantic apparatus is used and an enormous amount of fuel consumed. In answer to the first objection, I would say, that the highest medical authorities insist upon about the same amount as a standard;-and to the latter, if the apparatus is properly constructed, and understandingly handled, no unnecessary expense will be incurred.

There is much diversity of opinion among experts as to the position of incoming and outgoing registers. Many advocate placing the incoming registers in the floor, some on the side walls near the floor, and a few high up on the side walls. The latter is the only proper place for them, and it seems to me the worst kind of bigotry, with our knowledge of the action of warmed and cooled air, to insist that the floor is the best place. We all know that warm, pure air is light, and will rise rapidly to the top of the room, no matter at what point it is introduced. It is an equally well established fact, that foul air is heavy and settles in the lower part of the room. I cannot understand why, with these facts before them, it is still sometimes argued that the floor is the best place for registers. If you introduce the pure, warmed air there, you are bound by natural laws to carry it through a stratum of impure air before it reaches the top of the room; and I think no one will have the hardihood to claim that it has passed through the impure stratum without becoming contaminated.