for the night. No provision was made for exclusion on account of illiteracy or in case of physical disability. So far as hours of labor was concerned it put boys upon the same level as men.

With the exception of education this, I am pleased to say, has all been put right. The day cannot now begin before 6 in the morning nor end later than 9 at night. Boys under 18 years of age are not now permitted to work more than ten hours a day or sixty hours a week. Boys, girls and women whom the inspector may consider physically unfit for their work, may now be excluded unless a medical certificate is produced testifying to the contrary.

I am sorry to have to admit to the members of this convention that we have not a free and compulsory system of education in our Province. The subject is, however, attracting the attention and support of all good men and is being much agitated by the press. My own impression is that we shall soon arrive at a solution of the question, so that the educational standard of our boys and girls will not be below that of our sister Province, Ontario; as it is at present by from 10 to 15 per cent., according to the census.

The act of 1885 provided for the fencing of dangerous places and moving parts of machinery. These matters have since been amplified and more clearly specified by regulation.

Regarding fire-escapes, amendments have been made giving the inspector the right of specifying as to material, size and form; also the right of deciding where they should be placed. The owner, lessee and occupant have been made jointly and severally responsible for their erection.

By an addition to the law all steam boilers are to be inspected once a year by a certified inspector, whose duty it is to report to the factory inspector. This department has not run as smoothly as it might, owing, I think, to the system of paying the inspector by fees instead of a salary; still the work has been done satisfactorily, which was the main object in advising the legislation. A sanitary physician was added to the staff some years ago, who is at the disposal of the inspector in case of need.

The Quebec factories act of 1885 was repealed in 1894. At the same time the Quebec industrial establishments act was proclaimed. It embodies all the amendments that I have mentioned; but in other respects it differs little, except in phraseology, from the old statutes. Under it, however, elaborate regulations have been adopted by the Lieutenant-Governor in Council, providing explicitly for safety against unguarded machinery, hoists, shafting, gearing, belting, etc., and, in fact, almost everything that might be a means of injuring the person; means of rendering escape from fire easy are also provided. To be candid, I believe that some of the clauses are too rigid and impracticable. It is better to do well that which is practicable than to strive for the impossible.

The public buildings act of 1894 was put into force during that year, so that we are now inspectors under two different acts. This, of necessity, has increased our work.

All our notices, forms and papers are printed in French and English. Verbal or written communications can be made in either language.

I said at the beginning that three inspectors were appointed when the act was put in force in 1888; at present there are five male inspectors, of whom one is chief; a sanitary physician and two female inspectors. The female inspectors. were appointed on the 1st of July, 1896, so that their usefulness has not yet been practically demonstrated. I well remember, when the female inspectors from the States of Pennsylvania and New York attended the convention at New York in 1890, that the male inspectors were not very sanguine as to the success of inspection by females. I am told that the movement has proven successful, which goes to prove that men make mistakes sometimes.

Before closing I must express my thankfulness to the inspectors from the United States and from Ontario for their courtesy in sending their reports and other information to our office. Although we have not reciprocated as we should, we promise to do better in future.

As regards our attendance at the convention, I am sure it is a pleasure for Mr. Guyon and myself to be with you. We are fully alive to the importance of such gatherings as this, from an educational point of view, and I can assure you, ladies and gentlemen, that our present Prime Minister is in full sympathy with this or any other movement that will improve his officers and enable them to discharge their duties with credit to themselves and benefit to those concerned. The next paper, read by Mr. John T. White of Massachusetts, was concluded at 10 P. M., when the convention adjourned. Mr. White's paper was as follows:

VENTILATION.

Mr. President and Members of the Convention: The subject of the paper assigned to me to read to you to-day is "Ventilation." I shall not take up your time by any discussion of theories. Exhaustive treatises on the subject of ventilation can be had at any book store, and are to be found on the shelves of nearly every public library. I shall devote this paper mainly to an effort to present a few facts regarding the practical application of the theories of ventilation in the schools of Massachusetts, as obtained in the work of the State inspectors of public buildings.

Nearly every work on ventilation that I have ever read begins with a statement of the chemical composition of the atmosphere. We are told, to a small fraction, the percentages of oxygen, nitrogen and carbonic acid contained in pure outside air, as well as the amount of watery vapor necessary, or supposed to be necessary, for the best conditions of health. It is well enough to know all these things, but as such information can be readily had in any encyclopedia or elementary work on chemistry, I shall treat this side of the subject very briefly in this paper, and make it as free as possible from technical terms.

Suppose we have a school-room containing exactly ten thousand cubic feet of air space and filled only with pure outside air. In such a room we should have somewhat less than eight thousand cubic feet of nitrogen gas, a little more than two thousand cubic feet of oxygen and about four cubic feet of carbonic acid gas, or carbon dioxide.

The only constituent of the air that we need to notice is this small percentage of carbonic acid. If the air contained more or less of any of these gases, the mechanics of ventilation would be unchanged; but the amount of carbonic acid gas is of importance to us for the reason that as the air of a room grows foul from exhalations from the lungs and persons of its occupants, the amount of this gas increases in nearly exact proportion to that of certain other and more injurious impurities. Now, while these other impurities are very difficult to measure, the percentage of carbon dioxide is easily determined. Therefore, we speak of the air of an occupied school-room as containing a certain amount of carbonic acid, because the amount of that gas is an index of the degree of vitiation of the air.

Let us now suppose that into our room containing ten thousand feet of pure air, there enter fifty persons, and that each one of these persons will exhale sixtenths (0.6) of a cubic foot of carbonic acid per hour. Then, at the end of one hour, if the room were tightly closed, we should have the initial amount of this gas, plus thirty feet produced, or thirty-four cubic feet of carbonic acid gas in the

room.

Let us during this time slowly admit ten thousana cubic feet of pure air to the room, allowing, of course, an equal amount of vitiated air to escape. Of the four cubic feet of carbonic acid in the room, plus thirty feet produced, plus four feet in the admitted air, or thirty-eight feet in all, one-half would have been removed with the air allowed to escape, leaving, if the ventilation has been perfectly efficient, nineteen cubic feet of carbonic acid in the room at the end of the hour.

If, instead of supplying ten thousand cubic feet of fresh air and changing the air in the room only once in the hour, we should supply and remove thirty thousand cubic feet, we would, of course, still further dilute the carbonic acid. By supplying and removing a much larger amount of air per hour, we could reduce the amount of carbonic acid to eight cubic feet. This amount, eight one hundredths of one per cent., or, as usually expressed, 8 parts in 10,000, is generally considered to indicate fairly good ventilation.

Authorities differ

In a recent work on ventilation, Prof. Carpenter says: greatly as to the amount of air to be provided per person, but, at the present time, they seem well united in considering the admission of thirty cubic feet per minute for each person, as giving good ventilation." He then goes on to say that "this amount is required by law for school buildings in Massachusetts."

This latter statement is not quite correct. The law in Massachusetts does not specify any amount of air to be furnished in school-houses or other buildings. The requirement of thirty cubic feet per minute per person is one of the regulations of the State Department for the Inspection of Buildings, and was based on what the observations of the inspectors had shown could be easily furnished by gravity systems of ventilation. It is a rather low standard, especially for steamheated buildings, and it is now being very considerably exceeded in the average of good work. It is probably, however, very near the limit of the amount of air which can be properly heated and distributed by hot-air furnaces, where two rooms are heated by one furnace.

Perhaps it may be of interest here to quote the regulations referred to, as approved by Chief Wade. They are as follows:

In the ventilation of school buildings the many hundred examinations made by the inspectors of this department have shown that the following requirements can be easily complied with:

1. That the apparatus will, with proper management, heat all the rooms, including the corridors, to 70 degrees F. in any weather.

2. That, with the rooms at 70 degrees and a difference of not less than 40 degrees between the temperature of the outside air and that of the air entering the room at the warm-air inlet, the apparatus will supply at least thirty cubic feet of air per minute for each scholar accommodated in the rooms.

3. That such supply of air will so circulate in the rooms that no uncomfortable draught will be felt, and that the difference in temperature between any two points on the breathing plane in the occupied portion of a room will not exceed 3 degrees.

4. That vitiated air in amount equal to the supply from the inlets will be removed through the ventiducts.

5. That the sanitary appliances will be so ventilated that no odors therefrom will be perceived in any portion of the building.

To secure the approval of this department of plans showing methods or systems of heating and ventilation the above requirements must be guaranteed in the specifications accompanying the plans.

It is with the physical properties of air rather than with its chemical composition that the ventilating engineer has to deal. It is a property of air that it expands about one five-hundredth part of its volume at 32 degrees for each degree of increase in temperature. If, then, we take 100 cubic feet of air at 32 degrees F. and raise its temperature 50 degrees we shall have about 110 cubic feet at 82 degrees.

This heated air, being lighter than the surrounding air at 32 degrees, tends to rise by the same law by which a cork rises from the bottom of a vessel of water. To this property of air we owe all ventilation, natural or artificial. The air at the surface of the earth, heated and expanded by the rays of the sun, rises to upper regions and the cooler air comes in to fill the partially unoccupied space. In this way our whole atmosphere is kept in constant circulation and of an even degree of purity.

It is upon this same principle that all our work in the ventilation of occupied apartments is accomplished. When the weather is warm enough for us to open our doors and windows we may let nature do our ventilating for us, but when the weather is so cold that we have to warm our rooms we have the problem of artificial ventilation before us.

Under such circumstances we have a choice of two methods of keeping our apartments comfortably warm.

We can warm the air before we admit it to the room in any of the ways in which such work is done or we can keep ourselves warm by means of stoves or steam or hot-water pipes within the room. The latter method is the cheaper, but it furnishes no ventilation except what we may obtain by leakage or diffusion of air through the walls of the apartment.

Fortunately our houses are not so constructed as to be impervious to air. There are small openings all around the doors and windows and the walls of the

building are more or less porous. The air that is heated by stoves or steam pipes is constantly rising to the ceiling and passing out through every pore and crevice in the upper portion of the room, and outside pure air is coming in by the openings below. It is to this method of air supply that we owe the fact that we do not suffer more from foul air in our dwellings.

It has been found that by diffusion through the walls of a room the air within can be changed about once in every hour when the difference in temperature between the inner and outer air is 34 degrees F. But such diffusion is very uncertain and should not be taken into account in providing means for ventilation, especially in our modern and better constructed buildings.

People who remember the school-houses of fifty years ago frequently remark that there was no trouble about ventilation in those days, and they wonder why the children of to-day need so much more air than their fathers had when they went to school. A very common plan of a school-house at that time was to have a passage leading from the front door to the teacher's desk at the other end of the room, with a wood-burning stove about half-way in the length of the passage. The seats rose on each side towards the cold. lighted walls. The heat from the stove caused an upward movement of air in the middle of the room and there was a lateral movement over the scholars from the cold walls and windows, and as the buildings were generally very loosely constructed considerable ventilation was furnished in this way. The great trouble was that the children on the back seats were freezing while those near the stove were uncomfortably warm. By tests recently made in some of these old buildings still in use there was found to be a difference of 48 degrees between points five inches above the floor and points five feet above it in occupied portions of the rooms, and of 17 degrees between points on the same level. Compare these figures with the requirements of form No. 83, before given, and you will perceive that there has been a great improvement in the comfortable heating of school-rooms as well as in ventilation.

The Massachusetts law requiring school-houses and other public buildings to be properly ventilated was enacted in 1888, and as re-enacted in 1894 (Chapter 508 of the acts of that year) reads as follows:

Sec. 40. Every public building and every school-house shall be kept in a cleanly state and free from effluvia arising from any drain, privy or other nuisance, and shall be provided with a sufficient number of proper water closets, earth closets or privies for the reasonable use of the persons admitted to such public building or of the pupils attending such school-house.

Sec. 41. Every public building and every school-house shall be ventilated in such a proper manner that the air shall not become so exhausted as to be injuri. ous to the health of the persons present therein. The provisions of this section and the preceding section shall be enforced by the inspection department of the district police.

Sec. 42. Whenever it appears to an inspector of factories and public buildings that further or different sanitary provisions or means of ventilation are required in any public building or school-house, in order to conform to the requirements of this act, and that the same can be provided without incurring unreasonable expense, such inspector may issue a written order to the proper person or authority direct