volume at high temperature. If a large air supply is wanted, its temperature must be low; and if the supply is small, its temperature must be high. Such a variable range of temperature requires special means for effecting it, either a dual system of supply by which hot and cold air can be mixed in such quantities as may be required for each room, or else a separate supplementary indirect heater for each room with by-pass arrangement.

Besides being somewhat cumbersome and expensive, these methods have still the failing that heating is dependent on ventilation to a greater or less extent. By the most efficient means heating can doubtless be done more cheaply by the direct than by the indirect method, since ventilation, by the very movement of warm air out of a building, carries heat with its discharge. Since during the session of the legislature, the committee rooms, the assembly balls, etc., are to be kept continuously warm, and need ventilation but one-half the time, and no ventilation except when the legislature is in session, and as their ventilation must vary with the number using them. I would recommend the distribution of air warmed only to seventy degrees or so to all rooms to be ventilated, and the placing of direct radiators within the rooms to furnish the supplementary heat required, the steam to be admitted to the radiators by such automatic means that the temperature of the room shall be kept at the desired point. Then, when the room is empty and the air supply small, or entirely shut off, the duty of heating will fall on the radiators; and when the room is crowded and the air supply large, the steam will be automatically shut off from the radiators.

All things considered, this is the most perfect arrangement I am able to suggest.

For the ventilation of the Hall of Representatives I would recommend that the supply of air be passed through the floor, and its slow diffusive movement into the room be effected through a large surface to be obtained by a special adaption of either the members' desks or the chairs to the purpose. The discharge I would effect through some suitable opening in the dome and by large outlets over the galleries and thence through the attic and dome and lantern.

Without further study of plans and conference with the architect, In general it any detailed statement of method is impossible. would include a fan in the basement with 1,000 square feet of steampipe heating surface, an air duct running along the ceiling through the corridor of the extension basement, with branches to

the flues in the corridor walls, and another air duct running to the basement corridor of the old building with large branches to the Senate and Representative halls, and smaller ducts to other rooms to be reached. The discharge would be by means of suitably sized flues in the corridor walls of the extension and by fire-place flues, and such other ducts as might be found necessary in the building, all ducts being properly carried up and terminated in the roof.

For extreme weather (-20° F.), for which the system must be provided, and when the system is doing full duty the coal combustion for warming the ventilating air will reach 250 pounds per hour, and the grate area provided for this purpose alone should be about 25 square feet. For heating the extension, aside from the ventilation of both the buildings, some 20 square feet of grate should be provided. This is found to be considerably more than double the present boiler power. The chimney should have a sectional area of 9 square feet for the total area of grate required.

The cost of using the proposed ventilating system to its full extent in mean winter weather would be from ten to fifteen tons of coal per month, or eighty tons if the system were so used continuously from the first of October to the last of May.

A rough estimate of the cost of fan, engine, steam heating surface, and return pumps to boiler, and large air pipes, for the vents of the entire building, is $2,200. For supplementary steam heating surface, vent pipes from top of wall and other flues to and through the roof, register faces, etc., $2075. For automatic electric apparatus for the control of steam to radiators, $1000. This does not include boilers and extra cost in refitting the Senate and Representative halls with new or altered desks, or chairs, etc.

If provision is to be made for the extension only, the estimate would be considerably reduced.

DOUBLE TUBE RADIATORS AND VENTILATION.

The use of these radiators, in connection with an exhaust method of discharge, removes none of the objections already mentioned as inhering in the vacuum method of ventilation. Its use as a means of supply is, in some important respects, faulty. Area of inlet, or quantity of supply, can be had only by correspondingly increasing the heating surface. For an audience room, small or great, such as committee or assembly rooms, the required inlet area can be had only by an accompanying excess of heating surface, and that where heating surface is least needed. In a crowded room, even in severe

weather, the heat of the audience is often more than sufficient to maintain a comfortable temperature, if the air supply is passed in at a temperature of only seventy degrees. But, under unusually favorable conditions, these radiators require two tubes per occupant for supplying air, and they are reported by their maker to so increase the temperature of the air flowing over them as to raise its temperature from sixty degrees to eighty degrees. In warmer weather-when more air is required at yet lower temperature than in cold-the supply through the tubes will be less in quantity and at a higher temperature. The larger the hourly air volume used, or the more rapid the change of air within a room, the lower must be its temperature, if it is the vehicle of heat also, and the warmer the outside air the less the temperature increment in the supply must be. The method of ventilation by double tube radiators seems therefore, faulty in principle and defective in the flexibility of its adaptation to the varied requirements a ventilating system is called on to meet.

Furthermore, the passing of air into rooms through wall apertures is not to be recommended, and for reasons among which are the following: Each aperture must have its valve to be opened and closed each day. Each of the thirty odd rooms in the extension would require for the purpose of ventilation, if not of heating, from one to three or more inlets, or the manipulation of from fifty to sixty dampers twice a day when all the rooms are in use. The almost inevitable tendency will be to a disuse of the dampers through the indifference of occupants and janitorial neglect, and the danger of exposure to freezing through either or both of these causes will be large and, perhaps, welcomed by a neglectful janitor as reasons for their permanent closing. The most serious objection to the use of wall apertures for supply is to be found however, in the disturbing, interfering and fitful action of the wind, forcing in excessive volumes of underheated air on the windward side, and not infrequently forcing out warm air on the leeward side, the system which is least disturbed by wind action is that of internal supply, and especially that whose motive power is independent of wind and weather.

Respectfully submitted,

S. H. WOODBRIDGE.

To His Excellency the Governor, HON. EDWIN C. BURLEIGH, Chairman of the Board of State House Commissioners, Augusta, Maine.

BOSTON, June 8, 1889.

A little later in June a special committee of the Commissioners, consisting of Hon. Lewis Barker and Hon. Henry Ingalls, accompanied by the Secretary of the State Board of Health, visited Boston and examined various systems of ventilation there employed. After a careful examination of the questions involved, this committee recommended to the full board of Commissioners, the adoption of such a system of ventilation as Prof. Woodbridge had already advised in a general way, and he was employed to draw up the full plans for this part of the work on the building.

CONTAGIOUS DISEASES.

The condition of the State as regards the prevalence of the infectious diseases, small-pox, diphtheria, scarlet fever and typhoid fever within the year has been very satisfactory indeed, with the exception of a very few towns, as may be gathered from a cursory examination of the reports of the local boards of health. In the following instances towns have been visited, on account of outbreaks of infectious diseases, by the Secretary or other members of the Board:

But one case of small-pox occurred, a case of varioloid at Readfield. Its origin was wholly unknown, though the patient, a young lady, had been to Portland in the cars ten or twelve days before the attack. She was isolated in her own home, the rest of the family were vaccinated, and there was no spread of the infection.

There has been a smaller number than usual of outbreaks of diphtheria, scarlet fever, and typhoid fever, uncontrolled and assuming alarming proportions. The Secretary went to Jonesport in July where diphtheria had been prevalent for some time. Considerable complaint had been made in the town, partly, that the local board of health did not do enough, and partly, that it did too much, meanwhile there was not so much disposition shown as there ought to have been, to put the shoulder to the wheel and help and encourage the Board, and the afflicted families.

In April, scarlet fever broke out among the students of the seminary at Kent's Hill, Readfield, and, unfortunately, the first cases were not isolated so promptly as they should have been. The result was an outbreak of moderate proportions which spread the disease to some other towns. In the fall another outbreak of the same disease occurred in the same institution and was confined to the first two cases by prompt and praiseworthy action on the part of the

local board of health and the school officers. Meanwhile the school continued its course without interruption.

In May, the Secretary was called to Winthrop on account of a small outbreak of scarlet fever. The disease was confined to a single family, But the father worked in the neighboring mill where many other persons worked, thus incurring the danger of spreading the infection broadcast. A talk was had with the man, and he agreed to remain isolated with his family. No new cases occurred until after the release from isolation when cases occurred in the family of a relative.

A small outbreak of typhoid fever occurred at Green's Landing, Deer Isle, due to bad water. The soil is thin and the wells as a general thing, go down to the underlying granite ledge and take their water from its surface, and as the privies and house drainage are, in many cases much too near, the conditions are extremely favorable for the soakage of polluting or infectious matter into the wells. A new water supply taken from outside the village is much needed.

Fairfield was visited by Dr. J. O. Webster, on account of typhoid fever in a tenement house, and another outbreak of the same disease in a similar institution, was seen by Dr. O. A. Horr. In both instances the outbreak seemned to be due to faulty sanitary arrange

ments.

INSPECTIONS OF SCHOOL-HOUSES.

NORTH SCHOOL-PORTLAND.

The city authorities, having made a praiseworthy attempt to remedy some of the evils connected with this building, described in the Third Annual Report, invited the members of the board to inspect their improvements on December 27, 1889,-but only Drs. Webster and Smith were able to be present. It was found that the schools were not in session at the time, so that no examination of the condition of the air was possible. The heating apparatus, however, was in operation, so that some measurements of the air supply could be made; but as the fires were only started that morning, it was thought that the results might not be equal to those ordinarily attainable, therefore Dr. Smith was requested to make further examinations, when the schools were in session. The improvements