I 



WARMING AND VENTILATION. 297 



pensive to place hot- water receivers in the form of a drum, or of pipes 

 such as are oTteu used in heaters, into which hot-water pipes should be 

 tapped, and then carried vertically in the foul-air flue leading from the 

 rooms, thus securing a change of air at all times and without expense. 

 In this way, also, baths might be supplied, which would be of great 

 service for soldiers' hospitals. Ventilation being, as has been said, much 

 more important at night, when all the men of one mess are together, 

 than during the day, when most of them are out of doors, the registers 

 — the regulation of which should only be made by the order and under 

 the direction of the adjutant of the week — will serve to cheek or prevent 

 escape of air during the day, so as to accumulate heat in the flues for 

 the night. 



HOSPITALS. 



82. General plans and dimensions to he adopted for the ventilation of 

 Jiospitals. — It is only j)roposed in what follows to give the propor- 

 tions of the principal parts of the flues and pipes which it is necessary 

 to use for the ventilation of hospital-wards, in order to secure the re- 

 moval of vitiated air and the introduction of fresh air. 



These proportions apply also to the difl'erent plans which local condi- 

 tions may cause the architect to adopt. 



The amount of air to be renewed in the sick-rooms may vary, accord- 

 ing to circumstances, from 2,000 to more than .3,500 cubic feet an hour 

 for each bed ; 2,800 will here be taken as a basis for the calculations. 



. When local conditions permit, the foul air should be drawn off through 

 descending passages ; openings into them being made behind the head 

 of the beds, at the floor-level, but in the vertical walls, to be in number 

 at least equal to one for every two beds in ordinary hospitals, and one 

 to each bed in lying-in hospitals. 



When a hot-water heating-apparatus is used, and when the plans 

 adopted as well as the proximity of chimneys permit, the waste heat 

 from the small heaters and hot-water tanks used in the hospital should 

 be made use of to assist the draught. 



But it is not necessary that the use of these little reservoirs, which 

 have but a small capacity, should lead to the exclusive adoption of the 

 up-cost draught, as L. Duvoir has done, and which is less advantageous. 



83. Advantages of the doicn-cast dravght. — It will be remembered that 

 the arrangements required by the down-cast draught lessen very much 

 the weakening of the walls by the passage of ventilating-flues. 



Thus, for a building with rooms on three floors, as in the case of Lari- 

 boisiere Hospital, the piers of the third story are not pierced for any 

 flue, because their own commences at the floor ; those of the second 

 story are only pierced by a single flue coming from the third floor; and 

 those of the ground-floor only contain the two flues belonging to the 

 second and third stories. 



The thickness of the walls being greater at the lower stories, the flues 

 "would always be proportionally less injurious with descending draughts 



