WARMING AND VENTILATING OCCUPIED BUILDINGS. 305 



happened at Lariboisiere Hospital have even shown that this system is 

 not entirely free from sudden ruptures. 



The advantages of steam-heating may be retained, without its prin- 

 cipal defects, by arranging the circulating-pipes vertically in shafts 

 formed in the thickness of the walls, or specially built for them, as 

 has been done in some wards of the Viucennes Hospital, or as d'Hame- 

 lincourt has arranged it for the circulation of water at the company's 

 office at the Northern Eailway. 



Some of these pipes may be exposed in the form of columns, and be 

 used for warming the hands or the feet, as is done in many establish- 

 ments in Germany and Switzerland. 



These arrangements, which agree very well with the condition that 

 the fresh air should enter near the ceiling, secure the immediate return 

 of the condensed water to the boiler, and, therefore, greatly diminish 

 the effect of leaks, which would be more easily prevented than in the 

 forms usually adopted at present. 



l!^othing should prevent the adoption, in each ward (ff a hospital, of 

 an evaporator warmed by steam on Grouvelle's system, in order to pro- 

 mote the comfort of the patients. 



It is proper to add that when the radiators and pipes have a heating- 

 surface of 215 to 258 square feet for 35,316 cubic feet capacity of halls, 

 an elevation of temperature of 29'^ or 32"=^ may be obtained even in the 

 coldest weather. At Lariboisiere Hospital the proportion is 280 square 

 feet, and it is evidently greater than necessary. But there remains 

 against steam-heating the charge of being too readily affected by irreg- 

 ularities in the fire, and particularly by want of attention on the part 

 of the firemen, which during the night may- be very much prolonged. 



HOT-WATEE, HEATING-APPARATUS. 



25. This system of warming, which has been known and in use for a 

 long time with various modifications, is much less apt to cause sudden 

 variations of teu-perature than the preceding, since hot-water vessels 

 and pipes of equal capacity always contain a much greater number of 

 units of heat than if filled with steam. The great density of water and 

 its steady circulation through the heater long after the fire has become 

 low, maintain a very regular heat in spite of temporary want of atten- 

 tion. 



The temperature of the air warmed by this apparatus is always 

 very moderate. It is even difficult to raise it above 100° or 112° with 

 large radiating-surfaces. In this respect this method of heating is very 

 healthful, provided that ample ventilation be maintained in addition. 



It is not essential to follow L. Duvoir's plan of placing regulating- 

 receivers in the upper part of the house to which the warm water 

 ascends, in order to secure a sufficiently rapid circulation by the differ- 

 ence in the density of the high ascending and descending columns. 

 20 s 



