WARMING AND VENTILATION. 317 



It would then have been necessary to admit into and withdraw from 



the room every hour the enormous amount of — 



170(501*2 

 ' .^.. = 2,703,000 cubic feet of air, 



or 751 cubic feet a second, which corresponds to a complete renewal of 

 the air of the room effected — 



2703000 ,„.^ ^. , 



.^■■.. ■■ ■ = 13.o2 times an hour. 



By means of chimneys extending to the roof, a velocity of discharge 

 equal to at least 7 feet a second could have been obtained, and their 

 sectional area and that of the openings into them would have to be 114 

 square feet. Supposing five of the latter to be placed in the ceiling, 

 each would require to be 23 square feet in area. 



However great the amount of air to be removed and the areas of flues 

 may seem, there need be no serious difficulty in obtaining them. 



115. Throne-room. — This room has the following dimensions: length, 

 94 feet; breadth, '60 feet; height, 20 feet; cubical capacity, 88,000 cubic 

 feet; floor-surface, 3,380 square feet. It accommodates 95 guests at a 

 table 77 feet long by ]3 feet wide, having, therefore, a circumference of 

 180 feet, which gives each guest but 1.9 feet of space. 



The number of servants is about 25, There are then 120 persons in 

 the room. 



The cubical space to each person is — 



88000 noo r- f ^ 

 -YTwj- = 733 cubic feet. 



The floor surface to each person is — 



3380 



-TTjTT = 28 square feet. 



Under these circumstances, it is lighted up by — 



12 chandeliers of 96 candles 1,152 



4 candelabra of 25 candles 100 



On the table 370 



Total 1,022 



or, 17 candles to a guest. 



Allowing, as before, that a candle gives out 47G units of heat an hour, 

 the same as a person, the total number of units of heat given out an 

 hour would be — 



(120+1022) X 470 = 829, 192 units. 



Supposing that the air had been introduced at a height of 20 feet, and 

 at a temperature of 59°, and that this air, after having become heated 

 to 95°, had escaped through openings in the ceiling, every cubic foot of 

 air introduced would have carried away, as in the preceding case, .6536 

 unit. 



