316 WARMING AND VENTILATION. 



As examples, chosen among those which apparently offer the greatest 

 difficulties, I select the diuing-rooms of the Hotel de Ville, Paris. 



114. State dining-room. — This immense room has the following dimen- 

 sions: length, 150 feet; breadth, 34 feet; height, 38 feet ; cubical con- 

 tent, 200,000 cubic feet ; floor-surface, 5,300 square feet. There are 

 usually at dinner there 180 persons at one table 152 feet long by 13 feet 

 wide, which gives a contour of 2 x (152 -f 13) = 330 feet, and allows 

 each guest but 1.8 feet of space. 



At dinners, the number of waiters cannot be less than GO. There are 

 therefore 240 persons in the room. 



The cubical space to each person is then — 



200000 ^^^ ,■ -. ^ 

 -^riTT" = 833 cubic leet. 

 240 



The amount of floor-surface to each person is — 

 !,... = 22 square feet. 



Under these conditions, it is illuminated by — 



26 chandeliers, each containing 100 candles 2, 600 



Table-candelabra of 6 or 7 candles each 592 



Total number of candles 3, 192 



At the dinner given by the city to the Emperor on the occasion of his 



marriage, there were 420 persons at table. The number of waiters was 



at least 100; the cubical space for each person was then — 



200000 oo. If. 



—- = 384 cubic feet, 



520 ' 



and the floor-surface to each person — 



5300 



-^^jTT = 10 square feet. 



The room was lighted, on this occasion, by 26 chandeliers of 100 



candles each 2, 600 



Table-candelabra 592 



Total 3, 192 



Admitting that each candle develops 476 units of heat, the same as 

 a person, the total number of units of heat developed in an hour, on 

 that occasion, would be — 



(520 + 3192) X 476 = 1,766,912 units. 

 Supposing that air, at a temperature of 59°, had been admitted at a 

 height of 20 or 26 feet, and that this air, after its temperature had been 

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

 foot of air introduced would have carried off" — 



.0766 X 36 X .237 = .6536 unit. 



