350 



NA TURE 



\_March 4, 1875 



dictory advices, they fixed on the arrangements advocated 

 since i860 by M. Tr^lat.* The system was found, how- 

 ever, to be ineffective. 



The question was in this state when M. C. Gamier 

 was called upon to construct the new theatre, which at 

 present justly attracts the attention of all. 



The arrangements adopted in the New Opera, without 

 being exactly new, are remarkably improved ; if the 

 principles upon which they are founded are almost the 

 same as those referred to above, an effort has been made 

 to apply them under the conditions best calulated to 

 ensure a favourable result. 



Of fourteen large stoves fixed in the underground part 

 of the building, some, by means of hot water, heat the 

 administrative department, the stage, and the rooms of 

 the 'artistes ; others, by hot air, the auditorium, the green 

 rooms, and the staircases. The daily consumption of 

 these fires has been estimated^ at 10,000 kilogrammes of 

 coal — nearly ten tons. 



The water and air heated by the stoves are distributed 

 by brass pipes, the heating surface of which is about 

 2,250 square metres, their length nearly five kilometres. 

 Those filled with hot water are contained in grooves 

 in the masonry ; the air coming from without circu- 

 lates around their surface, is heated, and escapes by 650 

 orifices. 



For the auditorium and its approaches recourse has 

 been had to water-stoves, which give a very considerable 

 renewal of air. " The apparatus to the number of ten," 

 says M. Nuitter, " are supplied by twelve furnaces, 

 whose power represents a steam-engine of 120-horse- 

 power. It was necessary to employ apparatus of this 

 power, for as they are only used in the days of perform- 

 ance, they are not kept constantly lighted, and they must 

 rapidly raise the temperature of spaces whose capacity is 

 not less than 90,000 metres. They must, moreover, pro- 

 vide in the auditorium for a renewal of air which may 

 reach 80,030 cubic metres per hour ; thus we must reckon 



Fig. I. — Ventilation of 



■The Sj-stem of d'Arcet. 



the warm air heaters at from 600 to 700 square metres, 

 and the hot water ones at from 1,200 to 1,300 square 

 metres." 



Ventilation is effected by means of supplies of air, the 

 openings for which measure from twenty-four to thirty 

 square metres. The cupola of the auditorium is pierced 

 by bulls'-eyes, and is also supplied with openings arranged 

 above the lateral galleries. Fig. 3 shows the cupola seen 

 from above ; it shows the vast conduits which carry off the 

 internal air by means of the draught of the lustre. The 

 supplies of air are regulated by thirty-four registers, large 

 valves of if metres long and f metre high, placed around 

 the cupola. A large sheet-iron chimney, eight metres in 

 diameter, surmounts the ventilating erection, and leads to 

 the lantern which surmounts the cupola. 



Thanks to these excellent arrangements, thanks also 

 to the large proportions of the corridors, there is reason 



* " La Tlieatrc et I'Architecte." 



to hope that in the new Opera aeration will be accom- 

 plished under satisfactory conditions, and that in this 

 new building the constructors will have approached as 

 nearly as possible to that solution of a problem whose 

 difficulties have been pointed out above. 



The lighting of the New Opera has been accomplished 

 with considerable ingenuity. The whole of the gas-pipes 

 represent a length of twenty-five kilometres, on which are 

 adjusted 714 cocks. The dangers attendant on the ordi- 

 nary method of lighting a stage by naked footlights are 

 well known. The footlights of the New Opera are formed 

 of gas jets with reversed flames, each flame being com- 

 pletely enclosed, so that only the light escapes, the heat 

 being conveyed outside. Each jet is so constructed that 

 if the glass which encloses it is broken, the flame becomes 

 extinguished by an automatic arrangement. In Fig. 4, E 

 is the conducting tube of the gas. It is lighted by raising 

 it at D, above its vertical glass. When it is placed upon 



