94 ANNUAL OF SCIENTIFIC DISCOVERT. 



metres, is beateil by 4 stoves, each having 15 brass gratinofs, each 

 rather more than 12 inches long by li inches wide, or little more 

 than one-fifth of an incli of grating i)cr cnljic metre to be warmed. 

 The annual consumption of gas in the cathedral above mentioned 

 is 2.210 cubic metres, costing 20 pounds; this consumption is 

 equal to 552 metres per stove, and oOO litres per four-fifths of an 

 incli square of grating. Tiie consumption in Parisian churclies 

 warmed by gas is found to agree very closely with that of the 

 catliedral of Berlin, but other cases give difl:*erent results. 



The church of St. Philippe at Berlin has a contents of 2,780 

 metres, and is heated by two stoves 1.40m. high, and 1.10m. 

 long, and G5 centimetres in width, each having 7 brass gratings IG 

 inches b}' two inches, equal to two-fifths of an inch square per cubic 

 metre of the contents of the church. The annual consumption 

 in this church is 1,485 cubic metres, or at the rate of 410 litres of 

 gas per cubic metre of contents. But this church is only warmed 

 3 times a week. 



The church of St. Catherine at Hamburg is heated by 8 gas 

 stoves, each having 32 brass gratings, 12 inches long by rather 

 more than 1^ inches wide ; the cubic contents of the edifice is 

 33,900 metres. The heating takes 3h hours, and consumes 220 

 metres of gas, costing about 27s. 6d., so that 3 litres of gas are 

 required in this church per cubic metre of cai)acity ; the tempera- 

 ture is kept up subsequently by the consumption of three-fourths 

 of a litre per cubic metre and per hour. 



In the churches of St. Mary and Nicholas in Berlin, and in 

 Paris also, a kind of large rose burner has been substituted for 

 the brass gratinj;: these are known in France as mushroom 

 burners (champigons). The result with these burners in the first 

 of the above-named churches is as follows: The cubical contents 

 of ihe building is 15,450 metres, and the consumption of gas 

 in 4 hours is 150 cubic metres, costing about 35s., and as it is 

 lieated by 10 stoves, each having 3 of these rose burners, the 

 consumption per hour is 1^ cubic metres of gas per burner, and 

 nearly 2h metres for each metre of the contents of the church. 

 In this case only we have the effect as shown by the thermometer, 

 which is to raise the temperature of the church from one degree 

 below zero to 5° above, or from below 30° to 40° F. 



In heating churches and large buildings the economj' of gas 

 exhibits itself quite diftcrently as compared with its ai)plication to 

 cooking; in the former case, the more continuous the operation 

 the less the relative cost, whereas in the latter the more frequent 

 the interruptions the greater the economy. The objection to gas 

 on account of its vitiation of the atmosphere of a building is one 

 which neither the wire grating nor the mushroom burner has yet 

 obviated. 



MIXTURE OF GAS AND AIR. 



Professors Silliman and Wurtz conclude that, — 

 1st. For any quantity of air, less than 5 j)er cent., mixed with 

 gas, the loss in candle-power due to the addition of each one per 



