plioceedings of tee polyteciikjc association: 1057 



Yentilation. 

 From an excellent address bj the President of the Institntion of 

 Civil Engineers in Scotland, Prof Macquorn Rankine, we select a 

 sini^de passage : A branch of sanitary engineering not less important 

 than water supply and cleansing is ventilation, but its difficulties and 

 imperfections are, in some respects, of an opposite character. In the 

 branch which deals with liquids and solids, we find that the supply 

 of pure water is comparatively easy, while the removal of refuse 

 involves matters of dispute and perplexity. In the case of ventilation, 

 on the other hand,, appliances for the removal of io\\\ air, are well 

 known and extensively used, while the supply of fresh air, though in 

 some cases sufficiently provided for, is in other cases neglected ; and 

 there are too many instances of the latter class. We too often see 

 large and splendid public halls, in which outlets for foul air have 

 been most carefully planned and executed at various points of the 

 roof, while the supply of air has been left to the casual opening 

 of a door, or to the currents which the pressure of the atmosphere 

 may cause to enter through drains and soil-pipes, or down disused 

 cjiimneys. There are many exceptions, however, to this remark to 

 be found in buildings where the supply of fresh air has been amply 

 and skillfully provided ; and the number of these exceptions is fortu- 

 nately increasing. Care should be taken not to under estimate the 

 supply of fresh air required by the inmates of a building; experience 

 has proved that each individual requires at the very least, twenty 

 cubic feet per minute, and if possible, he should be supplied with 

 thirty cubic feet. 



Gas for IIeatino Purposes. 

 Dr. Ziurek states, in Dingler's Polytechnic Journal, that gas from 

 ^e brown coal of Furstenwald, five miles from Berlin, will be made 

 on the spot, and collected in Berlin in twelve gasholders, each having 

 a capacity of 750,000 cubic feet. The gas will be carried, as usual, 

 in underground mains, and supplied mainly for heating purposes, at 

 a cost of about ten cents per 1,000 feet. At this rate, it is said, an 

 amount of gas giving the heating power of one ton of the best 

 Prussian brown coal will cost less than fifty cents. The works have 

 been constructed on such an extensive scale, that 2,500,000 cubic 

 feet of gas ean be supplied daily. 



[Inst.] 67 



