178 Mode of Heatifig Rooms hy Steam. 



the steam : but the memorialist found, from experience, 

 that with all these aids, the filling of the perpendicular pipes 

 with steam was attended with some difficulty. The steam, 

 \vhen first thrown in, passes up the perpendicular pipe 

 nearest to the boiler, and, being specifically lighter than air, 

 occupies the upper part of the apparatus, compressing the 

 air in the lower part of the rest of the pipes. The resist- 

 ance of the air will thus for a long time prevent the pipes 

 from being completely heated : but this difficulty is easily 

 obviated by having a valve or valves opening outwards, at 

 the lowest part of the apparatus, through which the air, 

 wheji compressed by the steam, is suffered to escape. In 

 the mill just mentioned, the lying cast iron pipe in the first 

 story is carried through the gables of the mill, and furnished 

 with valves for the egress of the air. It is unnecessary to 

 repeat, that the same valves serve for the discharge of the 

 air in heating the apparatus, and of the steam itself, when 

 its expansive force becomes too great. In both mills each 

 of the perpendicular pipes is provided with a valve, to pre- 

 vent a vacuum ; and in the second mill the lying pipes for 

 carrying the steam into the detached rooms have each two 

 valves, one opening inwards, and the other outwards. 



Certificates of five other mills being heated in a similar 

 manner, bv the direction of the memorialist, are presented 

 to the society. 



The application of the principle to buildings already con- 

 structed, it is presumed, will be sufficiently obvious from 

 the foregoing details. In new manufactories, where the 

 mode of heating may be made a part of the original plan, a 

 more convenient apparatus may be introduced. This will be 

 best explained by a description of the drawing, fig. 2., which 

 gives a section of a cotton-mill constructed in a manner 

 which the memorialist would adopt, were he to apply the 

 <tlcam apparatus to a new building, or any other that would 

 permit such an apparatus from its regular constructions. In 

 an old mill in this place, an apparatus is now erecting by 

 the advice of the memorialist, conformable to this plan, 

 ivhich is likely to be generally adopted in new cotton mills. 



'J'Ih' furnace for the boiler is shown at a. The flue of the 



furnace 



