172 LECTURES. 



The plans showed the general disposition of the fresh air chambers 

 in the vaults, and the great smoke and vitiated air flues in the roof. 



Dr. Reid then concluded his remarks on the new houses of Parlia- 

 ment, stating that though alterations had been made in his plans 

 every succeeding year had confirmed him in the opinion that they 

 could not depart in any material point from the principles he had 

 advocated or the practice he had introduced without injury to the ven- 

 tilation. He added that he had reason to believe that this conclusion 

 would be placed beyond all question whenever the evidence taken at 

 arbitration should become better known ; referring to the numerous 

 works he had executed, and to the extent they had influenced others, 

 he mentioned one architect, Mr. Thomas Brown, who had applied his 

 plans in forty-eight public and private buildings. 



A large plan was then brought forward sliowing the details of the 

 principal works executed under his direction at George's Hall, Liver- 

 pool. The principal air channels were about 400 feet long, and of 

 such magnitude that any one could walk in them without inconveni- 

 ence. A central engine commanded the movement of air, and drove 

 four instruments that directed currents north or south, east or west, as 

 might be required. The great hall, the courts of law, the minor 

 courts, the library, the concert room, had the combined advantages of 

 a plenum and vacuum movement. Heat was given by coils of hot water 

 apparatus, the principal coils being each forty feet in length, ten in 

 breadth and six in depth, and auxiliary coils of steam pipe were placed 

 locally, whose action was brought into play principally in very cold 

 weather. Many portions of the structure showed special modifications 

 in the design of the interior for ventilating purposes. All the smaller 

 apartments had fire-places supplied with a soft coke that gave no smoke, 

 and the flues were all carried into four large shafts in the angles of 

 the great hall. No windows were ever opened in the great hall, law 

 courts, or concert room, but in most of the minor rooms and offices 

 windows were made in the usual manner. 



When air is supplied to large buildings, or, indeed, to any habita- 

 tions by a fixed and definite channel, it is very desirable, if it be not 

 introduced from a great hight, to pass it through a gauze in winter, 

 in such towns as London and Manchester, so as to exclude a large por- 

 tion of the soot that usually accompanies it at such periods. By taking 

 the additional precaution of making it traverse a heavy artificial shower 

 of water, which is still more purifying, if charged previously with as 

 much lime as it can dissolve, the air becomes much more refreshing. 



Thus, then, in public buildings of the highest importance the great 

 objects are, the supply of the purest accessible atmosphere ; the purifi- 

 cation of the air when requisite ; the exclusion of all sources of local 

 contamination ; the power of warming by a mild heat ; the power of 

 cooling ; valves and channels that admit of air being changed in tem- 

 perature at a moment's notice, or, at least, sooner than numbers can 

 pass out of or into the building ventilated; means for moistening air; 

 the ventilation of lamps, or the adoption of a system of lighting that 

 excludes the products of combustion ; the introduction of a plenum or 

 vacuum power, or of both, for regulating the supply of fresh air and 

 discharge of vitiated air ; and the adoption of the most extensive 



