CONSTRUCTION OF THE BUILDING.

53

On the surface of tine mortar, with which the concrete was covered, was placed The bage platesa casting which has been technically called a base-plate. This casting is repre- 8sented in tig. 3. The lower part consists ofa horizontal plate, having attached to it avertical tube, corresponding in form with thecolumn which it serves to carry. The con-nection of the plate with this tube is strength-ened by shoulders. The length of the wholeof the base-plates being set north and south,in those through which roof-water is con-ducted, two sockets, issuing from the lowerpart of the tube, extend for some distance oneach side in an opposite, or eastern and west-ern direction. Into these sockets cast-ironpipes 6 inches in diameter are inserted,serving as drains to convey away the water;which, passing through the columns above,and through the hollow tubes of the base-plates, escapes into the pipes referredto, and finds its way to capacious drainssituated in the centre, and at the extremeeast-end of the building, which, in theirturn, convey the water to the main sewerin the Kensington-road. At the upper por-tion of the tube of the base-plate, four pro-jections with holes in them, are cast. Atthe foot of the column, which is of similarform to the base-plate, are similar projec-tions, with corresponding holes. The upper face of the tube, and the underface of the column, being planed perfectly flat and true, the holes cast in theprojections of the one exactly fit those cast to correspond with them in theother. Bolts having been then dropped through the holes in both are secured bynuts; and thus the column is attached to the base-plate, almost as rigidly as ifthe two had issued from one mould. As a proof of the singular accuracy withwhich the whole of these base-plates have been set upon their foundations, itmay be mentioned that in every instance, the holes in the upper face or bearingsurface of the base-plate, have precisely corresponded with those cast in theunder face of the columns, at the exact height at which it had been pre-arrangedthat they should be fixed; and the two (columns and base-plates) have beenunited without involving the necessity of inserting any packing between them.

I ieces of canvas only, cut to the exact form of the bearing surfaces, anddipped, in white lead, have been interposed, with a view to insure the jointsremaining perfectly secure and water-tight. The tops of the base-plates rise3-| inches above the ground-floor.

Those serving toconvey away roofwater;

IIo-v connectedwith columns.

Base Plate.

The columns are 8 inches in diameter, and those on the ground-floor are 18 feet The5 if inches high. The plan or horizontal section of these columns, which was thesuggestion of Mr. Barry, is well adapted for its purpose, mechanically as well asartistically, for while it presents a pleasing variation from the ordinary circularform, the different flat bands upon it afford surfaces well suited for the con-

columns: