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CONSTRUCTION OF THE BUILDING.

The ventilators.

The decoration.

Fig. 15.

“ they must exert a force equal to that of twice the transverse strength of the‘ 1 column. According to the experiments, it was found that six tons was the“ bearing weight, and 12 tons the breaking weight of the columns in the centre.“ Now, 1,060 columns multiplied by six tons, the bearing weight, was equal to“ 6,360 tons; so that it would be necessary to exert a force equal to 6,360 tons,“ at a height of 24 feet from the ground, before they would be able to blow down“ the building, and he was now treating of the building independently of its“ bracings. The greatest force of wind ever known had been computed at 22 lbs.“ to the superficial foot. Taking 28 lbs. as the force, and assuming that they‘ ‘ could have a gust of wind which would strike the whole side of the building*• from top to bottom at the same moment, the total force which could be brought“ against it would be from 1,400 to 1,500 tons. Now, they had got power to“ resist it of 6,360 tons, not taking into account the bracings and the other con-“ structions and offices which were within the building, and which must of‘‘course add to its strength. The building had been tested in the late gale, when“ Colonel Reid ascertained that the force of the wind was 194 lbs., and it did‘ ‘ no harm whatever; and that was at a time when the roof was not on, and the“ building was quite exposed.”

The ventilators, to which allusion has been made, and which are shown infig. 15, fulfil an important office in the building, acting as the organs of respiration

to the whole body. The totalsurface of ventilation is nearly50,000 superficial feet, and thewhole has been so arranged,that, by the application of oneman’s strength, at about 90different points, the whole maybe opened, closed, or set andsecured at any desired angle,simultaneously. The venti-lators themselves consist of gal-vanized iron blades of an Sform, 64 inches wide, fixed onpivots at 6 inches from centre to centre. Of these there are eight in the woodenframe inserted between the columns and the sill on the ground floor, and six in thosewhich surmount the sash-frames on the two upper stories. The section of the bladeis of a novel form, and is calculated, when open, to afford the minimum interruptionto the passage of the air, compatible with being weather-tight at all times. Toeach blade, in the centre of its length, are attached small iron brackets furnishedwith eyes, through which pins are inserted; which pins are secured m a speciesof wooden rack. These racks are connected with cranks attached to iron rods,to which a movement of torsion is conveyed by screws and powerful levers. Amoderate exertion of the strength of one man applied to one of these levers,suffices to regulate, with facility, no less than 600 feet superficial of ventilation.

Hitherto the building has been considered only in a structural point of view.The vivacity of any impression it may convey to the casual visitor will, however,probably depend more strongly on the system of decoration which it has receivedfrom Mr. OWEN Jones than on any of the constructional details we have beendescribing. That gentleman, whose studies m Egypt and in the East generally,

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