316 Sloan's Architectural Review and Builders' Journal. [Xov., from extraneous causes, over which the designers had no control. It was found, that, owing to the expansion and con- traction of metallic substances — such as tin, copper, lead, or iron, more or less necessary in the construction of a sky- light — caused by the remarkably sudden and severe changes from extreme heat to extreme cold, in our very variable climate, and vice-versa, it was impos- sible to keep the skylight perfectly secure and weather-proof. To obviate this defect, the conception of the new design, which we are about to describe, presented itself to the mind of our townsman and friend, who, with his usual liberality, proposed it for the bene- fit of any, who may hereafter be anxious to obtain such an accessory to their dwellings, in order that they may have the advantage of the experience he him- self has gained, and the thought and careful study he has given the subject. We cordially approve of the suggestion ; and recommend it strongly, not only for the reason, that it obviates the diffi- cultj', we have j ust alluded to, but, also, that it affords so much more available wail surface, each additional story pos- sessing equal advantages, in every way, with the other. The design, we have under discussion, is thirty-two (32) feet wide in the clear, by sixty (60) feet long, and two stories high. Each story has a wall surface eighteen feet hiarh from the floor to the cornice and springing line of the glass arch, which is the quadrant of a circle of eight feet radius, leaving a centre, or level, ceiling of sixteen (16) feet, which latter is divided into panels, ten feet wide and six inches deep. The quarter circle is all of glass, ex- cept the ribs. To form this curve, an iron arch is placed in the centre of each brick pier, the piers being ten feet be- tween centres ; these are the supporting piers or walls, and are two feet six inches on the face, with seven feet six inches openings in each space for sash. The iron bracket, in this case, is two inches thick, and, as buildings differ in width, they must be more or less, in proportion to the width of the building. An iron shoe is cast, on the bottom end, for a rest, or bearing on the wall. The top is bolted to the girder, near the end of the bracket ; and at or near the wall. This girder is 6 x 12 inches ; and is placed over each bracket, with 1-| inch cleats nailed on the sides, along the bot- tom, to serve as a bearing for the floor- ing-joists, running transverse^, which are eight inches deep. The girders have iron clamps, at each end, that extend through the wall, with a neatly finished plate; or rosette washer, on the outside. The exterior windows are ten feet high, and in sections of seven feet wide with two frames to each. The sash and frames are of the ordinary make ; and double-hung, in the usual manner, with weights and cords. These exterior windows are placed slightly above the level of the arch, or curved glass ceiling, by which arrangement, the light is refracted through them directly upon the opposite wall, and vice versa, upon the same principle, as though there were a skylight. By this means, we have the ordinary windows on the exte- rior ; and avoid all the vexations attend- ant on the ever-troublesome skylight, with the advantage of not being restrict- ed to one story. The same principle can be applied to any number of stories. By this arrangement it will at once be seen, that elongation of gallery is no longer an absolute necessity, in the en- largement of picture-space ; a most de- sirable matter, indeed, when the value of the ground to be covered is considered. Light, by this admirable arrangement, we still obtain enough of, whilst we gain the required space ; and, moreover, there is aii improvement in the light, as we add to the gallery building. The onty drawback to this, in all other respects, unquestionable improvement, is the fa- tigue of ascent. But, surely no one, with a true taste for art, would object to an effort to approach it.
