30 ANNUAL OP SCIENTIFIC DISCOVERY. 



translucent but not transparent. The sun's rays, diffused by passing 

 through it, yield an agreeable light, and are deprived of that intensity 

 of heat and glare which belongs to them in this climate. In the 

 absence of a similar precaution in the Crystal Palace of Hyde Park, 

 whose roofs, as well as walls, were enclosed with transparent glass, it 

 was found necessary to cover the interior of the building with canvas, 

 to produce the required shade. 



The rapid and unexpected increase of the applications of exhibitors 

 induced the Association to erect a large addition to the building 

 already described. It consists of two parts, of one and two stories re- 

 spectively, and occupies the entire space between the main building 

 and the Reservoir. Its length is 451 feet and 5 inches, and its extreme 

 width is 75 feet. It is designed for the reception of machinery in mo- 

 tion, the cabinets of mining and mineralogy, and the refreshment 

 rooms, with their necessary offices. The second story, which is nearly 

 450 feet long, 21 feet wide, and extends the whole length, is entirely 

 devoted to the exhibition of pictures and statuary. It is lighted from 

 a sky-light 419 feet long, and eight feet and six inches wide. 



The decorations of the building were intrusted to Henry Greenough, 

 Esq., of Cambridge, Mass. The leading idea in the plan of decora- 

 tion, has been to bring out the beautiful construction of the building 

 to decorate construction, rather than to construct decoration. The 

 result has proved surprisingly beautiful. The colors employed on 

 the exterior are mixed in oil, the base being white lead. The exterior 

 presents the appearance of a building constructed of a light-colored 

 bronze, of which all features purely ornamental are of gold. The 

 interior has a prevailing tone of buff, or rich cream color, which is 

 given to all the cast-iron constructive work. This color is relieved by 

 a moderate and judicious use of the three positive colors, red, blue, 

 and yellow, in their several tints of vermilion, garnet, sky-blue, and 

 orange, (certain parts of the ornamental work being gilt) to accord 

 with the arrangement of colors employed in the decoration of the ceil- 

 ings. The only exceptions to the use of oil colors are the ceiling of 

 the American lean-to and the dome ; these decorations are executed 

 in tempera on canvas. 



The effect of the interior of the dome, is particularly splendid. The 

 rays from a golden sun, at the centre, descend between the latticed 

 ribs, and arabesques of white and blue, relieved by silver stars, sur- 

 round the openings. 



The whole quantity of iron employed in the construction amounts to 

 1,800 tons, of which 300 tons are wrought and 1,500 tons cast iron. The 

 quantity of glass is 15,000 panes, or 55,000 square feet. The quantity 

 of wood used amounts to 750,000 feet, board measure. 



The general mode of erection by base pieces, columns, connecting 

 pieces and girders, is the same with that of the great Hyde Park build- 

 ing ; but the construction of the arched nave, and of the dome, is of 

 course entirely peculiar, and the general effect of the building is com- 

 pletely different. The London building was certainly deficient in 

 architectural effect. The form of the New York edifice affords the 



