28 ANNUAL OF SCIENTIFIC DISCOVERT. 



dus submitted one of a circular building, consisting of successive 

 colonnades, placed one over the other, somewhat resembling the 

 Colosseum at Rome, and involving a new mode of joining, for which he 

 has obtained a patent. Mr. Julius W. Adams presented one of a great 

 octagonal vault or dome, supported by ribs made of fasces or clusters 

 of gas pipe. Several other plans were offered, of great beauty and 

 originality. The task of selection was difficult and delicate ; ' the 

 Board, however, after much consultation, finally determined on one 

 submitted by Messrs. Carstensen and Gildemeister, of New York. 

 These gentlemen are both foreigners, the latter having arrived recently 

 in the United States, from Copenhagen, where he was well known as 

 the designer of some of the principal public works of that city. 



The plan was adopted on the 26th of August, 1852, and no time 

 was lost in putting the work under way. 



The piece of ground on which the building stands, Reservoir 

 Square, granted by the city, was somewhat unfavorable for architect- 

 ural purposes. In other respects no better location could have been 

 found in New York, it being easily accessible from several great thor- 

 oughfares running in different directions. 



The main features of the building are as follows : It is, with the 

 exception of the floor, entirely constructed of iron and glass. The 

 general idea of the edifice is a Greek Cross, surmounted by a dome 

 at the intersection. Each diameter of the cross is 365 feet 5 inches 

 long. There are three similar entrances each 47 feet wide, and 

 approached by flights of steps. Over each front is a large semi-circular 

 fan-light, 41 feet Avide and 21 feet high, answering to the arch of the 

 nave. Each arm of the cross is on the ground plan 149 feet broad. 

 This is divided into a central nave and two aisles, on each side ; the nave 

 41, each aisle 54 feet wide. The central portion or nave is carried 

 up to the height of 6 7 feet, and the semi-circular arch by which it is 

 spanned is 41 feet broad. There are thus in effect two arched naves 

 crossing each other at right angles, 41 feet broad, 67 feet high to the 

 crown of the arch, and 365 feet long; and on each side of these 

 naves is an aisle 54 feet broad and 45 feet high. The exterior of the 

 ridge way of the nave is 71 feet. Each aisle is covered by a gallery 

 of its own width, and 24 feet from the floor. The central dome is 100 

 feet in diameter, 68 feet inside from the floor to the spring of the arch, 

 and 118 feet to the crown ; and on the outside, with the lantern, 149 

 feet. The exterior angles of the building are ingeniously filled up 

 T\rith a triangular lean-to 24 feet high, which gives the ground plan an 

 octagonal shape, each side or face being 149 feet wide. At each 

 angle is an octagonal tower 8 feet in diameter, and 75 feet high. 



Ten large, and eight winding stair-cases connect the principal floor 

 with the gallery, which opens on the three balconies that are situated 

 over the entrance halls, and afford ample space for flower decorations, 

 statues, vases, &c. The building contains, on the ground floor, 111,- 

 000 square feet of space, and in its galleries, which are 54 feet wide, 

 62,000 square feet more, making a total area of 173,000 square feet, 

 for the purposes of exhibition. There are thus on the ground floor 



