THE COLUMBIAN EXPOSITION. 



99 



ordinary bricks are laid, and the entire arch of the greenhouse 

 roof supports itself without posts, rafters or braces. The roof 

 and sides are, therefore, a continuous sheet of glass. These 

 bricks have been well tested in parts of Europe, and they are 

 found to conserve heat one-half, to render the temperature of 

 the houses uniform, and to prevent all scalding of the plants. 

 Considering the fact that no framework is required, a house 

 can be built of this material about as cheaply as in the common 

 fashion. Most greenhouse men who saw the two little exhibi- 

 tion houses at Chicago must have felt that they were too dark 

 for the growing of roses and the forcing of vegetables ; but the 

 exhibitors say that for such houses the bricks are made of clear 

 bright glass, while these were made of bottle glass. It is the 

 desire of the inventor to manufacture the bricks in this country. 

 They are recommended for skylights, porch roofs, photogra- 

 phers' studios, propagating pits, and the like. These bricks are 

 the invention of Mr. Falconnier, of Nyon, Switzerland.* The 

 prices quoted in France last year were twenty-four francs per 

 100, and about fifty are required for a square metre. 



The Front Esplanade of the Horticultural Building* C an- 

 nas. — The extreme front of the Horticultural Building stood 

 something over a hundred feet west of the lagoon, oppo- 

 site the wooded island. The exterior borders of the lagoon, 

 except the extreme north-eastern and southern arms, were 

 bounded by a perpendicular wall some four or five feet 

 high, upon which was placed a heavy balustrade. This architec- 

 tural feature served the double purpose of blending the lagoon 

 with the formal environs and of appearing to set the buildings 

 upon a platform or terrace, thereby increasing their height and 

 importance. The spaces, or level terraces, between this railing 

 and the contiguous buildings were essentially esplanades, and 

 some of them were very effective. The central and important 

 portion of the esplanade of the Horticultural Building was an 

 area about sixty feet wide and extended the length of the 

 building — 1,000 feet. Upon the east it was bounded by the 

 broad gravel walk skirting the lagoon, and on the west by 

 another thoroughfare. The centre piece of this esplanade was a 

 lily tank (A, p. 105) with masonry walls, containing forty species 

 and varieties of water-plants, shown by William Tricker, of 

 Staten Island. Nymphseas predominated, of which prominent 

 ones were Nymphcea Devoniensis var. superba, a plant with rich 

 bronze leaves and pink-red flowers ; N. gracilis, with its starry, 

 sharp-petaled, white flowers standing a foot or more above the 

 leaves, and N. Zanzibarensis and the varieties rosea and azurea, 



* Annals for 1892, 361. 



