MECHANICS AND USEFUL ARTS. 3 



thousands of individuals, and a vast number of natural and mechanical 

 productions, many of which would be destroyed by moisture and heat, 

 is constructed so as fully to answer that end. A sort of twofold econ- 

 omy characterizes the entire building : the walls and foundations are, 

 at the same time, drains and ventilators ; the roofs, besides being the 

 most extensive of known skylights, are light-and-heat adjusters ; the 

 sash-bars not only hold the glass together, but are self-supporting ; and 

 the rafters form perfect drains for both sides of the glass, for draining 

 off internal as well as external moisture ; whilst the tops of the girders 

 are conduits also ; and the floors are dust-traps and aid in ventilation. 



Paxton' s Plan for the Exhibition Building. The peculiar structure 

 of the leaves of the gigantic water-lily suggested, in some measure, to 

 Mr. Paxton, the principle on which the Exhibition building was after- 

 wards constructed. In a lecture delivered to the Society of Arts upon 

 the details of his design for the Great Exhibition building, he exhibited 

 a specimen of the leaf, five feet in diameter, of only five days' growth ; 

 and to prove that not only the house for the flower, but the flower it- 

 self, has a striking relation to the Palace of Glass, Mr. Paxton re- 

 marked : " The under side of the leaf presents a beautiful example of 

 natural engineering in the cantilevers, which radiate from the centre, 

 where they are nearly two inches deep, with large bottom flanges, and 

 very thin middle ribs, between each pair of which are cross-girders, 

 to keep the ribs from buckling ; their depth gradually decreasing 

 towards the circumference of the leaf, where they also ramify." Upon 

 this " natural engineering," Mr. Paxton assured us that he first devised 

 the self-supporting principle, which he has applied in the roof of the 

 Great Building. 



The Lily-house was scarcely completed, when the clamorous objec- 

 tions raised to the brick-and-mortar design of the Building Committee 

 first led Mr. Paxton to consider the practicability of applying his novel 

 plan to the construction of a vast Exhibition House ; but the circum- 

 stance of the Building Committee having invited tenders for the con- 

 struction of their design was supposed to shut out fresh competitors. 

 The fact proved otherwise. Leave was granted to Mr. Paxton to bring 

 in his plan, which he undertook to complete in nine days. This was on 

 the 14th of June ; other business intervened, and it was not until the 

 18th of June that Mr. Paxton, while presiding at a railroad meeting, first 

 sketched the outline of the proposed building on a sheet of blotting 

 paper. The plans and specifications were, however, completed by the 

 28th of June, and submitted. After some delay, and various objections, 

 the committee abandoned their own design, and contracted with Messrs. 

 Fox and Henderson to construct Mr. Paxton's building for the sum of 

 79,800. To this design was added a transept, crossing nearly at its 

 centre, so as to avoid the removal of the largest and loftiest trees 

 within the area. The contractors bound themselves, for a certain sum 

 of money, and in the course of some four months, to cover eighteen 

 acres of ground with a building upwards of a third of a mile long, (1848 

 feet,) and some 408 feet broad. In order to do this, the glass-workers 

 promised to supply, in the required time, nine hundred thousand square 

 feet of glass (weighing more than 400 tons,) in separate panes, and 



