2 ANNUAL OF SCIENTIFIC DISCOVERY. 



plans submitted. The building thus proposed was to have been 2200 

 feet long, 450 feet wide, with a huge dome, larger than that of St. 

 Peter's at Rome. The roof and dome were to have been of iron, and 

 not less than fifteen million of bricks were to have been used in the 

 construction of the walls. This design, although at one time fully de- 

 termined upon, was most violently opposed, both on account of the 

 injury it would do the location, and the almost necessary permanence 

 of such a huge brick and mortar edifice. To such an extent did the 

 objections to the composite design of the Building Committee prevail, 

 that the practicability of the Exhibition itself was jeopardized, when, 

 fortunately, a new design was submitted. 



Faction's Improvements in Horticultural Buildings. Among the 

 practical men to whom the first design appeared objectionable, was Mr. 

 Paxton, the celebrated horticulturist of the Duke of Devonshire's 

 princely seat of Chatsworth. Mr. Paxton had already effected many 

 improvements in horticultural buildings, by discarding, as much as pos- 

 sible, all ponderous and opaque materials in their construction. He 

 pared away all clumsy sash-bars, whose broad shadows robbed plants 

 of the sun's light and heat during the best parts of the day ; he abol- 

 ished dirty and leaking overlaps, by using large panes, and inserting 

 them in wooden grooves, rendered water-tight by a sparing use of 

 putty. Again, in plain lean-to or shed roofs, the morning and evening 

 sun presents its direct rays at a low angle, and consequently very ob- 

 liquely to the glass. At those periods, most of the rays of light and 

 heat are obstructed by the position of the glass and heavy rafters ; it 

 therefore became evident that, by placing the glass more at right 

 angles to the morning and evening rays of the sun, would be removed 

 the obstructions to rays of light entering the house at an early and late 

 hour of the day. This led to the adoption of " the ridge and furrow " 

 principle for glass roofs, which so places the glass that the rays of light 

 in mornings and evenings enter the house without obstruction, and 



^D cj 



present themselves more perpendicular to the glass when they are the 

 least powerful ; whereas at mid-day, when they are most powerful, they 

 present themselves more obliquely to the glass. Upon this principle 

 Mr. Paxton constructed a pine-house in 1833, as an experiment, which 

 continues in successful use to this day. It next became a question of 

 importance how far an extensive structure might be covered in with 

 flat ridge and furrow roofs, that is, the ridge-and-valley rafters placed 

 on a level, instead of at an inclination. Several buildings, embracing 

 more or less of this design, were accordingly constructed by Mr. Pax- 

 ton, but it was not until 1848 that the plan was fully carried out in the 

 erection of a conservatory for the reception of the gigantic water-lily 

 of South America, the Victoria Regia. This building was 60 feet in 

 length by 46 in breadth, and, although a diminutive structure when 

 compared with the Exhibition building, yet the principles upon which 

 it was constructed are the same, and may be carried out to an un- 

 limited extent. The lily house, however, was so built as to retain as 

 much heat and moisture as possible, and yet to afford a strong and 

 bright light at all seasons ; whilst, on the contrary, the Industrial 

 Building, being intended to accommodate a daily assemblage of many 



