ISJO.l 



THE CIVIL ENGINEER AND ARCiUTECT S JOIJUNAL. 



389 



Fig. «.— Transverse Vie v of Ridge-antl-Furrovv Skylight. 



Fig. 7. — Lower portion of Exteiior. 



position of the jjlass and heavy rafters. This led him to the adop- 

 tion of the ridge-itnd-furrow principle, which places the glass in 



Fig. 8.— Upper portion of Exterior 



such a position that the rays of light in the mornings and eveninirs 

 enter the house without obstruction. 



In 1834, he made a fuithcr experiment on the ridge-and- 

 furrow principle, in the consti'uction of a greenhouse of con- 

 siderable dimensions, adopting a still lighter sashbar than any 

 previously used; on which account the house (altliough possess- 

 ing all tiie advantages of wood) was as light as if constructed 

 of metal. 



In 1837, in constructing the great conservatory at Chatsworth, 

 it was found desirable to contrive some means for abridging the 

 manual labour required in making the immense number of sash- 

 bars requisite. Tlie only a])paratus met with was a erooving 

 machine, which was subse(|uently so improved as to make the sa.-h- 

 bar complete. For this apparatus the Society of Arts awarded 

 Mr. Paxton a medal; and tljis machine is said to be the type 

 from which all the sashbar machines now used are taken. The 

 machine saved in expense 1400/. The length of each of the bars 

 made by it is 48 inches, only one inch shorter tlian those of the 

 Exhibition Building, therefore there was adequate experience .is 

 to the working of the sashbar machinery for the Exhibition 

 Building. 



The roof of the Exhibition Building is built on the ridge-and-fur- 

 row principle, and glazed with English sheet glass, the rafters being 

 continued in uninterrupted lines the whole length of the building. 

 The transept portion, altliough covered by a semicircular roof, is 

 likewise on tlie angular principle. All tlie roof and upright sashes 

 being made by machinery, are put together and glazed with gre:it 

 rapidity, for, being litted and finished before they are hrouglit to 



