ARCHITECTURE. 



CHAPTER III. 



THE WINDOW. -GIRDERS, TIES, AND BUTTRESSES. THE 

 TUNNEL. THE SUSPENSION-BRIDGE. 



The Window, and its Modifications according to Climate. Bars and Tracery. 

 The Wheel- window and the Caddis. Curious Structure of the Caddis-tube. 

 Object of its Window. The Girder as applied to Architecture. The 

 Radius and Ulna. The Tie as appb'ed to Architecture, and its Value. Com- 

 bination of the Tie and Girder. Structure of the Crystal Palace. Leaf of 

 the Victoria Regia. A Gardener turned Architect. The Buttress in Art 

 and Nature. The Tunnel used as a Passage of Communication. Natural 

 Tunnel of the Ship-worm. The Thames Tunnel. The Piddock, or Pholas. 

 The Driver-ant. The Suspension-bridge. The Palm-wine Maker and his 

 Bridge. Suspension-bridges of Borneo and South America. The Creepers 

 and the Monkey Tribes. The Spider and Little Ermine Caterpillar. 



THE WINDOW. 



HAYING traced, though but superficially, the chief parts of 

 a building, such as the walls, the door which is opened 

 through the walls, and the roof which shelters them, we 

 naturally come to the Windows by which light is admitted to 

 them, and enemies excluded. 



There are, perhaps, few points in Architecture in which such 

 changes have been made as in the Window, which, instead of 

 being a difficulty in the way of the architect, is now valued as 

 a means of increasing the beauty of the building. Taking for 

 example even such advanced specimens of Architecture as those 

 furnished by Egypt, Greece, and Rome, we find that the 

 Window is either absent altogether, its place being supplied by 

 a hole in the roof, or that, when it is present, it was made 

 quite subordinate to the pillars and similar ornaments of the 

 building. 



This fact is, perhaps, greatly owing to the influence of climate. 

 In the parts of the world which have been mentioned in con- 



