26) INSECT ARCHITECTURE. 



elevation, they then quitted their labours in the 

 upper part of the building ; they affixed to the interior 

 and upper part of each wall fragments of moistened 

 earth, in an almost horizontal direction, and in such 

 a way as to form a ledge, which, by extension, would 

 be made to join that coming from the opposite wall. 

 These ledges were about half a line in thickness ; 

 and the breadth of the galleries was, for the most 

 part, about a quarter of an inch. On one side several 

 vertical partitions were seen to form the scaffolding 

 of a lodge, which communicated with several corri- 

 dors, by apertures formed in the masonry ; on an- 

 other, a regularly-formed hall was constructed, the 

 vaulted ceiling of which was sustained by numerous 

 pillars ; further off, again, might be recognised the 

 rudiments of one of those cross-roads of which I have 

 before spoken, and in which several avenues terminate. 

 These parts of the ant-hill were the most spacious ; 

 the ants, however, did not appear embarrassed in 

 constructing the ceiling to cover them in, although 

 they were often more than two inches in breadth. 



" In the upper part of the angles formed by the 

 different walls, they laid the first foundations of this 

 ceiling, and from the top of each pillar, as from so 

 many centres, a layer of earth, horizontal and slightly 

 convex, was carried forward to meet the several 

 portions coming from different points of the large 

 public thoroughfare. 



" I sometimes, however, laboured under an ap- 

 prehension that the building could not possibly re- 

 sist its own weight, and that such extensive ceilings, 

 sustained only by a few pillars, would fall into ruin 

 from the rain which continually dropped upon them ; 

 but I was quickly convinced of their stability, from 

 observing that the earth, brought by these insects, 

 adhered at all points, on the slightest contact ; and 

 that the rain, so far from lessening the cohesion of 



