236 NATURALIST'S CABINET. 



Subterraneous passages Galleries, &c. 



rapidly as they recede, like the arches of aisles 

 in perspectives, and are soon lost among the in- 

 numerable chain hers, and nurseries behind them. 

 All these chambers and passages are arched, and 

 contribute naturally to support one another. 

 The inferior building, or assemblage of nurse- 

 ries, chambers, and passages, has a flattish roof 

 without any perforation. By this contrivance, 

 if, by accident, water should penetrate the exter- 

 nal dome, the apartments below are preserved 

 from injury. The area has also a flattish floor, 

 which is situated above the royal chamber. It 

 is likewise water-proof, and so constructed that, 

 if water get admittance, it runs off by subter- 

 raneous passages, which are cylindrical, and 

 some of them so much as even thirteen inches in 

 diameter. These subterraneous passages are 

 thicklv lined with the same kind of clav of which 



V . / 



the hill is composed : they ascend the internal 

 part of the external shell in a spiral form, and, 

 winding rouad the whole building up to the top, 

 intersect and communicate with each other at 

 different heights. From every part of these large 

 galleries a number of 1 pipes, or smaller galleries, 

 leading to different apartments of the building, 

 proceed. There are likewise a great many which 

 lead downward, by sloping descents, three and 

 four feet perpendicular under ground, among the 

 gravel, from which the labouring ants select the 

 finer parts; which, after being worked up in 

 their mouths to the consistence of mortar, be- 



