VOL. LXXI.] PHILOSOPHICAL TRANSACTIONS. 6/ 



gazines of provisions begin, and, being separated by small empty chambers and 

 galleries, which go round them or communicate from one to the other, are con- 

 tinued on all sides to the outer shell, and reach up within it -§- or 4 of its height, 

 leaving an open area in the middle under the dome, which very much resembles 

 the nave of an old cathedral : this is surrounded by 3 or 4 very large gothic-shaped 

 arches, which are sometimes 1 or 3 feet high next the front of the area, but 

 diminish very rapidly as they recede from it, like the arches of aisles in perspec- 

 tives, and are soon lost among the innumerable chambers and nurseries behind 

 them. All these chambers, and the passages leading to and from them, being 

 arched, they help to support each other; and while the interior large arches pre- 

 vent them falling into the centre, and keep the area open, the exterior building 

 supports them on the outside. There are, comparatively speaking, few openings 

 into the great area, and they for the most part seem intended only to admit that 

 genial warmth into the nurseries which the dome collects. The interior build- 

 ing or assemblage of nurseries, chambers, &c. has a flattish top or roof, without 

 any perforation, which would keep the apartments below dry, in case through 

 accident the dome should receive any injury and let in water; and it is never ex- 

 actly flat and uniform, because the insects are always adding to it by building 

 more chambers and nurseries: so that the divisions or columns between the future 

 arched apartments resemble the pinnacles on the fronts of some old buildings, 

 and demand particular notice, as affording one proof that for the most part the 

 insects project their arches, and do not make them by evacuation. 



The area has also a flattish floor, which lies over the royal chamber, but 

 sometimes a good height above it, having nurseries and magazines between. It 

 is likewise water-proof, and contrived, as far as we may guess, to let the water 

 off, if it should get in, and run over by some short way into the subterraneous 

 passages, which run under the lowest apartments in the hill in various directions, 

 and are of an astonishing size, being wider than the bore of a great cannon. 

 One, that Mr. S. measured, was perfectly cylindrical, and 13 inches in diameter. 

 These subterraneous passages or galleries are lined very thick with the same kind 

 of clay of which the hill is composed, and ascend the inside of the outward 

 shell in a spiral manner, and winding round the whole building up to the top, 

 intersect each other at different heights, opening either immediately in the dome 

 in various places, and into the interior building, the new turrets, &c. or com- 

 municating with them by other galleries of different bores or diameters, either 

 circular or oval. 



From every part of these large galleries are various small pipes or galleries 

 leading to different parts of the building. Under ground there are a great many 

 that lead downward by sloping descents, 3 and 4 feet perpendicular among the 

 gravel, whence the labouring termites cull the finer parts, which, being worked 



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