298 INSECT ARCHITECTURE. 



between. It is likewise waterproof, and contrived 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. Smeathman measured was perfectly cylin- 

 drical, and thirteen inches in diameter. These sub- 

 terraneous passages, or galleries, are lined very thick 

 with the same kind of clay of which the hill is com- 

 posed, 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 dif- 

 ferent heights, opening either immediately in the 

 dome in various places, and into the interior build- 

 ing, the new turrets, &c, or communicating with 

 them by other galleries of different diameters, either 

 circular or oval. 



From every part of these large galleries are va- 

 rious small covert ways, or galleries leading to dif- 

 ferent parts of the building. Under ground there 

 are a great many that lead downward by sloping 

 descents, three and four feet perpendicular among 

 the gravel, whence the workers cull the finer parts, 

 which, being kneaded up in their mouths to the con- 

 sistence of mortar, becomes that solid clay or stone 

 of which their hills and all their buildings, except 

 their nurseries, are composed. Other galleries again 

 ascend, and lead out horizontally on every side, and 

 are carried under ground near to the surface a vast 

 distance : for if all the nests are destroyed within a 

 hundred yards of a house, the inhabitants of those 

 which are left unmolested farther off will still carry 

 on their subterraneous galleries, and, invading it by 

 sap and mine, do great mischief to the goods and 

 merchandizes contained it. 



It seems there is a degree of necessity for the gal- 



