Above the whole of this ground-floor rests a thick vault of clay, which forms a strong floor for the first storey (B). This is composed of only a single room; it is put to no use, unless to isolate and support the apartments of the second floor, in the arrangement of which great care is exercised. There are no partitions on this floor, nothing but massive columns of clay to support the ceiling. These columns are more than a metre in height. It is a gigantic cathedral in which the lilliputian architects have displayed considerable art. By means of this immense empty chamber a huge reservoir of air is placed in the very centre of the construction; through the galleries in the external wall it is sufficiently renewed for the purposes of respiration without too great a change in temperature. The second storey rests on the first. To this the eggs are brought, and here the larvae go through their evolution. Partitions of clay divide the space into a few large halls (_a_); these are again subdivided, this time not by earth, which is employed throughout the rest of the building, but by materials of a more delicate kind, which are, moreover, very bad conductors of heat (_b_). It is a question, in fact, of maintaining these little chambers at an almost constant temperature, favourable for the development of the eggs. The substances utilised for this purpose are fragments of wood and of gum. The Termites glue them together and thus form the walls of these important cells. The arrangement of the top storey (D) is also disposed with a view of protecting the young who are the future of the city. It constitutes the attic, situated just beneath the cupola, and contains absolutely nothing; it simply serves to interpose beneath the summit of the edifice and the storey below a layer of air, which is a bad conductor of heat. The chamber devoted to the young is thus placed between two gaseous layers, a precaution which, combined with the choice of material, places it in the very best conditions for protection against the alternation of cold at night and torrid heat during the day. It is difficult to know which to admire most--the audacity and vastness of the labour undertaken by these insects, or the ingenious foresight by which they ensure to their delicate larvae a comfortable youth. There can be no doubt that these animals show themselves very superior to Man, taking into consideration his enormous size compared to theirs, in the art of building. Pillars, cupolas, vaults--nothing is too difficult or too complicated for these small and patient labourers.[103]