| → comes into contact with 1859 1860 1861 |
| rests on 1866 1869 1872 |
|
| → by 1859 1860 1861 1866 |
| and what is more important, labour, by 1869 1872 |
|
|
which thus tend to intersect.
each cell consists of an outer spherical
and of two, three, or more
flat surfaces, according as the cell adjoins two, three, or more other cells. When one cell
→comes into contact with
three other cells, which, from the spheres being nearly of the same size, is very frequently and necessarily the case, the three flat surfaces are united into a pyramid; and this pyramid, as Huber has remarked, is manifestly a gross imitation of the three-sided pyramidal
of the cell of the hive-bee. As in the cells of the hive-bee, so here, the three plane surfaces in any one cell necessarily enter into the construction of three adjoining cells. It is obvious that the Melipona saves
→by
this manner of building; for the flat walls between the adjoining cells are not double, but are of the same thickness as the outer spherical portions, and yet each flat portion forms a part of two cells. |
|
| Reflecting on this case, it occurred to me that if the Melipona had made its spheres at some given distance from each other, and had made them of equal sizes and had arranged them symmetrically in a double layer, the resulting structure would
have been as perfect as the comb of the hive-bee. Accordingly I wrote to Professor Miller, of Cambridge, and this geometer has kindly read over the following statement, drawn up from his information, and tells me that it is strictly correct:— |
|
| If a number of equal spheres be described with their centres placed in two parallel layers; with the centre of each sphere at the distance of radius ×
or radius × 1.41421 (or at some lesser distance), from the centres of the six surrounding spheres in the same layer; and at the same distance from the centres of the adjoining spheres in the other and parallel layer; then, if planes of intersection between the several spheres in
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