THE COMB-BUILDERS 207 
of a cell on the other side, and then the width of 
the whole comb be measured, it will be found that 
the combined depth of the two cells perceptibly 
exceeds the width of the whole comb. At first 
glance this seems like a case of the less including 
the greater, which is a manifest impossibility. 
But, holding the comb up to the light, a further 
discovery is made, and the seeming paradox is. 
eliminated. The bottoms of the cells are so thin 
as to be almost transparent, and it is at once seen 
that the cells are not built end to end, in line, but 
that each cell-base on one side of the comb covers 
part of three cell-bases on the other. If the three 
diamonds, composing between them the triangular 
base of a single cell, be perforated with a needle, 
and the comb turned over, it will be found that 
the three perforations come each in a separate 
cell. Thus the saving in the total width of the 
comb is effected by allowing the pyramidal bases 
on each side to engage alternately like the teeth 
of a trap; instead of meeting point-blank, they 
overlap each other, and the faces of the pyramids 
are so contrived that each of them helps to close 
two cells. 
There is another advantage in this arrangement 
which will be immediately obvious. The apex 
and three ribs of each pyramidal cell-base form 
foundation-lines for the cell-walls on the other side 
of the comb. This means that not only do all 
cell-walls abut on an arch, but that every cell-base 
