Horizontal comb is said to occur when the apex of the hexagon cell is at the top. Vertical comb has the apex of the hexagon at the side and is in fact horizontal comb rotated through 90 degrees.

The shape of the hexagon enables it to withstand externally applied tensions and pressures in contrasting degree, dependent upon the orientation of the apex. From the diagram below it may be seen that tension applied vertically and pressure applied horizontally would flatten and elongate horizontal comb.




However a reversal of these tensions and pressures would permit the hexagon to more readily retain its shape.




This is due to the horizontal zig-zag component of the hexagon matrix being restricted regarding stretching and flattening due to the vertical ties which prevent the parallel zig-zag component from moving apart in an opposite direction. A state of equilibrium is obtained and the hexagon shape is therefore retained.



Let us now consider a rope suspended between two poles, say 30 feet apart. The rope will form a catenary and the tighter the rope the more shallow the catenary becomes. The rope is under tension in the horizontal plain and there is no need for any intermediate vertical support to aid suspension. If we now envisage this rope as an arrangement of hexagon cells, to withstand such tension the hexagon would require to be orientated with the apex at the top. It follows therefore that where the brood-nest is much broader than it is deep a similar cell orientation would be required to avoid distortion.

Ropes may also be suspended down wells, here the tension in the rope is vertical and the cells representing the rope would require the apex to be at the side to withstand the vertical tension. Once cells in the comb are filled with pollen or sealed honey the structure in that area becomes a solid mass and will not readily be subject to distortion.

The area under threat is that of the brood-nest encircled with stores which supply the circumference of the brood nest with a rigid framework. The shape of the brood-nest therefore decrees the distortional stresses that will be experienced within the nest and the type of cell orientation required to withstand such internal pressure and tension. In the conventional hive an oval brood-nest might be expected with the major axis being horizontal.

This necessitates horizontal comb hence the current foundation. However natural comb built by feral colonies in cavities deeper than they are wide produce different results. The brood-nest under these conditions will now be an oval with the major axis being vertical. The internal pressures now require the presence of vertical comb to withstand distortion.

Even with the benefit of these two structural variations the queen cannot afford to lay her eggs in total disregard to the loading of the brood-nest area. An example of the queen's balanced method of brood-nest expansion may be seen in Herrod-Hempsall's book "Bee-Keeping New and Old" page 429/430 which includes 17 photographs clearly showing this careful management.

As one might expect, with these structural considerations in mind, the larger and heavier drone cells are placed along the underside of the brood area thus again minimizing possible distortion. Bees being bees, and nature being nature, there also occurs natural comb which is a variation between the horizontal and vertical arrangement.

As previously explained, vertical comb is just horizontal comb turned through 90 degrees, but in actual fact due to the hexagon shape, the rotation need only be 30 degrees to achieve the same result.



If one took this rotation at one degree at a time there would be a further 29 variations of comb orientation between horizontal and vertical comb. Why do the bees produce such variations? This third type of comb clearly exists, it occurs regularly, and appears as horizontal comb with a downward slope of say 15 degrees. If our theory regarding distortional pressure within the brood area is valid, then surely this should hold a clue to the solution of this puzzle.

Let us consider a brood-nest that is not placed centrally within the comb and is altogether over to one side. The stresses inside this comb are neither totally vertical or horizontal but somewhere in between, let us say at an angle of 45 degrees. To compensate for this, bees re-orientate their cell construction by the same amount which gives the appearance of a downward slope of 15 degrees to normal horizontal comb. So why should the brood-nest not be centrally placed within the comb but over to one side?

May I suggest temperature variation. When comb is placed so that a temperature gradient occurs across its surface, the brood-nest may well be positioned toward the warmest edge. This theory is easily proved by observing the presence of comb with a downward slope, noting whether the slope is toward a warmer position within the hive, and that the brood-nest is off set in this direction. (Photo refers)



Am I suggesting that bees take all of these items into consideration prior to the commencement of building natural comb? Yes, I rather think I am. The period in which this thought process is being undertaken is called "Stringing" and is clearly described in T.W. Cowan's book "The Honey Bee" on page 174 fig 65 with the caption- "Festoons of Bees at Work". The fact that bees collectively obtain and evaluate information, arrive at a conclusion and jointly undertake the task, which in this case is recorded for all to understand and see, has to my mind, some very interesting implications.

- Ian