Hello Robert and All,

.
Robert wrote:
Obviously there is no such thing as a single 'natural comb size'; rather there is a natural range.
Dr. Elbert Jaycox spent quite a bit of time looking at cell size and  wrote that the normal hive had  many different  sizes of cells and not only one uniform size throughout the hive. In other words to say a frame is  all a certain size is hard to do. Dr. Jaycox said from his studies that bees will make cells up to 17% smaller or up to 17% larger. Dr. Jaycox also said bees 17% smaller and 17% larger will emerge from  the smaller/ larger cells.  I do not know what cell size Dr. Jaycox considered the middle figure as he does not say. .

 If I understand some recent posters correctly, they are saying that the 'natural' average is about 5.3mm. 
If 5.3mm  is the natural average then A.I.Root and others sold foundation which was a smaller unnatural size.  The term "Five cells to the inch" ( used in all old bee books) could never be interpreted as 5.3mm.   When I talked to Dadant in 1985 about cell size  . They still had the molds for the old *900* foundation. They figured the cell size at around 5.0mm to possibly 5.1mm. 

If that's correct, why did early foundation makers choose a size significantly smaller than average?
Good question Robert.  A.I. Root looked closely at cell size as did C.P. Dadant. .    I really do not know why the smaller size.   I believe the smaller cell size was the industry standard till talk of a bigger bee  by increasing cell size came along in the early part  of the  last century.   Many beekeepers in the Midwest thought a larger bee would have a longer tongue and  could gather nectar from  flowers not normally visited by honey bees .  Dr. Jaycox found that be size could be increased or decreased by a factor of 17%. Tongue size could be increased also by the 17% factor.
Most of Dr. Jaycox findings on cell size can be found in his book "Beekeeping in the Midwest" (copy 1976).

Sincerely,
Bob Harrison