Henry Ernest Dudeney/Puzzles and Curious Problems/310 - Two Domino Squares/Solution

Puzzles and Curious Problems by Henry Ernest Dudeney: $310$

Arrange the $28$ dominoes as shown in the diagram to form two squares

so that the pips in every one of the eight sides shall add up alike.

The constant addition must of course be within limits to make the puzzle possible,

and it will be interesting to find those limits.

Of course, the dominoes need not be laid according to the rule, $6$ against $6$, blank against blank, and so on.

This solution has $22$ as the constant sum.

With $22$ as this constant sum, the corners must add to $8$,

with $23$ to $16$, with $24$ to $24$, with $25$ to $32$, with $26$ to $40$.

The constant sum cannot be less than $22$ or more than $26$.