Henry Ernest Dudeney/Puzzles and Curious Problems/308 - Domino Hollow Squares/Solution

Puzzles and Curious Problems by Henry Ernest Dudeney: $308$

It is required with the $28$ dominoes to form $7$ hollow squares, like the example given,

so that the pips in the four sides of every square shall add up alike.

All these seven squares need not have the same sum, and, of course, the example given need not be one of your set.

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Remember this rule:

If the pips on your dominoes sum, say, to $7$ (as in the first example),

and you wish the sides to add up to $3$, then $4 \times 3 - 7$ gives us $5$ as the sum of the four corners.