III.]
ISLE PLEASANT.
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place amounting in all to 1l. 18s., and that it has been accomplished by the transfer of only 2s. in money, the rest of the exchange having been effected by barter. Sometimes it happened that of three or four people each was indebted, and each had a debt owing to him of equal value but not from the same person. Their position will perhaps be made clear by the accompanying figure. The arrows → show to whom each of the four is indebted:—
Each of these four men owes and is owed 5l. Cox owes Collins 5l., and is owed the same sum by the captain, and so on all round. Now these four men, by exchanging the written promises to pay which they have respectively made, can cancel all their debts without the exchange of
