5. Gordon is referring to various pre-1750 issues of bills of exchange that were known
collectively as “old tenor.” In 1749 these bills could be exchanged for pounds sterling
at the rate of approximately 10 to 1. In 1750, when Massachusetts returned to silver
as the basis for its currency and the piece of eight as the measure of its value,
the exchange rate fell to approximately 1:25 Massachusetts pounds lawful money per
pound sterling (John J. McCusker,
Money and Exchange in Europe and America, 1600–1775: A Handbook, Chapel Hill, 1978, p. 133, 149; see also
JA's second letter of 22 June to Vergennes,
note 4, below).