A letter to the gentlemen of the committee of London merchants, trading to North America shewing in what manner, it is apprehended, that the trade and manufactures of Britain may be affected by some late restrictions on the American commerce, and by the Operation of the Act for the Stamp Duty in America; as also how far the Freedom and Liberty of the Subjects residing in Britain, are supposed to be interested in the Preservation of the Rights of the Provinces, and in what Manner those Rights appear to be abridged by that Statute