A further illustration of Messrs. Grundy's Scheme, for restoring and making perfect, the navigation of the River Witham, from Boston to Lincoln; and also for draining the low lands and fens contiguous thereto. [electronic resource] : Mr. Coppin's Scheme is here answer'd, by such stated facts, as demonstrate the said scheme to be drawn from false data, and wrong principles; contrary to experience, and the practice of the most noted drainers in the two last centuries, and opposite to the three great laws of nature. Publish'd for the use of such nobleman, gentlemen, merchants, and others, whose interest is herein concern'd. By John Grundy, agent and engineer to the honourable adventurers of deeping fens.