XVI

PREFACE.

given ; in which the canals that are completed are coloured red ;thole projected, yellow ; and the rivers, as far as they are navi-gable, blue.

Four other plates are also added, which, it is presumed, will befound useful by such as may be engaged in executing under-takings of this kind. These consist of plans, elevations, and sectionsfor a lock, aqueduct, and bridges.

The author has spared no pains in the collection of his mate-rials ; he has endeavoured to avail himself of every publicationrelative to his subject, from which he has selected the informationthat appeared to him of most importance, and which he has beenenabled to correct and enlarge, in consequence of his having beenemployed in various works of this kind in different parts of thekingdom, and in foreign countries. He is not however so vainas to suppose that he may not have committed some mistakes, not-withstanding all his attention and care ; but the liberal enquirerwill remember, that, as this species of improvement is as yet onlyin its infancy, the information necessary on the subject is moredifficult to collect, and errors less easily avoided : he can onlyfay, that he has spared no labour or attention to detect and rectifythem, and shall consider himself much obliged to any gentlemanfor friendly correction or information. He has not been solicitousto attain to elegance, but he has earnestly endeavoured to be accu-rate and perspicuous: to this praise alone he aspires, and, with amodest, but, he trusts, a well-founded confidence, submits his per-formance to the judgment of an impartial, but candid public.

CON-