These historical maps are the work of the late Dr. Mike Stevens
Before the Duke's canal was finished, it had grown into a much more ambitious project, crossing the Mersey and Irwell Navigation on an aqueduct (with headroom for sailing flats beneath it) in order to reach the centre of Manchester, and with a line to Runcorn, where it was proposed to lock down into the tidal Mersey for the sake of carrying to Liverpool.
The Duke's canal was very profitable, so everybody wanted follow his example, and lots of canal companies were proposed. Many of these wanted the services of James Brindley, the Duke's engineer. Brindley saw beyond the need for a lot of local canals to a vision of a nationally-connected system, and designed his "Grand Cross" to connect the main river systems, the Thames, Severn, Humber and Mersey. His vision was that this would provide the main trunk routes, to which more local canals could connect. The Grand Cross was built as four canals, the Trent & Mersey (or Grand Trunk), Staffordshire and Worcester, Oxford and Coventry Canals. By the end of this decade work had started on all four.
It was the Grand Cross canals which set the gauge of 7 x 70 ft (2.1 x 21.5 m) for the Midlands system. This almost certainly came from the need for the Trent & Mersey to tunnel under Harecastle Hill, just north of the Potteries. The expense of digging a 2,880 yard (2658 m) tunnel manually deterred Brindley from building the canal to a gauge to carry the wider flats trading off the Mersey and its linked rivers.
Many other projects grew up all over the country. Two companies, the Leeds & Liverpool and the Rochdale, planned routes to cross the Pennines. The Leeds & Liverpool ran into difficulties at once, since the business interests from the two ends of the canal could not agree about the route of its western half.
The growing importance of Birmingham and the Black Country as an industrial centre led to the creation of the Birmingham Canal, built first to connect Birmingham to coalfields at Wednesbury, but also with a line planned to reach Wolverhampton and connect to the Staffs & Worcs by a flight of 21 locks.
Further south, Brindley surveyed the Monkey Island Canal to bypass a long section of the Thames. The latter was a navigation disliked by barge and boat owners as it was much obstructed by mill-weirs and fish-weirs, by-passed only by primitive flash-locks.
The decade also saw the first of many proposals for canals linking the Bristol and English Channels, none of which were ever to come to fruition.