the route is , which meant problems with supplying adequate water. The Cam brook was an inadequate source of water above Camerton, and the mills along it had water rights. Each narrow boat travelling through the series of locks (22 of them each deep) with a 25-ton load of coal caused 85 tons of water to be discharged into the brook below the locks. As a result, the canal was designed with all 22 locks in one flight near Combe Hay and a pumping engine to raise water from the Cam; this was the first canal to depend entirely on pumping. A potential solution to the water supply problem was the use of caisson locks as proposed by Robert Weldon, three of which could replace the 22 conventional locks, because it wasted no water, but the technology had only been tried in a one-third scale prototype. Each lock was long and deep and contained a closed wooden box which could take a barge. This box moved up and down in the deep pool of water, which never left the lock. The box was demonstrated to the Prince Regent (later George IV), but had engineering problems and was never successful commercially or built elsewhere. It was temporarily replaced with an inclined plane by Benjamin Outram who had successfully installed inclined planes at the Peak Forest Canal in Derbyshire, whilst 22 locks and a Boulton & Watt Steam Pumping Station, capable of lifting 5,000 tons of water in 12 hours, were built to the latest design with metal plate clad wooden gates. Construction The two images show a spillway drain from 1796 (uncovered in 2009–10) at Upper Midford, a location where a caisson to take the canal from the level to the level at Midford Aqueduct was proposed. Each caisson would have had such a drain for maintenance purposes over the exit arch made to the same dimensions. The following extract from the Bath Herald newspaper provides the details of the chosen sites: 14 Jun 1798 Travel: Somerset coal canal – caisson cisterns to be formed at Combe Hay & nr. Midford. Sealed proposals reqd. on embanking & excavation with the masonry; or each separately – send to sub-committee, Waldegrave Arms, Radstock 20 Jul Plans & specs. on appl. For further Newspaper articles see s:Bath Georgian Newspaper - Somerset Coal Canal Paulton and Timsbury basins located between the villages of Paulton and