The Bridgewater canal, which was 16kms long, was built between 1759 and 1761. At one point Brindley had to take the canal over a river. He did this by building a large aqueduct so that the canal could continue over the river. The canal was so successful in cutting the cost of transport, that the Duke of Bridgewater was able to reduce the cost of his coal.

The Duke's coal mines were adit mines. These were tunnels driven into the side of a mountain. Bridgewater instructed James Brindley to extend the canal into the coal mines. This meant that the coal could be loaded directly from the coal face onto the barges for transport. The longest part of the canal was, in fact, within the tunnels of the coal mine. The Duke of Bridgewater became very rich from his mines and even richer from the canal. He was able to charge other manufacturers for using the canal to transport goods.

Research was carried out to see how efficient this form of transport was. It was found that one horse could pull a barge with 50 tonnes of coal on board. However, the same horse could only carry 150 kgs of coal on its back or between 1 and 2 tonnes when pulling a cart (depending on the road conditions). The Duke of Bridgewater had shown that, by building a canal, goods could be transported more cheaply and efficiently than by road.

Road transport was, in any case, very primitive. Roads were often little more than  tracks which were either hard and dusty in summer or so wet in winter that carriages and wagons often stuck in the mud right up to their axles. A journey of about 300kms could take three weeks in bad weather. (The same distance can now be covered by T.G.V. in a little over one hour!)

The Duke of Bridgewater also proved that canals could recover their construction cost very quickly. They made good profit for their investors and provided manufacturers with better transport for their goods. Many people set up canal building companies all over Britain. Eventually Britain was covered by a large canal network of interconnected canals which linked the river system.

By 1800, there were over 6000 kilometres of canals in Britain. However, forty years later, canals were in decline in the face of a new and faster rival, the railways.