Canals and locks

Shakespeare may not always get his geography right, but he has sometimes been wrongly accused, as when in The Two Gentlemen of Verona, Valentine takes a boat from Verona to Milan. On the map, the two cities are landlocked; but in fact these and the other cities of the Po Valley were connected by a system of canals, which gave access to them from the Adriatic. It was along these waterways that stone was brought for many of their buildings.

This waterway system, elaborate now around Milan and Mantua, was apparently begun in Roman times.  There is a shortage of reference to them in Classical literature; but the presence of canals built for transport through marshy districts is familiar from Horace’s journey to Brundisium along the Appian Way (Satires I.5).

The course of the Appian Way through the Pontine Marshes, where it ran along a causeway, occasioned such problems of maintenance that before 100BC a canal was constructed to run parallel with it through that area.  It was along that stretch of canal, from Forum Appii to Feronia—which many apparently preferred to the road—that Horace and his friends travelled by night, and found their journey delayed by a sleepy boatman:

…missae pastum retinacula mulae
nauta piger saxo religat stertitque supinus.
iamque dies aderat, cum nil procedere lintrem

…the lazy boatman sent the mule to graze,
tied the hawser to a rock, lay down and snored.
And now day was dawning, when we realised
that the boat was not moving at all…

At which point one of the passengers beat both mule and boatman with a willow stick.

Canals date from prehistory, and the earliest known are probably those in China. The necessities of transport have occasioned them, and their profitability has justified the capital spent on their construction.

Canal locks likewise have a long history, and they too were used in China; but the angled lock gates, so familiar to us and present on all our canals, were invented by Leonardo da Vinci before 1500:


It can hardly be overstated to students how fascinated the Romans were with water engineering. Worth noting also is Shakespeare’s fascination with the cities of northern Italy: but they were after all the seat of the Renaissance.