Thread by @ConnorTabarrok

💧Water Thread 🧵:
Civilization has always depended upon water for life. From Hunter-Gatherers and Nomads who followed rivers and migrated to pasture lands, to the first agriculturalists, water was a foundation of human life. But how did ancient people manipulate water?

Ancient peoples were not dumb. They were simply faced with hard problems. But the ingenuity of their solutions given the constraints they faced showcases their adaptive and clever minds. For many of these people, necessity drove the inventive process. See below for some examples!

As much as 3000 years ago, ancient peoples in present day Iran dug qanats, allowing them to access and transport water from mountains, hidden aquifers, and other places with a higher water table than the valleys they inhabited.

These are similar to spring-fed tunnels, with the distinction that the qanat creates the mother well, which serves as an artificial spring, whereas the spring tunnels typical of Israel started with naturally occurring springs, and were simply expanded to increase flow.

Eventually though, our ambitions to channel water grew beyond even the ability to draw it from the mountains. What if we wanted to move water against the flow of gravity? A few solutions cropped up over the centuries.

Of course, typical wells with buckets on ropes remained common, but vast improvements were made to this system by harnessing animal power. One example was the Cerd, in which an oxen is driven down a slope, pulling the rope behind it, and drawing water from the depths below.

Also notable was the Persian well, in which oxen or slaves would turn a large wheel, whose gears would eventually serve to rotate a belt of buckets or pots, which would empty at the top into a basin or channel.

In Hellenistic Egypt, a new type of pump was developed to move water over the low lying irrigation ditches that supplied the fields along the Nile with water. Known today as Archimedes’ Screw, (Even though it predates the man), this pump is incredibly useful.

The Archimedes Screw takes advantage of water’s tendency to flow to the lowest local point by chaining together a series of low points in a spiral, which, when spun, causes the water to flow progressively up the compartments of the screw, eventually discharging at the top.

These types of pumps are still used today for drainage purposes, as they can move large amounts of water with low head. Some of the most notable examples of this are in the Netherlands, where the rotation from windmills is used to power similar pumps to drain polder fields.

The Tympanum is a water wheel that not only produces mechanical energy as the rotation of it's shaft, but also lifts water to higher elevations. Dating back to the Roman empire, it was used to feed water from rivers and streams into aqueducts and cisterns. One of my favorites.

It was usually used to move water that was already running, so that it rotated without any outside energy input, but it can also be turned by man or animal power if the water is coming from a still source, such as a lake or pond.

At its heart, it's is a water wheel with the paddles fully enclosed between two planes, with a hollow shaft in the middle that allows water to flow through it. As the water flows past the wheel, and the wheel turns, the curved paddles "scoop" the water and raise it up.

Once the compartment is above the central shaft, the water then flows towards the lowest point, which is the hollow shaft, and out to whatever pipe or storage awaits it.

Some limitations of the tympanum are that it can only raise water to an elevation just under half it's total diameter, requires a running water source to power it, and cannot capture all the flow of it's source water unless it is powered by means other than flow.

The tympanum was used by the Romans to fill their aqueducts, and could be arranged in series such that it could drain extremely deep mines upon their flooding. This was used both in the mines of Roman Spain and in Wales, and preserved models have been recovered from the depths.

Similar to the tympanum, but thought to have originated as early as the 5th century BC in India, is the Noria wheel. The word "noria" comes from the Arabic term, Na-urah, meaning "the first water machine." It was the earliest mechanical device propelled by non-muscle power.

The Noria wheel is a sort of fusion between the tympanum and the bucket chain, and had the advantage of being able to raise water higher relative to its diameter, compared to the tympanum. The rotation of the shaft could also be more easily harnessed because it wasn't hollow.

The first force pump (which we might recognize as an ancestor of modern pumps) is thought to have originated in ancient Hellenistic Egypt and was contemporary to Philo of Alexandria, who authored Manuscripts of Pneumatica, dating it to somewhere around 25 B.C.

As it was a mainstay of the late roman empire, it was probably operated by slaves, which in the later centuries of the empire, made up nearly 30% of the empire’s populace. Here's a captioned drawing:

The last piece of water infra. I’ll cover is one I’ve had the pleasure of seeing in person, the stepwell. The earliest stepwell probably emerged in India somewhere around 200-400 AD. They allow access to key water resources that would otherwise be locked deep below the arid soil.

Stepwells served as cool retreats for people on hot days, and were often as much as 6° C below their surroundings. They are among the most visually stunning pieces of infrastructure I’ve come across and serve as monuments to the importance of water in our lives and history.

By surveying the ingenious water solutions of our ancestors from the aqueducts of Rome to the very first pumps, we can draw important parallels to current problems and seek new insights that may light the path to a better future. If you enjoyed the 🧵, see my blog! (Link in bio)

This thread was an adapted and extended version of a prior post, which also featured in TexasH2O magazine's Winter 2022 issue.