Primitive Technology battery

 

Roman concrete: cement that doesn't crack

Many architectural projects of historic Rome would no longer were viable without Roman concrete. Also known as opus caementicium, Roman concrete changed into a hydraulic-setting cement blend which include volcanic ash and lime that, inside the phrases of Pliny the Elder, sure rock fragments into “a unmarried stone mass” and made them “impregnable to the waves and every day more potent.”

The earliest-known orientation to Roman concrete dates to twenty-five BC and is derived from a manuscript titled Ten Books on Architecture, written by way of the architect and engineer Vitruvius. Vitruvius recommends developers use volcanic ash from the town of Pozzuoli in Naples, referred to as pozzolana or pulvis puteolanus in Latin. Pozzolana have to be blended with lime at a ratio of three:1 or 2:1 if the construction is below water.

When Vitruvius wrote his Ten Accounts on Architecture, Roman concrete became nonetheless taken into consideration a novelty and used sparingly. This was modified in 64 AD, whilst an urban fireplace destroyed thirds of the imperial capital. As the stickers set out to rebuild, Nero’s constructing code known as for more potent foundations. The transfer to Roman concrete — which, proper to Pliny’s phrases, does now not crack — enabled the construction of architectural initiatives just like the Pantheon, the arena’s oldest and biggest unreinforced dome.

Baghdad battery: a rudimentary taser (for pain alleviation)

Archaeologists use the period “Baghdad battery” to consult a ceramic pot, copper tube, and iron rod that have been located in Iraq close to what became as soon as the capital of each the Parthian and next Sasanian Empire. They trust the 3 wonderful items as soon as fitted collectively to create a unmarried device. The motive of this tool, which appears to have been able to generating power, stays doubtful.

Wilhelm König, executive of the Iraq Antiquities Department — the identical employer whose employees first discovered the battery — at the beginning theorized that it became used as a galvanic cell to electroplate gadgets. This theory, even though extensively ordinary upon its preliminary guide, does now not preserve up as no electroplated objects from the identical term and location have been determined to this point.

In 1993, Paul Keyser from the College of Alberta in Edmonton formulated a exceptional, much less anachronistic and therefore more attainable speculation. The battery, he argued, functioned no longer as a galvanic cell however a local analgesic that could relieve pain thru transmitting an electrical fee. In doing so, it would have changed electric fish, which in Greco-Roman societies have been once in a while used to deal with complications, gout, and different conditions.