Jul 252016

Arthur's Seat.Edinburgh EH8 8HG

It was on Arthur’s Seat, the great volcanic plug that overlooks Edinburgh, that George Sinclair (d.1696) tested and calibrated the mercury barometer he had developed for estimating the depths of mines. In his book on hydrostatics, published in 1672, he described his barometer as well as a diving bell he had invented. Sinclair was an important advocate of the use of theoretical knowledge for practical ends. Like his contemporary Robert Boyle, Sinclair was also a strong believers in ghosts and spirits, whose existence he saw as proof of the truth of religion.

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Apr 192016

555  Castlehill, Edinburgh EH1 2ND

Old Edinburgh cistern

This ornate drinking fountain marks the site on Castle Hill where the mathematician George Sinclair constructed a cistern to supply water to the city of Edinburgh in around 1675. The original reservoir was demolished to make way for a new, larger one in 1849. Sinclair was professor of Mathematics at the University of Glasgow from 1654 to 1666.  In 1655 he made some very early descents in a diving bell off the Isle of Mull. He was not only a leading mathematician and engineer, but also an expert on demonology and author of Satan’s Invisible Works Discovered (c.1685).

Nineteenth-century drinking fountain on the site of the old Edinburgh cistern.

Nineteenth-century drinking fountain on the site of the old Edinburgh cistern.


High Street cistern, 1675

The one surviving wellhead on the High Street, originally connected to Sinclair’s Castlehill cistern. It was designed by Sir William Bruce to provide water to the people of the Old Town and built in around 1675.