Subject

A water conduit, and point of measurement. From Wikipedia: "first mechanically pumped public water supply in London, constructed in 1582 on the site of earlier hand-pumped wells and gravity-fed conduits. The mechanism, a force pump driven by a water wheel under the northernmost arch of London Bridge, transferred water from the Thames through lead pipes to four outlets. The service was discontinued in 1603. This became the mark from which many distances to and from London were measured and the name still appears on older mileposts." The 'four outlets' were spouts, one on each face. Removed 1674. Our picture comes from the on-line "Annuls of London" by John Richardson.