The 4,9 m by 2,4 m shaft was designed by David Boswell Reid, known as the "grandfather of air conditioning". The purpose of the shaft was to draw cool, fresh air into the Palace of Westminster, but in practice, it failed. Until 1914, the shaft functioned as a chimney, which the shaft was converted into. In the years 2017-2021, conservation works were carried out on the shaft and an elevator was installed.
