WHEN the stone slabs in the Middle Gallery were raised to install a new network of under-floor conduits for power and data cabling, an unexpected but intriguing discovery was made which illuminates the design of the 17th-century laboratory originally occupying the Basement Gallery of the Museum. Two soot-encrusted rectangular channels were found just below the flagstones of the Middle Gallery floor, passing from two points in the centre of the gallery to equivalent points on the wall that separates the gallery from the stairwell.
These channels began directly above the circular recesses within the apex of the vault of the Basement Gallery from which two chandeliers had until recently been suspended. They ended at chimney breasts within the internal stairwell wall. The only conclusion that can be drawn is that the circular recesses in the vault had formerly been points of egress for smoke and fumes in the laboratory, carried along the channels within the vault, and up and out of the chimneys.
This discovery not only reveals a hidden aspect of the management of the first laboratory but is a reminder of the conditions that must have prevailed there. The arrangement of the vents was ingenious but their modest capacity would probably have coped only very slowly with the smoke, fumes and exhaust gases that the great furnaces, stills and other apparatus would have produced in quantity.