 Rather than the usual wooden laths to support the slates, they rest on angle irons, held in place by lead nails and 'torched' on the inside with mortar.Water from the pumps was originally pumped a further uphill to the covered reservoir which Hawksley had completed in 1880.It was a huge brick-vaulted structure, with a brick building over the stairs, and a float tube to measure the water level, which was transmitted to Nottingham by telegraph.