The contradictory forces of progress and destruction remained a powerful spectre in the Victorian underground, but the construction of the underground railway also created social and psychological fissures in the urban psyche, while irrevocably changing London's landscape. In many ways, its dual nature is captured in the Janus-edged façade of 23 and 24 Leinster Gardens in Paddington (Fig. 2.1). At first glance, the Georgian exterior, complete with plant trimmings and iron railings, is undifferentiated from the row of terrace houses that line the elegant street. However, just beyond the veneer of gentrification, a network of railway tracks disappearing into a dark tunnel reveals one of the few visible remnants of the original Metropolitan Line, where steam-engine trains emerged for ventilation purposes.