On the plate, l. center: Butterfly monogram Signed, in pencil, on tab: Butterfly monogram and imp. Collector's mark: H S T H.S. Theobald (not in Lugt in this form, in pencil) Collection (no mark): C.W. Dowdeswell
Viewed at night from the water, a man works deep inside an interior that is brightly lit from an unseen light source. Surrounding the threshold are dark lines indicating the shadowy exterior space. To the left of the doorway is a window that is partly open to reveal a figure standing facing outward towards the viewer.
"Nocturne: Furnace" brings together in one image several of the recurring themes in Whistler's art: the nocturne itself; images of men working at forges or furnaces (in this instance perhaps a glass-blower); scenes viewed through or framed by doorways. Here, plate tone evokes the gloom of the dark canals at night and the figure of the man working at the furnace continues Whistler's interest in Dutch interiors and in images of working men.