This is one the novel's key lines that explicitly paints the cause of progress as just another dream-ideal, no different in essence from religion.
Of what does this new religion consist? Silver in the novel stands for dreams.
"Iron," though not a recurrent symbol, carries the feel of mechanical
barrenness and of conquest, recalling Bismarck's "blood and iron."
Material progress, as voiced by Mrs Gould, is thus the dream of a mechanical,
conquered world.