...o brighten them, after which they are brushed with ammoniacal acetate of copper, and finally polished with a hard brush well waxed. By this process many of the cast-iron monuments in the city of Paris have been copper-plated, and also the street lamp-posts. Cast-iron lamp-posts weighing 4 1/2 cwt. plated in this way cost about $40, while those of bronze of similar pattern, though weighing but 2 ...