In the early days, when you wanted to buy lead, you used the Latin word and asked for so many pounds of "plumbum." The man who worked with lead, making rain gutters, surveyor's weights (plumb bobs), and kitchen sinks was called a "plumbum worker." When sanitary engineering appeared in the late 1800's, everything metallic connected with it was made of lead.
All metal pipes were made of lead. Pipes were not threaded and screwed together, but joined with an overlapping layer of lead and "wiped" together. Wooden pipes were still being manufactured in 1875, but the lead worker or plumbum-man of the nineteenth century ended that industry and became the plumber of today, by way of the bathroom. Most of the great grandfathers of people living today had no bathtubs other than small portable ones.
Excerpted by Maury Tosi
From Eric Sloane's booklet American Yesterday (1956)