There are still quite a few coopers in NYC, I believe, where they make the huge water barrels that sit on top of a great many buildings in the city. They are reservoirs for firefighting, as I understand it, and are still required by city code. Of Troy may know more.

When I was a very young lad we had a neighbor in rural PA who was a tinsmith. His name was Mr. Dietzel, probably couldn't read or write, but he used very large tin cans to make household items. My brother still has a watering can that is a series of conic sections soldered together at odd angles. The mathematics of such connections are very complex, apparently, and this old guy did them by eye and by hand. This is truly a lost art.


TEd