His invention increased the number of cans one could make in an hour from six to sixty.
Fairly common in the older camps is the "hole-in-top" can.
While the first cans were opened with whatever tools were available- preferably a hammer and chisel- later cans were opened with tools specifically made for that purpose.
Early cans used metal too thick for "normal" can openers to open.
The "wheel style" opener we are all used to wasn't thought up until the mid 1920's.
Click here to see a small sample of the many can opening devices developed between the middle of the nineteenth century and the early part of the twentieth.
Methods for making cans (and can openers) improved over the years.
You can see this evolution by observing the cans you find at historic sites. Can opener development followed can development, but at a discrete distance.
The only real inference you can draw was that the opener of the can probably didn't have a can opener. Besides the common cylindrical shape we're all familiar with, there were flat rectangular shapes (sardine cans), flattened pyramid shapes (canned meats), hinged boxes (cigars and pills), rectangular tins (cooking oil), oval (powders), and custom-made odd shapes, like log-cabin-shaped syrup containers. Besides tobacco, another common find is condensed milk cans. By ascertaining the exact size, shape, and method of manufacture, you can narrow down the item that may have been in the can.
Napoleon spurred the search for preserving food when he offered a prize to the first person to come up with a way to preserve food for his armies. The next year, Peter Durand patented a tin-plated iron can for use as a food container, and in 1818 introduced the tin-plated can to America.
One can see the smokestacks of the mines, pouring out black smoke.
Not a garden, or even an attempt at one, did we see in this place; everybody here lives on canned goods." Most of the cans you'll run across are too rusty to readily identify what was in them, unless they have an unusual shape.
However, with a bit of detective work you can match their construction with techniques available during certain time periods, and make an educated guess as to when they were made and what was inside them.