Who? The inventor of the caulking gun, that’s who. In 1894, that’s when.
Depending on your work, this invention – or the various iterations and improvements over the years (see one example here) – might be a wonderful or an irrelevant thing.
But if your day-to-day work or your occasional home repairs have ever called for caulking, you should bless the name of Theodore Witte, even though I find no evidence that he ever did anything else of particular note or ingenuity. Like many other inventors, Canadian and otherwise, he toiled in relative obscurity but we are the better for that toil.