At one end and square,
This is talking about the anvil, and how it is a simple tool that is square with two horns on each end. There is nothing fancy or detailed, reflecting the past and how tools and other things were made for one purpose only, and that was to get the job done.
In these modern times, tools have numerous details and parts to them. Yet here is this blacksmith who is stuck in his ways, and refuses to move forward with the rest of the world.
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