Cool things with wheels
See that post with the mail bag hanging on a bracket in the first pic? That is how the mail was transferred when the train did not stop in a town. But there should be two of them; when the train came through it would leave a bag on the first one and pick the bag off the second one. I vividly recall going with my Grandfather to the train station in Canton, NY in the early 50's: he would hang a mail bag on one of the posts, then the train would come through without slowing down, and BLAM - BLAM! The bag he hung would be gone and another bag would be swinging on the other hook!The second pic shows the sorting desk, the clerk would stand there and toss the mail into the appropriate bags.
Just posted photos of what you commented about, thought you'd love the photos!