Name three observations twain makes on his train ride to st. louis

Plot summary
Twain begins his story by telling of the Mississippi river and some of its origins. He describes several facts that gives the reader a little bit of information of its discovery. After covering the history of the river, Twain shifts to his history with the river. Growing up near the river created Twain's dream as a child to become a steamboat pilot. As Twain gets into his training to pilot, he includes humor and becomes technical. Twain then moves to the 21 years that he was not on the river, then transitioning back to when he was. While piloting a steamboat, he searches for different towns, looking to talk to other pilots of what they've done and seen. 
History of the Mississippi 

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