The rhetorical device that Mark Twain uses in the excerpt is irony.
Explanation:
Irony is a rhetorical device that uses an event or situation that is deliberately contrary to what one expects. It is used to create emphasis and to stress the intensity and exceptional quality of a given situation or event. In the case of this excerpt, Mark Twain uses the irony of being in danger while lying in bed. Being in your home and in your bed is generally considered to be a place where you are safe from harm. He seems to suggest in this passage that traveling by train is safer than being at home in bed.
as an olympic athlete myself i can say that if you give the athlete to much money to soon it wont go well they will spend the money on all the wrong things but if i give them the money in small amounts it is more likely to go to training ,food and paying coaches!!