Final answer:
Mark Twain's use of 'charming sport' to describe a buffalo hunt employs irony by suggesting a positive experience which is contradicted by the destructive or inelegant details of the hunt provided in the rest of the passage.
Step-by-step explanation:
When Mark Twain describes the buffalo hunt and writes "they had charming sport," he is employing irony. Irony is a literary device where the actual meaning is different from the literal meaning of the words used. In the context of the passage, Twain may have depicted a scene that was anything but 'charming.' The sport of hunting, in this scenario, could have led to unnecessary killing or suffering of animals, counterintuitive to the positive connotation of 'charming.' The rest of the passage would then reveal details that contradict the delight suggested by the phrase, such as the destructive nature of the hunt or possibly the ineptitude of the hunters. These contrasts between the expected and actual outcome highlight the irony in Twain's statement.