Look at paragraph 4 of the excerpt.
(4) Each day they got worse; soon it became clear that mere adjectives could not convey any idea of their terrors. Therefore I devised a mosquito gauge. I held up a bare hand for 5 seconds by the watch, then counted the number of borers on the back; there were 5 to
10. Each day added to the number, and when we got out to the Buffalo country, there were 15 to 25 on the one side of the hand and elsewhere in proportion. On the Nyarling, in early July, the number was increased, being now 20 to 40. On A lake, later that month, there were 50 to 60. But when we reached the Barren Grounds, the land of open breezy plains and cold water lakes, the pests were so bad that the hand held up for 5 seconds often showed from 100 to 125 long-billed mosquitoes boring away into the flesh. It was possible to number them only by killing them and counting the corpses. What wonder that all men should avoid the open plains, that are the kingdom of such a scourge.
How does this show the author refining his idea?
This shows the author refining his idea by v
directly refuting the claim of Dr. L.O. Howard.
describing the physical challenges he encountered on his journey north. providing data that shows an increasing problem as he travels north. reminding the reader of his initial idea about mosquitoes.