average of a trifle over one mile/wholesale returns on conjecture In the space of 176 years the Lower Mississippi has shortened itself two hundred and forty-two miles. That is an average of a trifle over one mile and a third per year. Therefore, any calm person can see that in the Old Oolitic Silurian Period, just a million years ago next November, the Lower Mississippi River was upward of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing-rod. And by the same token, any person can see that seven hundred and forty-two years from now the Lower Mississippi River will be only a mile and three-quarters long, and Cairo and New Orleans will have joined streets together, and be plodding comfortably along under a single mayor and a mutual board of aldermen. There is something fascinating about science. One gets such wholesale returns on conjecture out of such a trifling investment of fact. What does the author mean by the second and last sentence? Would you please simplify the?