"It's a bit difficult to say, sir," he replied at last.  "Up to now I've been thinkin' that it only meant thunder and, perhaps, heavy rain; but, now that you comes to mention it, I don't feel so very sure that there ain't wind along with it, too--perhaps one of these here tornaders.  And if that's what's brewin' we shall have to stand by, and keep our weather eye liftin'; for a tornader'd be an uncommon awk'ard customer to meet with in these here open boats."