What follows from these three Noes?
That Mr.James Smith must have stopped somewhere on the way to Sweden to supply his sea-larder with fresh provisions.

Where, in that case, must he stop?
Somewhere in Scotland, supposing he didn't alter his course when he was out of sight of your seaport.

Where in Scotland?
Northward on the main land, or westward at one of the islands?
Most likely on the main land, where the seaside places are largest, and where he is sure of getting all the stores he wants.

Next, what is our business?
Not to risk losing a link in the chain of evidence by missing any place where he has put his foot on shore.

Not to overshoot the mark when we want to hit it in the bull's-eye.