I believe the "barbers pole" was originally named from the similarity of the marks left on logs from cables towing them to sawmills. Or so I remember being told...
As a kid, I remember hearing that after the great hurricane in 1938 there was a lot of activity around the lake to try and salvage as much of the fallen timber before the bugs got to it. The solution was to get the logs into the lake and raft them to wherever they could be sawed into lumber. Supply vs. demand being what it is, a lot of those logs stayed in the lake and sank before they got towed to a mill. On a sunny day, you may still be able to see them on the bottom around the Barbers Pole. I know we could see them a "few" years ago...
The most recent pole was put in by residents on the Tuftonborough mainland. I remember it being blue / red / white with gold leaf accents. It looked good but the weather did get to it after a few years. A few of those houses have changed hands so that may have something to do with the absence as well.