Can anyone help me understand what the purpose of the sector dial (also know as the scientific dial) is?
The best that I can find is that this was a dial type that was popular in the 30s/40s where the dial type either:
A) A helped measure time by dividing it into sectors (presumably giving the eye a fixed starting point and ending point to make it easier to track a set period of time?); or
B) Used to help soldiers define directions/areas when planning (presumably the same way 2 o'clock always meant to the front right of an aircraft and 6 o'clock meant your rear, as in "watch your six").
I also find myself reading in a couple different places that sector dials are highly sought after variants, but it's not clear to me why. I would think that a dial with applied indices would be more desirable than a printed dial.
Anyone else have anything they can contribute? I'm undecided on how the sector dial looks, but it helps me if I understand *why* something looks the way it does, if it serves a specific purpose.