Fred, mine is a 1936/7 National Electric Hawaiian, the forerunner of the New Yorker. It has three sets of pickups: the bridge pickup, which is visible, a set of pickups under the 17th fret or so, and a set of pickups under the 28th fret or so. The neck and middle pickups are wired such that the treble side pickups on the middle and neck sets are wired together and the bass side pickups on the middle and neck pickups are wired together.
The guitar has four control knobs: MASTER CONTROL (master volume), NATURAL HAW. (bridge pickup volume), FULL TREBLE (volume for treble side middle and neck pickups), and FULL BASS (volume for bass side middle and neck pickups). There is no tone control, but you change the tone of the bridge pickup by blending in s smoother treble (with the FULL TREBLE knob) or a rounder bass (with the FULL BASS knob). You can also turn off the bridge pickup entirely and just use the middle and neck pickups - even only the top four strings or the bottom four strings (the fourth string is picked up by both the treble and bass controls).
Of course, if National says the bridge pickup is for "Natural Hawaiian" tone, I'm satisfied using that full on and messing with the others for different tones.
So here's some pics. A shot of the headstock, just because it's beautiful, as Rick's post shows:
A shot of the body:
A shot of the top neck and middle pickup sets, with the most of the guitar disassembled. You can kind of see on the middle pickup that the magnet is short, only covering the bottom four strings. You can see a little gap between the bass side and treble side pickups.
Here's a pic of the middle and bridge pickups. I pulled the bridge pickup out of its cavity so you can see where the magnets are. This pic also shows that the bass side and treble side pickups on the middle set are separate. The contours you see are the magnets.
It's such a great guitar!
... but I do refer to the case as Casper.
