This is the circuit used quite often as late as the 1950's in lamps
with 2 bulbs between the beds mounted on the wall in hotel rooms. It
worked like, right bed, left bed, both beds, and all off.
Sample of switch 
<<<click
to enlarge
Most 3 way switches at that time had 3 wires ... Back, Blue, Red
They did make a pull cord 3-way switch many many many years ago but I
haven't seen one for sale anywhere for 20+ years. The rotary type were
much more prevalent and are still used today. A visitor asked where he
might find one. I suggested he try a "Vintage" lamp parts
supplier or an old hardware store that may have one collecting dust on
the shelves. Can anyone out there make a suggestion?
This circuit was also used in many "Grandmothers" lamps.
Table lamps that included a night light and two headed or two part lamps
having only two bulbs.
<<<click
to enlarge