If you look at the fork on the tandem in Neil's Patterson drawing, you will see that it has a right and left sided lamp bracket.
http://photobucket.com/
My guess is that these were used to mount two lamps at night, one for short distances and the other for long distances. That's how I do it today with handlebar mounted lamps. Handlebar mounted lamps take up a lot of valuable real estate and cannot be used for short distances when a bag is mounted on the bars.
I've been toying with the idea of brazing some nuts on a left fork blade to duplicate this set-up, but cannot find any lamp brackets for the left side.
Anybody know if they are still available ... and where to get fork-blade mounted lamp bracket nuts/studs?
Amir Avitzur
a big Patterson fan in Ramat-Gan, Israel