The Double Foursome Reel

The first mention of a "double foursome" that I can find is in Atkinson's Scottish National Dances, Edinburgh, 1900. He desribes a reel which is simply two foursome reels at right angles to each other and intersecting in the middle.

Smyth writes:

At the commencement, the Gentlemen place their partners at the end of the room, and stand either before or beside them. — If before them, all the four begin at once, but if otherwise the Ladies must begin first, each person describing the figure eight, and the Gentlemen set to the Ladies alternately.

A year later, the Lowe brothers said the same.

Unfortunately this description is misleading. The figure of a reel for four people is not a figure eight, it's a figure eight with an extra loop. The Fletts kindly point this out.

The Fletts also mention that the reel should be performed "giving shoulders", that is when passing someone of the opposite sex in the reel the shoulder closest to that person should lead (so the dancers are almost back to back), while when passing someone of the same sex the outside shoulder should lead (so the dancers are almost face to face).

the Gentlemen set to the Ladies alternately means that the gentlemen finish the reel in each other's places so they are setting to the woman who is not their partner (at least the first time through, they are back with partners after the second time).

Smyth (and the Lowes) seem to suggest that only the Gentlemen set, but the Fletts say all four dancers do.

This was often danced to a strathspey/reel medley.

The earliest written description of the dance actually comes from Thomas Wilson's Analysis of Country Dancing, London, 1808 (page 120). His version is rather different. It starts with two facing couples, each couple turns (I presume a two hand turn), and then everyone turns their opposite, that repeats (turn partner, turn opposite), then the 1st couple crosses in between the second and hey with them. On the second iteration the 2nd couple cross to hey with the 1st.