{{explanation}}
1c start on opposite sides (1x,2,3).

1–
: 1W+2W dance BtoB, moving one place to the R **while{4}** 1M+2M set and cast one place to the L (2,1x,3) ; 1M+2M dance BtoB (2,1x,3)
9–
: 2c+1c R&L
17–
: 2W+1W+3W LSh Reel3{6} (1W through and up)
25–
: 2M+1M+3M Reel3{6} (1M through and down) | All turn P RH, finishing in triangular formation with Men with backs to the centre
33–44
: Schiehallion Reel
45–48
: All cpls turn BH to finish (2x,3,1) 

{{explanation}}
In an alternative version, [9–16] and [17–24] are interchanged, 1W starts through and down on bar 9 and all turn RH after both W and M reels.
The original may have been 40 bars. There is also a version for a 3C/4L set (8x48).