{{explanation}}
1s & 4s start on opposite side

1-8
: 1s & 4s set & cast in 1 place (2s & 3s step up/down); 1s & 4s dance 1/2
  Fig 8 round nearest end couple.  2 1 4 3
9-16
: 1s+4s dance LH across; all dance 1/2 RSh reels of 4 on sides. 4s face
  up, 1s face down.  3 4 1 2
17-24
: 3s+4s also 1s+2s dance Chain Progression:

: 1s+2s also 3s+4s 3/4 turn RH in sides, 4M+3L also 2M+1L turn LH 1.1/2
  times as ptnrs chase cl'wise 1/2 way, 3s+4s also 1s+2s turn 3/4 RH on
  sides. (3) (4) (1) (2)
25-32
: All set facing up/down, all join hands on sides & set to partner; 4s
  & 1s dance 1/2 Fig 8 round nearest end couple. (3) 4 1 (2)
33-40
: 4s+1s dance Rondette (similar to Rondel but no crossing after arches):

: 4s+1s cross (Ladies under Men's arch), meet partner & face up/down, 4s
  dance under arch made by 1s, curve out to sides, 1s+4s cross (Ladies
  under Men's arch) & out to sides. (3) 1 4 (2)