A1: Ones give right hands and the man hand the woman down as he goes across - he goes right shoulder round second woman, she goes right shoulder round second man, finishing in each other's places and acknowledging.
A2: Twos give left hands - left shoulder round same sex, to each other's place, acknowledge. All home improper.
B: (16 bars): Ones give two hands: four slow chassées down the middle as the twos chassée up the outside. Three quick changes with hands. Home, still improper. 1 man 2 woman cross; others cross. All two-hand turn.
The tune is in triple time. Read all about it at https://colinhume.com/instr.ht