2. There is a special 'piece', the Striker, which you place on your base line and use to hit the other 'coins'. Strikers are usually made of some heavy plastic, celluloid used to be favoured (and before that, ivory). The striker must always be 'flicked' by forefinger or middle finger (depending upon local rules, the thumb may be allowed for 'back' shots), and never pushed.

My Dad had that 'back shot' down to a T - thanks for the nostalgia trip!