What did Sir Charles do while he stood by the gate in The Hound of the Baskervilles?

While Sir Charles Baskerville stood by the gate, waiting to meet a lady, he smoked.

We know that he smoked for at least five or ten minutes because he had dropped ash twice from his cigar.

Sir Charles was there to meet Laura Lyons, with whom he had fallen in love.  She didn't really love him, though.  She was using him.

She was in love with the man who called himself Jack Stapleton.  She thought he would marry her if she got a divorce.  He had her arrange to meet Sir Charles to ask for money.

Stapleton has Lyons miss the meeting, but since he knows Sir Charles will be at the gate, he can scare him to death with the hound.