The Phoenix and the Carpet

It began with the day when it was almost the Fifth of November, and a doubt arose in some breast-Robert's, I fancy-as to the quality of the fireworks laid in for the Guy Fawkes celebration.
'They were jolly cheap,' said whoever it was, and I think it was Robert, 'and suppose they didn't go off on the night? Those Prosser kids would have something to snigger about then.'
'The ones I got are all right,' Jane said; 'I know they are, because the man at the shop said they were worth thribble the money-'
'I'm sure thribble isn't grammar,' Anthea said.
'Of course it isn't,' said Cyril; 'one word can't be grammar all by itself, so you needn't be so jolly clever.'