why was taplow not given extra work?

Taplow was not given extra work because Mr Crocker-Harris was at the Bursar's and would be delayed there for a while. So his wife, Mrs Crocker-Harris asked the boy to run away for a quarter of an hour and then come back. But Taplow was fearful of being late if his teacher finished earlier and did not find him in his office. So, his wife said she would take the blame and in the meantime Taplow could run an errand for them that is take the prescription to the chemist and get it made up for him.