one o'clock
`` You will observe , ladies , '' Leofwin was saying in his purest Suffolk manner , `` that shading is done with the crayon well back , like this . '' He made a few swift lines on the corner of the System and looked up with his bright , inquisitive smile . `` Now are there any questions ? '' There was a stony silence , amid which the one o'clock whistle blew . The foreman , left in charge by Bob , rose . `` I 'm sorry , Miss Whitman , but I 'm afraid we 'll have to stop today . '' The worker 's friend and sister bowed to him and , clutching her notes and her bag , with firmly set lips and eyes fixed , marched to the door .