A LOST OPPORTUNITY The class-room was very hot and a ray of dazzling sunshine quivered upon the diagrams on the yellow wall.

An electric fan hummed monotonously and buzzing flies hovered about Agatha's head.

Her face and hands were damp as she stood with knitted brows beside a tall blackboard, looking at the drowsy girls whom she was teaching inorganic chemistry.

One or two fixed their eyes on the symbols she had written; the rest had obviously given up the effort to understand the complicated formula.

In fact, they did not seem to notice that she had stopped her lecture.
For a few moments she looked about and mused.