The Question (ID Number 8)...

Why is Ishmael seated behind a pane of glass at the beginning?

...and the response:

In the context of this work of fiction, who do you presume designed Ishmael's office? (Presumably Ishmael designed it.) What purpose did he have in mind for it? (He expected pupils to come there.) Why would he separate himself from his pupils in this way? What was his probable theory? (He thought his pupils would feel less uneasy, less intimidated if he was in "another room.") Consider how a potential new pupil would feel walking into a room that had no such partition.