Watch Alastair Sim, and Margaret Rutherford, and Joyce Grenfell here.
"Give the boy who wrote his name there fifty lines."
Thus the Headmaster, noting the recently-disturbed, or grenfellated, dust.
To attend a school where the Masters were sure of themselves, and education was not confused with vocational training. To live in a world where, if a boy wrote his name in the dust, he could be "given fifty lines."
Horace? Catullus? Ovid? Or something, perhaps, once thought to be more character-building, stoic sententiae from Seneca, or lines by Virgil on nation-founding, or some sturdy standby from Caesar's Gallic Wars?