New Guv's Test 4

We have had a dayoff from the test. On Tuesday the question was "Where are the Penthouses at Haileybury?" The Penthouses are grander than they once were. They used to be two bits of corrugated iron forming a sort of metal ridge tent. They still serve the same purpose: to provide a dry place to put your tracksuit and other kit when you are playing sport in the rain. The answer is "On the edge of XX Acre."

I promised that the next question would have a musical flavour. I think this is one which Roger Bass, (HM Hailey 1986) added to the test as he thought that we should be able to answer the query of any bemused visitor who looked at the panel outside the music school and asked what it all meant.

"apta camenis"

The words come from a poem written by EH Bradby and carved in panels round the Bradby Hall. When the new Music School was opened in 1979 the 'Bridge of Sighs' was built to join it to the Bradby. The panel was removed to allow for the bridge.

Your question is: What does the writing on the panel mean?