Read it through once

Hitherto, while gathering up the discourse of Mr. Brocklehurst and Miss Temple, I had not, at the same time, neglected precautions to secure my personal safety; which I thought would be effected, if I could only elude observation. To this end, I had sat well back on the form, and while seeming to be busy with my sum, had held my slate in such a manner as to conceal my face: I might have escaped notice, had not my treacherous slate somehow happened to slip from my hand, and falling with an obtrusive crash, directly drawn every eye upon me; I knew it was all over now, and, as I stooped to pick up the two fragments of slate, I rallied my forces for the worst. It came.