Its use was manifestly to guard against surprise.

From this point only could be seen the line of the rocks all round the point.

Thus, any secret attack by boats could be made impossible.
Having hurriedly dressed myself, and taking with me both hunting-knife and revolver, I went out on the terrace, taking the precaution, unusual to me, of drawing the grille behind me and locking it.

Matters around the Castle are in far too disturbed a condition to allow the taking of any foolish chances, either in the way of being unarmed or of leaving the private entrance to the Castle open.

I found my way through the rocky passage, and climbed by the Jacob's ladder fixed on the rock--a device of convenience in time of peace--to the foot of the flagstaff.
I was all on fire with expectation, and the time of going seemed exceeding long; so I was additionally disappointed by the contrast when I did not see my Lady there when I arrived.