This, however, we could not open.

There were signs of there being a cover; certainly the upper portion and the lower were each in one piece.

The fine line, a little way from the top, appeared to be where the cover was fixed; but it was made with such exquisite fineness and finish that the joining could hardly be seen.

Certainly the top could not be moved.
We took it, that it was in some way fastened from within.

I tell you all this in order that you may understand things with which you may be in contact later.