You clear me away with a broom and rags, yet apply me to find the guilty.

Many volumes held, while the limit is based on design; my first three are affirmations, while my last four are nothing but awkward times; I am an essential tool for travelers to preserve lives, so long as I am not empty.

Sounds like a knighted, bronzed, brew. Definitely one word, that much is true.

Sometimes I'm tied up tight, unable to move. Sometimes I journey freely, destination sure.

I climb without a ladder, I burn though there's no flame, No fire kindles me, yet I flare, I measure truth in mercury’s stare.