London, the 2nd day of May, 1814

My dear Renwick,

I trust this finds you well and that your embankment proceeds with the tenacity your father would have expected of you.

The bearers of this letter are colleagues of mine whom I commend to your confidence without reservation. They travel on a matter of some urgency which I expect you will recognise when they describe it. I ask that you extend to them whatever assistance your position permits, and that you do so with the discretion your father taught you to value.

You may have noticed, in the course of your work along the river, certain phenomena which resist the explanations of ordinary engineering. I suspect you have filed observations without knowing quite where to file them. These are the people who know where they belong.

I would not trouble you with vague counsel. You are an engineer and you will want particulars. The bearers will provide them. I ask only that you hear them out before you apply the scepticism I know you inherited along with your father’s constitution. What they describe will test that constitution. It tested mine.

Give them what they need. Trust them as you would trust me. If your father were alive, he would tell you the same, and he would add something about duty that would sound like scripture and mean every syllable.

I remain, with affection and confidence,

Harcourt