[Extract]

Dear Sir, ー According to your request I wrote you sometime since respecting our machine,² supposing it was gone to the eastward. On finding that on proof of the navigation one instrument failed performing what was expected from it I then by letter acquainted you the proceeding was delayed until that could be repaired; which when done, another proof has been made which answers well, and every trial made requisite to the attempt respecting navigation, and everything answers well, but still, he fails on one account. He proposes going in the night, on account of safety. He always depends on fox-wood, which gives light in the dark, to fix on the points of the needle of his compass, and in his barometer, by which he may know what course to steer and the depth he is under water, both which are absolute necessity for personal safety of the navigator; but he now finds that the frost wholly destroys that quality in that wood, of which he was before ignorant, and for that reason and that alone he is obliged to desist. He was detained near two months for want of money, and before he could obtain it the season was so far advanced he was, in the manner I have now related, frustrated. I write you this with two views, first that you and those to whom you may have communicated what I wrote, may not think I have imposed upon you an idle story, and in the next place to have you enquire of Dr. Franklin wr he knows of any kind of phosphorus which will give light in the dark and not consume the air. He has tried a candle, but that destroys the air so fast he cannot remain under water long enough to effect the thing. This you may rely upon, he has made every requisite experiment in proof of the machine, and it answers expectations; what I mentioned above is only wanting. . . .

The person, the inventor of this machine, now makes all his affairs a secret even to his best friends, and I have liberty to communicate this much from him only with a view to know if Dr. Franklin knows of any kind of phosphorus that will answer his purpose; otherwise the execution must be omitted until next spring, after the frosts are past. I am therefore to request your strictest silence in that matter. I am Sir, your humble servant