I am very apprehensive that the Enemy are preparing armed Boats, floating Batteries and Fire Rafts at Philada with an intent to fall down upon your fleet when they are finished. The Delaware Frigate will be of the greatest Advantage to them in covering their smaller Vessels should they attack you. In my opinion there is much greater danger from an attack of this kind, than one directly in your front, because there you have the Chevaux de frize as a defence. I therefore would suggest the expediency of making an attempt to destroy the Frigate and what other preparations they are making, by surprise. I will not pretend to point out the mode to you who must be much better acquainted with things of this kind than I can possibly be, but if you think it can be done no means should be left untried to effect it. I am &c.