This morning there was an extremely thick fog, which greatly favoured our movements, the Americans being, I believe, totally ignorant that any alteration had taken place in the situation of our army. As soon as the fog cleared away, our artillery opened out a tremendous and thundering cannonade upon the enemy's line, which so completely astonished them, that there was not a shot returned for twenty minutes at least, so little did they expect heavy artillery there. Nay, we heard afterwards that a great number of the irregular troops were so alarmed, that they actually quitted the lines without orders, and were posting off to New Orleans, and were with great difficulty brought back again. As soon as they perceived, however, that nothing more than a cannonade was intended, and that our troops did not advance to the attack, they commenced gradually with their artillery against ours, the fire of which increasing as their confidence increased, they were not long in silencing our guns, and in dismounting some of them. The fact is, our works had been thrown up in such haste, that they were not nearly so strong as they ought to have been made, had there been more time; the consequence was, their shot penetrated into every part of our works, and caused us not only considerable loss in artillerymen, (with one officer killed,) but, as I said before, actually dismounted a great many of our guns. This consequently entirely failed of having the desired effect; but with such a very favourable opportunity as this morning's fog presented, together with the alarm and terror with which the enemy were struck on opening our artillery upon them, there is not the most distant doubt that we should have at once got possession of their lines, had we but advanced to the attack. It is true, we were not prepared for passing the ditch, having no fascines or other necessaries for that purpose; but the resistance, in my opinion, would have been so slight, that we might almost have chosen our own place to cross it; and it was not very deep at any place. The battalion of sailors were quite annoyed at being kept looking on, while so fair an opportunity, as they thought, offered, and were crying out one to another, "Why don't we go on? what is keeping us back?"

'Tis not to be doubted that the first effect of any new thing in warfare is always the most certain of producing success, particularly against inexperienced troops; but let them see and know the whole of the effects that such a thing is calculated to produce, and the alarm wears off, and confidence and courage return with wonderful rapidity. So it was here; the first fire of our guns struck them dumb with amazement and terror—But mark the contrast! Both the latter part of this day, and on the 8th, at the general attack, how little they seemed to care for all the artillery we could bring against them! Their gun, a 32-pounder, was a most bitter antagonist to our principal battery. This happened to be erected nearly in front of that part of the line where this gun was situated, and when it fired, its shot always struck the battery at the first bound, and then it ricocheted into the redoubt where I had taken up my post. General Keane, with a part of his brigade, was in this latter work, and some of them narrowly escaped the effects of the numerous balls thrown from this gun. We were told the captain of the schooner, after having been deprived of his vessel, had been appointed to the charge and management of this gun, with some of his crew to work it; and indeed it seemed very like the bitter and determined manner of our former opponent, for any of the other guns seemed like children's play to the unceasing and destructive fire of this heavy piece of ordnance. I could distinctly see that they were sailors that worked it—one of whom, a large mulatto, with a red shirt, always spunging her out after firing.

In what I am going to relate, I know I shall incur the risk of being deemed a traveller by some of my readers, but that shall not deter me from telling what I plainly and repeatedly saw with my own eyes, assisted by a glass. At the distance of three quarters of a mile, I could distinctly perceive the ball from this gun every time it was fired, it appearing like a small black spot in the midst of the column of white smoke, and which gradually grew larger in appearance as it approached us. In many instances I was providentially the cause of saving some of the men who were in the redoubt with us, because, seeing which way the ball was coming, I told them when to lie down; and on one occasion was the shave so close, that it actually carried away one of the men's packs as he lay on the ground. Another shot struck about three feet above our heads, and carried away part of a piece of timber which supported a shed just behind us.

I forgot to mention, that, after the 28th, the Americans, conceiving that the guns of the ship would be of more use if taken out and placed in batteries, this was accordingly done; the greater part of them being planted on the other side of the river, and being completely on our flank, were enabled to annoy our people considerably, who were posted near the great road.

About two or three o'clock in the afternoon of the 1st, the army began again to retire to its bivouack, leaving covering parties to protect the batteries; and after night, the whole having formed, working parties were sent to bring off as many of the heavy guns as possible. Some of these, however, they were obliged to bury in the earth, not being able to drag them away before daylight next morning. This work seemed more oppressive and fatiguing to the troops than the bringing of them up did, inasmuch as they were animated in the latter instance by the hope of their being able to effect something against the enemy through their toil and labour; but now disappointment added poignancy to their sufferings. However, although things began to assume not quite so favourable an aspect as formerly, yet every thing was borne with the greatest good-will, as they were still confident of all their laborious services being ultimately crowned with success. In all these fatiguing services, the sailors bore an ample share, and were of the very utmost benefit to the whole army, for they could readily contrive the means of moving those immense masses of metal by purchases, &c., which to a soldier would be utterly impossible. Indeed, throughout the whole service, the gallant tars deserved the very highest praise, for they were equally brave as laborious and willing.

All hands, both soldiers and sailors, had been up the whole of the night of the 31st, and now up again all night of the 1st. This was very trying, no doubt. If any thing like dissatisfaction was evinced, this incessant toil and want of rest in encountering it, arose more from a desire to be led on to the attack, than from any wish to be rid of their labours, however painful these were. As this attempt had failed, no other scheme now appeared to present itself, but a vigorous and well sustained attack on their line; for several efforts had been made to penetrate through the wood, to endeavour to ascertain whether it was possible to turn their position at that point, but all these efforts had failed. The last that was attempted was conducted by Lieutenant Wright of the engineers, but both himself and nearly all his party perished; for it seems they fell in with a body of American riflemen, who, being much better accustomed to travelling in woods than our people were, fell on them, and, as said before, nearly cut off the whole party; yet it is evident it was not utterly impassable, or the two parties could not have met.

I do not recollect to what regiment the men belonged who accompanied Wright, but think it probable they were altogether unacquainted with that description of service, which led them into the fatal snare in which they fell. I am confident I saw blacks, who passed and repassed by the wood, but it is certain that no attempt upon a large scale could be made in that direction to turn their position; and it was probably the better plan to abandon the idea altogether. A very excellent expedient was however devised, for the purpose of turning the right flank of the enemy; it was certainly a bold and vigorous idea, and one which, if successful, would no doubt have secured to us the victory and the possession of New Orleans. This was no less than cutting a canal, in order to unite the Mississippi with the lake by which we had arrived, and by getting boats out of the latter into the river, to transport a sufficient number of men to the opposite shore, for the purpose of making a diversion in aid of the principal attack on this side.

Nothing could exceed the grandness of the conception. Accordingly, all hands were set to work to widen and deepen the rill of water which flows into the creek at the landing-place, and, continuing it up past Monsieur Villerey's house, to let it enter the river a little above that point. This, as may easily be conceived, was most laborious and dirty work; and, lest the health and spirits of the troops should suffer from such incessant fatigue, they were told off into four watches or spells, each of which followed the other in regular succession, so that the work never stood still. When it had reached near the house and high-road, screens were put up on the latter, to prevent the enemy on the opposite bank of the river from seeing what was carrying on; but as the blacks were passing and repassing almost continually by the wood, as I before mentioned, no doubt the Americans were well acquainted with what we were doing.

On the —— General Lambert arrived with the 7th and 43d regiments, to our great joy, two finer regiments not being in the service. Consequently every eye now sparkled with hope, that our labours and privations would soon terminate, as every one confidently anticipated a favourable result, and seemed still inclined to despise that enemy who had shown us that we could not do so with impunity. We were glad to meet many of our old Peninsular friends in these two fine corps, and of course welcomed them to the New World in the best manner we were capable of. They took up their ground a little in front of the canal which was cutting, there not being room sufficient for them in the line of our bivouack. We were now about 7000 effective troops, and all beginning to cheer up again, imagined nothing could withstand us.

By the 6th the canal was finished, and the boats brought up into it. There was obliged to be a lock in it at the entrance from the river, for the strength of which Sir Edward, our Chief, I understand, expressed his apprehensions, but was assured by the engineer that there was not the slightest danger. I give this merely as report.