However, McClellan has played the same game on the enemy in our late retreat. By keeping up a show of force in our fortifications he enabled our main forces to get under good headway for the new base of operations before being seriously molested. General Huger has since been relieved of his command in the field, it is reported for allowing McClellan to get twelve hours the start of him.

I hope that McClellan will be instructed to keep a very heavy and threatening pressure upon Richmond, so as to prevent any considerable re-enforcement of Jackson from that quarter. He can do this without any risk. He has his gunboats and fortifications to fall back upon in case of meeting with too heavy a pressure himself, and in such a case would have the choice of his ground to punish the enemy as he did before. Besides, an advance of McClellan to within striking distance of Richmond again would have an immense moral effect at the North in the way of recruiting, &c., and throughout the world, showing that he was not much hurt after all. The advantages of such an advance immediately would be incalculable and would be well worth a considerable effort, while it could be made about as well as not, as far, at any rate, as would be necessary for the desired moral effect. Once restored to within striking distance of Richmond, our prestige would again be restored almost to its former standard.

Another very valuable piece of information has just been received here from a reliable source. It is to the effect that a second Merrimac, more formidable than the first, has just been completed at Richmond and is daily expected by the citizens there to come out and clear James River. This vessel, it seems, was commenced at Norfolk before the evacuation of that place, and the evacuation it was taken with other craft to Richmond. She is said to be of smaller dimensions and much lighter draught than the old Merrimac, but similar to her in construction and much more formidable, combining as she does all the improvements suggested by experience. Her armament is said to consist of eight guns of the most formidable construction that can be made in the Confederacy, while it is reported that a secret channel is open for her through the blockade, which can be closed at pleasure after she is out and under the protection of the guns of Fort Darling. She is described as having eight guns-one in the bow, one in the stern, and three on each side. A peculiar kind of shot have been cast expressly for her at the Tredegar Iron Works at Richmond, and as I have said, it is daily expected by the most knowing citizens there to come out and clear James River.

This information is brought by a very intelligent Irishman, thirty-four years of age, a printer by trade, who has been at work on the Examiner and Enquirer at Richmond since the last of March last, and has had all the facilities and privileges of his craft for acquiring information. He has just come within our lines with his family, consisting of a wife and three children, under a flag of truce, as a British subject. He has been aboard of the Merrimac Numbers 2 since the completion of her wood work, before she was taken across to the Manchester side of the river to be iron clad, and described her as a very formidable craft, with a most monstrous prow. I have no doubt, from what he says, but that we are destinated to soon be annoyed by Merrimac Numbers 2 on James River the same as we were in the spring on Hampton Roads by Merrimac Numbers 1. We may rest assured that the rebels will spare no means in their power to annoy and damage us and annihilate this James River campaign. They have had the means and the power to build one Merrimac and to experience her value, and I see no reason to doubt that