Tuesday, April 29.-Redoubt C:200 men are employed night and day. The ditch is now 6 feet deep and about 7 wide. It is proposed to continue the width to 12 feet, which will require twenty-four hours more time at least. The closing of the redoubt to the rear can be commenced to-morrow morning. Parallel: in consequence of the detail being short 500 men, little progress was made in the day-time; also, the detail for the night was not filled out, and Battery Numbers 12 was opened in consequence. The branch parallel leading from main parallel to rear to Plum Tree Ravine, L, was not opened last night. It will be opened to-night. Battery Numbers 9: the detail worked very sluggishly and the platforms cannot be put in this morning, as was anticipated. It will be ready to-morrow. Battery Numbers 11 has progressed rapidly and is now ready for its platforms. Battery Numbers 12 will be ready for its platforms to-morrow morning. The magazine timbers ought to be delivered at all the above batteries to-day, and to-morrow the carpenters, with tools, nails, and spikes, ought to be on hand. Parallel between ravine and York River requires steps and banquette tread. Parallel between Battery Numbers 2 and Yorktown road requires widening, a berm, and steps. Parallel behind Battery Numbers 10 requires a little more excavation. Branch parallel traced and nearly excavated. Redoubt A will be completed to-day. Redoubt B: revetment done; parapet nearly completed; will probably be done to-day. Battery Numbers 10 ready for gun-platforms; one magazine completed, except floor; the other under way. Number of gabions ready, 176; on hand, 950; at depot at saw-mill, 276; about 400 at the Methodist Church, and about 250 distributed near batteries. The artillery has charge of lying the platforms and mounting the mortars in Battery Numbers 4. The beds for the platforms are prepared by the engineer. General Woodbury suggests that as the mechanics employed on these beds have no experience in that line, they can be usefully employed on other mortar beds. General Woodbury desires that the Fifth New Hampshire and Sixty-ninth New York Volunteer Regiments be ordered to continue on the service for which they have been detailed for four more days. I respectfully request that this may be granted. Captain Stewart reports progress on Nos. 7 and 8 and corduroy road to No. 7 and also having examined the grounds along left of line. Nothing of moment to report. Inclosed is a memorandum for reference. The following memorandum, changing the armament of Battery Numbers 13 and establishing Battery Numbers 14, is approved by the commanding general:

Battery Numbers 13 to consist of six 30-pounder Parrott guns, two on the left to be directed at the gorge of right redoubt, the other four to be directed 5 north of hospital. A change of 15 in the direction of embrasure will bring these last four to bear on Gloucester, if necessary. Battery Numbers 14 to consist of three 100-pounder Parrotts and one 100-pounder James gun,to be placed at extremity of old parallel; right cheek of embrasures to embrace the extreme right-hand effective gun of Gloucester fort. Shifting embrasures 5 or 10 will bring the big gun and water batteries of Yorktown into the field.

Wednesday, April 30.-Parallel from Battery Numbers 2 to Battery Numbers 5 completed, except leveling top of parapet. Parallel leading from Battery Numbers 5 to Redoubt A will be completed to-day. Parallel on right completed, save a few steps and a small portion of banquette. Redoubt B is essentially completed. Battery Numbers 10 finished, except placing dirt upon magazine. Battery Numbers 6: changed for mortars; will be completed to-day. Battery Numbers 1: extension for 200-pounders commenced, and will be completed to-day. Four hundred and three men of General Woodbury's brigade are engaged on bridges on south and west branch of Wormley's Creek, 415 on detached service, the re-