carried to this camp. It was estimated to weigh about 60 pounds, and was measured-6 inches in diameter and 14 inches long. Heavy cannonading was heard about 5 p.m. last evening in a direction about 20 degrees south of east, which is the direction of Mathias Point. Twenty-five or thirty shots were heard.

On this bank, opposite the battery, for several miles the ground is low, never exceeding 20 feet in altitude. For a mile from the river the ground is lower than on the immediate bank; afterwards it rises about 50 feet. The two rebel batteries on the river are on ground about 20 feet high. There is a commanding point on this side, opposite the line of batteries and near the house of Mr. Posey, where a battery might be erected,but as the distance from it to Evansport is about 3 miles, it would be of little value to oppose those of the rebels. Mr. Posey informs me a ball from the gun on the hill passed over and beyond his house. The river here is about 2 miles wide, and small river craft pass close to the land, but I am told ships must pass within a mile of the batteries.

The estimates I give are not instrumental, but simply from my own judgment. A few hours only will be required to measure the width of the river, but it has rained so heavily last night and this morning, with little prospect of clearing up, that I cannot use a triangulating instrument at present,but will do so as soon as possible. I selected yesterday a base line about a mile long, which I will chain this morning. The are now seven days' provisions in this camp. You will please remember that my original instructions contemplated the reconnaissance to be made in six days, but subsequently I was directed to remain until further orders; hence I brought with me only some small surveying instruments. Should the erection of any work be contemplated in this vicinity, I respectfully request that a spirit-level and two leveling staffs may be sent to me.

I have the honor to be, very respectfully, your obedient servant,

R. S. WILLIAMSON,

Captain, U. S. Topographical Engineers.

Brigadier General S. WILLIAMS,

Assistant Adjutant-General, Department of the Potomac.

CAMP NEAR BUDD'S FERRY, October 22, 1861-Noon.

GENERAL: Your letter of October 21 is just received. I sent to General Williams this morning a report which I believe covers all the ground you speak of, but I will be more positive in my opinions. The river I am confident is nearly or quite 2 miles opposite the batteries. The ground for a mile back on this side is low, but there are points 20 feet above the river bank on the immediate bank where batteries can be erected. You can judge of the effect of shot or shell at such a distance. The rebels have large guns. Their works appear to be nothing but earthworks. The high ground 50 or 60 feet above the river on this side is suitable for batteries, but too distant. Shot will easily reach across, but can you destroy the enemy's works from such a distance? My information on the route led me to suppose Shipping Point and vicinity the principal locality for their batteries.

I can gain no information to induce me to suppose there are batteries at Cockpit Point; hence I went here first. The infantry travel slowly, but I made many side trips with small cavalry escort to learn the.