marked on the map "new-cut road from Columbus to Baltimore" is superior to the orders at this season of the year, but in the winter it would be nearly impracticable, as it follows near the banks of Obion Creek for several miles.

I am, sir, very respectfully, your obedient servant,

JOSEPH DIXON,

First Lieutenant, Artillery, Staff Engineer.

[4.]

Nashville, October 5, 1861.

General A. S. JOHNSTON:

Having been solicited by others, and from my known standing with Brigadier-General Pillow, I address you on the subject of temporarily blockading the Cumberland River. The river at three points I shall present you. They are as follows: Big Horse Ford, Ingraham Shoals, and Line Island. At the Big Horse Ford you are distant thirty-seven miles from the mouth of the Cumberland by water, and eight miles to Eddyville, at which point there is a turnpike road leading to Princeton, Ky., and would be the means of embracing as much of the Cumberland River, its citizens, and roads as practicable or prudent. At this point it would require three barges to be sunk in order to impede navigation. The barges should contain rock, which is to be procured immediately at the point of operation. The rock requisite is easy of access, requires but little blasting, could be mostly raised by bars, picks, and sledges. It would require 200 tons to each boat; in all, 600 tons. this would give a dam of 360 feet by boats, with 24 additional feet of opening; in all, 384 feet, as the boats should be sunken lengthwise, with an aperture of 12 feet part, so as to admit the passage of water between, and yet not be sufficient to admit the passage of a steamer or heavy flat. The bottom of the river at this point, as well as the shores, are rock bound. The dam contemplated would be 22 feet at base, 3 1/2 feet high, with a 15-inch cone, with little or no chance for wash or settle. Were batteries erected speedily here, it would be safe to block here, but should an unforeseen rise take place in the Ohio, the back-water would come up to this point and destroy in a measure the utility of the dam. The Ingraham Shoal point would be thirteen miles higher up the river, consequently less subjected to back-water, but would leave the Princeton road exposed. At this point it would require two boats to be sunken under similar specifications as before stated, yet with one boat less and 200 tons of rock. The nature of the river at this point [is such] that there is an extensive natural bar, occupying fully one-third of the entire river, making two chutes or channels, which at low water affords 20 inches in the one and 17 in the other. The deepest chute is the main channel, and is not over 40 feet in width, with a fair bank, capable of resisting a five-mile current of water. The bottom is fine sand, shifting in its nature at the tail end of the bar, which renders navigation tedious as well as uncertain as to depth; the current two miles and a half per hour. The other chute is a hard gravel one, with much firmer banks, and with no impediment at the tail end of the bar; therefore a boat with 200 tons of rock at the mouth of each chute, sunk, would at ordinary water completely blockade the river. The material rock is three-quarters of a mile up the [river] from this point, in abundance.