fording the Guyandotte belly-deep to a horse, besides crossing several of its tributaries that have no bridges. As for sustenance along that route, he found it difficult to get feed for self and horse. You can now judge from this of the practicability of the march, and then all the cavalry have to do to escape is t get on their horses and ride back to Raleigh..

W. S. ROSECRANS..

HEADQUARTERS ARMY OF THE POTOMAC, OFFICE MEDICAL DIRECTION,
Washington, November 25, 1861.

General R. B. MARCY, U. S. A.,

Chief of Staff Army of the Potomac:

GENERAL: The necessity for a battery protection for the men than the common tent affords, without going into the construction of extensive huts, which would give the appearance of going into permanent winter quarters, had been for some time egging my attention. The severity of the winters in this climate renders some protection absolutely necessary, or we must expect a vast increase of disease of the respiratory organs, and unless by our system we can secure a tolerable ventilation, as well as protection against the rains, snow, and cold, we have reason to fear a prevalence of typhus and typhoid fevers among the troops.

To guard against these, so far as practicable, I have the honor to suggest that in the first place, in addition to the ordinary trench about the tents, the trace of every regimental camp shall be provided with a ditch not less than 12 inches wide and deep, to secure a more perfect drainage.

Secondly. That an inclosure equal to the base of each tent shall be constructed of small logs or poles about 3 feet in height, over the top of which the tent shall be secured to serve as a roof. Such constructions have already been made in some of the camps; they can readily be put up by the men themselves.

Upon some of the camp grounds the timber that has been felled will furnish the poles or logs. Where these are not to be had, clapboards or any cheap material will answer the purpose.

For warming the tents and drying the ground a modification of the Crimean oven, which has been devised and put in operation by Dr. McRuer, the surgeon of General Sedgwick's brigade, appears to me to be the cheapest and most effective. Dr. McRuer has submitted to me a report on this subject. General Heintzelman, who has inspected his arrangement, informs me that it appears to be perfect in all its details; that it is at the same time efficient and economical. Dr. McRuer thus describes his plan:

A trench 1 foot wide and 20 inches deep to be dug through the center and length of each tent, to be continued for 3 or 4 feet farther, terminating at once end in a covered over fire-place and at the other in a chimney. By this arrangement the fire-place and chimney are both on the outside of the tent; the fire-place is made about 2 feet wide and arching; its area gradually lessening until it terminates in a throat at the commencement of the straight trench. This part is covered with brick or stone, laid in mortar or cement; the long trench to be covered with sheet-iron in the same manner. The opposite end to the fire-place terminates in a chimney 6 or 8 feet high; the front of the fire-place to be fitted with a tight movable sheet-iron cover, in which an opening is to be made, with a sliding cover to act as a blower. By this contrivance a perfect draught may be obtained, and no more cold air admitted within the furnace than just sufficient to consume the wood and generate the amount of heat required, which not only radiates from the exposed surface of the iron plates, but is conducted throughout the ground floor of the tent so as to keep it both warm and dry, making a board floor entirely unnecessary, thereby avoiding the dampness and filth, which unavoid-