A rolling surface or porous soil should be chosen. Other conditions are proximity to wood, water, abundant subsistence for men and horses, and railroad or water transportation. Each camp should be the rendezvous of four or eight regiments.

As some of these regiments may not be called into activity much before frost, they will have ample time to acquire discipline, habits of obedience, and tactical instruction, without which they woudl be unequal to the campaign for which they are intended.

SIMON CAMERON,

Secretary of War.

(To the Governors of Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Ohio, Indiana, Illinois, Michigan, Iowa, Wisconsin, Delaware, Maryland, Missouri, and Minnesota.)

NEW YORK, May 24, 1861.

General JOSEPH G. TOTTEN,

Chief Engineer:

SIR: The military authorities of the State of New York have determined to substitute rifle guns for the 6 and 12 pounder smooth-bore batteries now constituting the equipment of its artillery to the extent of one gun per 1,000 men of the force the State is called upon for service in the field, the desire being to have such artillery ready whenever the General Government should ask for that arm, or the State should need it at home. The same description of rifle gun has been adopted as lately ordered by the Ordnance Department from the West Point foundry. The State has ordered a gun for the 12-pounder carriage to carry rifle shot (hollow) of 2 1/2 diameters in length for distant range, 2 diameters for medium range, and 1 1/2 diameters for short ranges. For the 6-pounder carriage a lighter gun is ordered to fire a rifle shot of 2 and 1 1/2 diameters, and from the two all the present ammunition, as solid, spherical case, grape, and canister, can be indiscriminately used. The bore of those two guns is that of one present 6-pounder field piece, to wit, 3.67 diameters. The 1 1/2 diameter shot will be used as spherical case, the 2 and 2 1/2 diameter shot with bursting charges. The caissons to be provided with a small proportion of grape and canister for very short ranges and rapid fire. The Ordnance Department has ordered a lighter and a heavier gun, one of the 6- pounder carriage of 2-inch bore, the other for an 18-pounder siege carriage of the present 12-pounder bore. You will observe this State has ordered guns exclusively for the 6-pounder bore, calculated to fire indiscriminately all the present 6-pounder ammunition as well as the elongated shot for the two guns, excepting the 2 1/2 diameter shot, which must be confined to the heavy gun and for long ranges. The weight of this gun will be about 200 pounds less than that of the brass 12-pounder gun now in use mounted on the same carriage. The only difficulty in the introduction of these rifle guns with elongated shot is to carry a sufficient number of rounds in the caissons and in the limber chests. To this end the lost of different diameters in length are to be apportioned with same rounds of grape and canister in the ammunition chests, whereby the entire load shall be kept within that capable of being rapidly maneuvered by six horses.

The guns are now in process of construction and are to be delivered at the rate of one per day from and after the 26th instant, with 200