From Capt. McClure's Company.

Camp Cumberland, Ky.,
May 18, 1862.

Mr. Editor: -- Our advance on Cumberland Ford cannot be much longer delayed. The loyal armament is approaching completion. I discern no basis for concealment, when the enemy know, that we have been largely reinforced, that we have constructed a floating bridge over the Cumberland, and that the disposition of our forces denote a flank movement. This information has been pompously proclaimed in some of the leading journals of the Mobocracy. I, therefore, feel at liberty to disclose the proportions and arrangements of our troops.

The 7th division of the army of the Ohio, commanded by Brig. Gen. Morgan, is composed of four brigades. The 24th brigade, commanded by Brig. Gen. Carter, is composed of 49th Ind., 3d Ky., 1st and 2d Tennessee regiments. The 25th, commanded by Brig. Gen. Spears, is composed of the 3d, 4th, 5th and 6th Tennessee. The 26th, commanded by Col. de Courcy, is composed of the 16th and 42d Ohio, the 22d and 14th Kentucky. The 27th, commanded by Col. Coburn, is composed of the 33d Ind., and 19th Ky. In the aggregate 14 regiments. Whether the infantry is to be augmented I cannot affirm. Twenty-two pieces of artillery, 18 of which are rifled, gradation in calibre from 6 to 30 pounders, constitute our batteries. The superiority of rifled over smooth bore guns is so obvious as to entreat mention. One squadron of cavalry complete the composition of the 7th division. The efficiency of cavalry has been so curtailed by the improvement of fire arms, as to render it an almost nugatory department of service in an actual engagement. The terrible cavalry charge of Echmol will perhaps never again be re-enacted.

With these forces we confront the Confederate troops, from 4,000 to 6,000 strong, entrenched at Cumberland Gap, a place of great natural strength, additionally confirmed by fortifications scientifically constructed and vigorously defended by 25 pieces of artillery. As to the ultimate success of our army I have unbounded confidence.

It is high time that the shadow of the Republic and the protection of her laws were being extended over the down-trodden people of East Tennessee. Of all spots within the broad limits of the Union, it has shown the highest devotion, the most uncomplaining fidelity to our flag.

Brow-beat, dragooned and ostracized, its people have steadfastly scorned apostasy, even when apostasy was safety. None but those who have seen them, banished from their homes, come into our lines and heard them relate the history of their treatment, can justly comprehend the amplitude of their loyalty.

The 26th brigade is far the best in this division. The soldierly qualifications and executive management of Col. de Courcy, vindicate applause. I have never before seen brigade drill, but I am informed by these who have examined the splendid troops of the Potomac, and that brave division of Gen. Buell, that few surpass the 26th brigade in discipline and drill. The 16th Ohio is the star regiment in this division. Its sanitary condition is of the most eminent standard. Its consolidate morning field report exhibits less sickness and more duty in proportion to number, that any other regiment in the division. This must be fairly ascribed to the watchful care of Drs. Brashear and Chase, seconded by the enforcement of stringent police regulations by Col. Bailey.

A short time ago the 16th drilled in the presence of Gen. Morgan. We expected almost every manoeuver embraced in English and American tactics, from the formation of a square against cavalry, whilst in echelon of company to deployments after defiles. At the conclusion of the drill, Gen. Morgan addressed us in the following complimentary terms:

Gentlemen - I congratulate, I salute you. I have heard of your discipline on the banks of the Potomac, I have heard of you at Lexington and at Frankfort. Gen. Buell told me at Nashville what I might expect of the 16th Ohio and of the excellent officer who commands you.

It may be insinuated that biased by prejudice I have indulged in wholesale laudation. I feel confident, however, of the endorsement of all impartial soldiers under whose observation this may fall.

We are elate with joy at the crowding news that the good cause is prospering. The grand army of the Union, excellently disciplined, inspired by the loftiest patriotism, gradually retrenching the confines of revolted territory, must replenish the breasts of all who despond, with the wildest enthusiasm, and admonish all who rule whether monarchial or literal, that the safety of a State rests with the love of the people.

Our Republic has become famous. Its heroism outstrips the heroism of history. It has the irregularity of genius. As a nation it may be compared to Napoleon as man. We have set England in trepidation about her navy. The panic has been transplanted to France. Iron clad steamers, an American applicability to war, have been suddenly transformed into the evidences of national strength.

Embroiled in the most disastrous domestic difficulties we have successfully escaped foreign complications. In the fine art, of diplomacy, the successors of Tallyrand, of Pitt, of Metternich, have not out-witted us. England, jilting her own opinion, has espoused the American exposition of the right of visitation and search. The connection of a revolt, which wounds the commerce of the world, unensnared in European difficulties, extols the diplomatic fact of our nation.

This war, properly composed, will be an eloquent expostulation against the base crime of disloyalty, and a bloody instruction to obedience to all future races of American citizens.

Yours, &c., A.S.M.

P.S. A train of artillery came up yesterday, two 30 pounders, two 20, and six 10 pounders, all rifled Parrots. Our brigade is under marching orders. It is the general opinion that we will advance on Cumberland Gap, in 2 or 3 days.

A.S.M.