From what we can see of the maneuvering in the lobby in certain patent extension cases now before Congress, it would seem that Col. Colt is bringing the strongest possible i nflu-ence to bear upon his case by means of a series of testimonials and certificates from gentlemen of the highest military repute in the United States army. Each of these gentlemen bears testimony to the value of . the Colonel's firearms, and declares their superiority over all others. The Secretary of War, the Hon. J. B. Floyd, remarks in his letter that "Colt's pistol has become essential to the public service." These are very flattering, and no doubt the honest expression of the testi-fiers' opinions, and at any other time weshould like to congratulate Col. Colt on their reception ; they are not addressed to him, but are addressed by the Secretary of War to the Hon. J. A Stewart, Chairman of the Committee on Patents in the House of Representatives, and are intended to have influence in that committee in giving weight to the application for a special legislative act granting a fresh lease of life to the already expired patent of Col. Colt. These testimonials appeared in the Washington Union of the 10th inst., a marked copy of which was sent to us by some one, for our perusal, and it is that perusal which has inspired us again to raise our voice against this attempted perpetration of a gross injustice. It must be recollected that Col. Colt has had all the advantages which the general law can allow to a patentee. He had first a patent of fourteen years duration, whioh was extended for seven more, and in that twenty-one years, he has made an enormous fortune, and collected around him a force of mechanical contrivances which will enable him for many years to exercise, in a great degree, a commercial monopoly without Congressional protection. But now the Colonel asks Congress to give him by special legislation what is really not his or theirs, but what belongs to the people. The patent which was Col. Colt's is now no longer such, but the free property of every one ; and on the faith of this, many valuable improvements on the original Colt pistol and rifle have been invented and patented, which could not however be used until the present time, because of the monopoly exercised by Col. Colt, and now these are being largely manufactured. The revolver has been cheapened, and can be reduced in price much lower, if the public is allowed to retain possession of what is legally its own. Should Congress grant this fresh lease, it will be in direct opposition to the principles of the fathers of our country, which were to give equal chance to every man and to abolish all monopolies after the monopolists had been suitably rewarded. It would be robbing many industrious inventors, it would be cramping the manufacturing interests, to thus tolerate the claims of one man who has already been more than amply rewarded. The principle is opposed to human justice and human reason. But a more urgent reason than this is, that the Colt pistol has become " essential to the public service," and consequently there is a large demand for them. This being the case, they should be manufactured and sold as cheaply as possible, and not monopolized by one manufactory which could charge just what it liked and bleed Uncle Sam to any extent it wished. If the public demand them, then the public should have the right of making them, when the inventor, as in this case, has been thoroughly rewarded for his invention. At the present time there are many persons I engaged in the manufacture of revolving s pistols who would all be cramped, if not ruin-a ed, by the granting of this monopoly ; and yet ! Col. Colt, with a feeling unworthy the citizen of an enlightened commonwealth, asks Congress to ruin these industrious men, and to make the government itself pay a high price for an article which it cannot do without. If Congress wishes to reward Colt, let him have a contract, but do not perpetuate or encourage this attempted imposition. From whatever point of view you look at this application, it is either one of two things —a gross absurdity or a great injustice ; and we sincerely trust that Congress will feel too much honor, and be possessed of enough common sense to prevent them from committing the one or the other, to the prejudice of the renl interests of the country generally. To return to the testimonials, we do not think that any department of the government should give its opinion or use its influence with another department, in tins or any similar case, whether solicited or otherwise. The opinion of the War Department is sufficiently apparent from the fact that they contract with Coi. Colt for a supply of his arms, without any additional testimony from the Secretary of War ; and to say the least of it, the giving of governmental certificates in sunh cases is very reprehensible policy.