MESSRS. EDITORS:—After carefully perusing your strictures on tha Patent Office, published in your last number, allow mo to remind you of the saying that " one story is good until another is told." It is to be hoped that your articles have not left any of your readers in the predicament of tho Pennsylvania judge, who was perfectly able to decide the case after hearing one side, but was nonplussed on the presentation of the other side. The ideas put forth are too narrownofsuffi-ciently comprehensivejust, perhaps, when viewed with an eye single to the interest of one class of individuals, but absolutely unjust when the interest of tho whole community is taken in view. This Revisory Board, which you complain of, is, in my judgment, essential to the proper administration of the duties of the Patent Office. As you have taken the other side of the question, and as I take it for granted you aro but seeking the enlightenment of your readers, you will not close your columns to a fair discussion of the subject. It is a well-known fact that, previous, to say, 1853, it was far more difficult to obtain a patent than it is now. Since that time, patents have been issued with more regard to the increase of the revenues of the Office than to the proper validity of the patent itself. Hence it is that so many patents utterly worthless in themselves, are now before the public for sale. There are two kinds of patents taken out in this country (and it may be in others), and the precise merits of each are well-known to the inventors. Class No. 1 is that kind of patent which the inventor not only believes to be good, but is willing to expend his means or procure the assistance of his friends to demonstrate its utility previous to offering it for sale. These are commendable patents. Class No. 2, which in number exceed No. 1 (for the rejected applications may be fairly considered under this class) are those taken out for the express purpose of traffic, the inventor, caring but little for either their originality or usefulness to the public. His object is to procure a patent. He seems to be regardless of the strength of his claim, because his object is only to sellnot to introduce. It is quite common that, after having made up a claim that he or his agent supposes may pass, to request the Examiner, in case he cannot allow that claim, to suggest one that he can. I am not speaking of isolated cases, for I believe that this class predominates. Let any one examine the list of patents passed for the last seven years, and he will be utterly astounded at the barrenness of the claims, and his own inability to understand what they mean to claim as new. As I understand it (and I know nothing save that which is before the public), the object of this abused Revisory Board is to correct this; and its action is therefore commendable. It will reduce the revenues of the Patent Offiee, but, at the same time, it will lessen the loss in a tenfold degree of those persons who have been induced to embark in the enterprize and invest means in the patent, simply from the fact that it contains the great seal of the country. Many believe that a patent is incontrovertible, while it is notorious that not one in tea will stand the test of a court. The intention ought to be that when the government grants a man a patent, it should be fair to presume at the time that it is giving that which can be maintained, and the object of the Board is to approximate to that point as near as possible. It is no uncommon thing in Europe (Prussia, alone, excepted) for a patent to be granted five and six times over, to as many different individuals, and for one and the same thing. There is some excuse for this on their part. They must have revenue ; and my experience teaches me to believe that they will grant a patent for anything, without any regard for its originality, novelty or utility. Thank God, our government is in no such predicament. We can therefore afford to have a Revisory Boardnay, inventors will be benefited by it in the end. The country is flooded with patents now, and the majority are so utterly worth less that they throw discredit upon the good ones. Many a good patent now lays in the drawer of the inventor, for the want of some one to invest means to introduce it. This evil has become so great tht; a man is thought to be in a failing condition who consents to deal in patents. I am fully aware that I am tramping on the toes of patent agents ; but as I am seeking loftier results, let them stand from under. There is no reason why a man should not engage to introduce a patent to the public without being looked upon with suspicion; while it is notorious that such enterprises are viewed as a series of gambling by our business men. This difficulty would vanish if a closer scrutiny was applied to every application, and none passed which had not the stamp of originality on them. There are places in New York where any number of patents can be purchased for amounts ranging from $ 100 to $1,000. They are, it is true, worthless except for gambling purposes, and never should have, and, in my opinion, never would have been granted if this Revisoiy Board had been in existence and done its duty. FAIR PLAT. New York, Nov. 26th, 1860.