CENTRIFUGAL FORCE AND HORACE GREE- LEY.—Ingratitude is a vile sin, but alas, it is a very prevalent one. Our constant readers will remember that we published engravings of the static pressure—centrifugal force engine on page 339, Vol. 6, Scientific American. The description of this engine was presented in the name of Stephen Pearl Andrews, who, to his own satisfaction, proved hat there was a wonderful principle in the said engine, whereby a force was obtained which came from nothing, cost nothing, and increased by the square as the velocity of the machine was doubled. A certificate from a professor of mathematics accompanied such description, as a mark of high authority we suppose, like a scarlet feather stuck in the nose of an Indian Princess. We exposed the fallacy of the whole scheme, on page 341 said volume, but philosopher Andrews, not content with our expose of the ignorance of its advocates, must, needs reply to our strictures; this we allowed him to do on page 363, said volume, and only allowed ourselves one column to reply to his three. He made matters still worse, and exhibited the most profound ignorance of calculating the dynamic power of machines. Not yet content because we did not allow him more room in our columns, he went and found plenty of room in the " N.Y.Tribune," to publish all of his own remarksthat had appeared in the Scientific American, and many incorrect gratuitous assertions beside. At that time for at least three months, we think, two papers in this city contained two and three columns of falsehoods and personal abuse of us every week, all of which we heeded not, as we have an abiding faith that right and honesty will always triumph at last, and iniquity meet its just reward. Two years have passed away since then; one of the said papers, although of seven years' standing,|has been laid in its coffin, the other has been sold to a new proprietor and is in a very sickly condition. The " Tribune " of the 17th inst. contains an expression of gratitude from Stephen Pearl Andrews, wbidnMue* be very consoling for the abuse which Mr. Greeley allowed that gentleman to shower upon us through his paper. A discussion on Love, Marriage, and Divorce, was held in the "Tribune" between Henry James (an able writer,) Horace Greeley, and Stephen Pearl Andrews, and because Mr. Greeley acted towards him as we did, with respect to the use of the "Tribune's" columns, he has published the whole discussion in a pamphlet, with his own additions, and in his preface says :— "Horace Greeley is not a philosopher—the farthest from it in the world--------he has no grasp--------never sees down into the centre of things--------has no logical mind--------Mr. Greeley is a bigot---------Mr. Greeley is unfair, tricky, and mean--------he is practically dishonest in an eminent degree," c, c. Horace Greeley says about him:— " Our only reply to all this is very tairly exhibited in his writings, and especially in this pamphlet. The clear-sighted reader will find him clever, acute, dialectically agile and logically sharp, and, so far as he reasons from his understanding rather than his baser appetites, well worth perusing and heeding.— This pamphlet does much credit to his intellect, but at the expense of his moral nature." It would be out of place in us to make any comments on the qualifications of Horace Greely as an editor; they could not at least be disparaging respecting his ability, but he is evidently no judge of what constitutes a lo. gician, when he considers Mr. Andrews a sharp one ; his articles on the static pressure engine—that great humbug of which he was an advocate—ought to convince Mr. Greeley ol this. The " Tribune" contained a great many articles on the new centrifugal force, by which some persons, we think, were led to take stock in the Static Pressure Association. Many of our daily papers, and we blame the " Tribune " greatly for this, flatter new projects, like the static pressure engine, the Paine Light, Hot Air Power, and other humbugs, by which means many of our people are thereby deceived. The " Centrifugal Force " philosophers built one engine, which exhibited so much power coming from nothing and costing nothing, that it has not been heard from since. Probably Mr. Greeley considers that the proprietor of such a wonderful machine must be " acute and agile."