father took on this topic, which I have often heard argued, accords with the true spirit of the gospel; the other side is stoicism. From these last observations you will readily perceive how easy it was to impose on my father. This is the reason for his entertaining Paine. I have said that Paine was indolent. Take this as an instance: the Crisis, No. V, is but a short political essay, to be sure of great skill in the composition, of much eloquent envecfive, strong reasoning, some historic anecdote, and a fund of ridicule which fitted the passions of the times. But recollect that this piece, to Paine, was a labour of three months in the enditing. It was written in my father's house. Mr. D. Rittenhouse inhabited the front room, in the upper story, where was the library. There he kept the office of the treasury of Pennsylvania. The room of Mr. Hart and Paine was to the left hand as you come to the stairhead entering the library. When my wound, in 1778, was so far mended that, hobbling on crutches, or by creeping up stairs, as you may have seen me of late years do, my greatest recreation, in my distressed state of mind, was to get into the chamber of Mr. Rittenhouse, where the books were. There his conversation (for he was most affable) enlivened my mind, and the books would so amuse it, that it became calm; and some desperate resolutions were dissolved. While that excellent man was employing his hours in the duties of his office, for the benefit of the people, Paine would be snoring away his precious time in his easy chair, regardless of those injunctions imposed upon him by congress, in relation to his political compositions. His remissness, indolence, or vacuity of thought caused great heart-burning among many primary characters in those days. I have heard the late George Bryan, Esq. then vice president of the council, speak of his gross neglects with remarkable harshness. I would sometimes go into Paine's room, and sit with him. His Crisis, No. V. lay on his table, dusted: to-day three or four lines would be added; in the course of a week a dozen more, and so on. No. V. is dated 21st March, 1778, but it was not published until some months after that date, and it was generally thought by good whigs, that it had been too long delayed. For my own part I was so passionately engaged at heart in the principles of our cause, that Paine's manner of living and acting gave me a high disgust towards him. No idea could enter my mind, that any one, in that noble struggle, could be idle or disengaged. As to myself, my sensations were such that the example of a Decius might have been renewed. We are happy to discover in the literary productions of our countrymen a recurrence to that sobriety of phraseology that distinguished so eminently the proudest days of English letters. Having been cloyed and saturated with wordy impotence and metaphorical bombast, we gladly sit down to more temperate diet, and although to plainer, by far more invigorating fare. The present volume, with all its provincialisms, is written with spirit and patriotic energy. We see a noble character in plain and unostentatious apparel, who improves on acquaintance, and commands our respect in proportion as he becomes more familiar; a respect which the evident disparity between his language and his sentiments tends to confirm. FOR THE PORT FOLIO. PERPETUAL MOTION. MR. OLDSCHOOL, THERE is no one who has not heard of Mr. Readhefer's perpetual motion, and there are few who have not endeavoured to discover its causes, or to point out the insufficiency of the causes that have been assigned for it. In the discussions that have taken place on the subject, it has been the aim to disprove the possibility of a perpetuity of motion, abstractedly from any contrivance for the purpose, rather than to show that it cannot be produced by the arrangement of Mr. Readhefer's machine. There has yet appeared before the public no consideration of the power of the parts of this machine, either by its advocates or opponents. I am one of those who do not believe that this mechanism will effect a perpetual motion; and my reasons do not arise from the objections that may be made to the impossibility of such a motion, but from an investigation of the mechanical properties of those parts which Mr. Readhefer has combined. I drew up the following essay for my own conviction, and though the number of the advocates for the motion has very much diminished, I submit it to the perusal of the few lingerers in belief. RITTENHOUSE. By perpetual movement, in a technical sense, I mean a motion that arises from the materials that compose a machine, being arranged in such a manner, that one part of that machine may act upon another part, to begin and continue a motion, that will never cease whilst the materials last. There is a mechanical contrivance exhibited at present to the public, which is said to possess this property of creating and continuing its motion, by its construction alone; and consequently, if that construction remain unaltered, the motion must be eternal. I propose to consider the structure of this machine, and the causes of motion which are said to arise from it, and which, it is asserted by the inventor, are capable of continuing that motion forever. I will endeavour to point out all the modes in which the visible parts of this machine can act upon each other, to produce a motion, and I will demonstrate from the certain principles of mechanics, that none of the modes in which one part of the machine is attached to another, and none of the causes that have been assigned for its motion, are sufficient to give rise to a single revolution. I do not determine whether perpetual motion, according to the definition, be practicable by human art, or whether it be the cause of many of the actions that are constantly occurring throughout nature. The nearest approach we can make to truth on this subject, is, to adopt the belief of those who have understood the powers and qualities of the laws of motion, in their most varied operations and relations, or who have experimentally put them to their greatest trials. But such testimony is not sufficient to decide upon the truth or falsehood of a perpetual movement, and perhaps that is the best belief, which will continue to admit that it is possible, in the nature of things, till the Crea tor shall reveal that it is not so. But the unfolding the mystery of the possibility of perpetual motion, is a subject in which I am not concerned at present.→→ A machine is presented to us, which is said, by its inventor, to be an illustration of the principles on which a perpetual movement may be effected, and the causes of that movement in the machine are pointed out by him, in the figure and connexions of the parts which compose it. For my disbelief in the agency of this machine, I am required to prove that no motion can result from that figure or connexion of parts, or that the causes assigned, are not adequate to the effects produced. But though it be granted I may disprove the agency of the alledged causes; it may be answered, that the inventor himself has mistaken the principle, and is unacquainted with the true cause, It will be shown presently, that a belief in the agency of these assigned causes, betrays an utter ignorance of the establish ed laws of motion: and if I would seek a man, who, from the practical application of these laws, should be thoroughly ac quainted with them, it would be one, who, during eleven years, had made them the subject of every variety of experiment. If the inventor be ignorant of the cause, then the invention is a mere accident. But I am told, that the machine has undergone many alterations, and that it is still to be improved by the ingenuity of the artist. Now, throwing out of the question the useless power of ingenuity, in a work that is said to be the offspring of chance; we will suppose the machine to have appeared in the progress of its construction, in twelve different forms; an allowance small enough, when he says he is constantly adding or altering something. But after so many ingenious endeavours, by so many indefatigable mechanics, who have, for so many ages, laboured in vain to form one machine to give a perpetual movement; that this movement should result from the accidental combination of materials, by one man, for twelve successive instances, in the short space of six months, is a wonder that has no parallel in the greatest miracle in the occurrence of chances. It is also urged by the believers in the efficiency of this machine, that we are often obliged to acknowledge the effect, though the principles that produce it is unknown. This is true, and the very instrument before us is a proof of the assertion, for we see the wheels move, but cannot tell why they move. Upon consideration, however, this will be found true, only of those effects, whose causes are removed beyond the scrutiny of our senses. Thus, it is true of most of the operations of nature, and of those tricks of legerdemain, where concealment, or velocity, or intricacy of motion bids defiance to investigation. Most of the agencies of nature that take place in the world, are the consequences of the action of matter that is too minute for the cognizance of our senses, of consequence, the principle, or in other words, the mode of acting of this matter which produces the effect, cannot be known. The case is different with the works of art; what one man can handle, to make, another man may see, and where the matter is seen, the principle by which it operates, or in other words, the mode in which one part acts on another, to produce an effect, may be known. In any complicated system of machinery, the laws resulting from the application of power, and from the communication of motion, are ascertained, because the parts operating are so palpable as to admit of their being made the subject of measurement and calculation. This is so much the case, that machinery is always planned before it is constructed. To apply these remarks to the movement in question. There is no sensible or acting quality in the parts of this machine that is not known. The principles on which the chain, the weights, the inclined planes, the levers of different lengths, the wheels of different diameters and positions, can act, are known, and may be made as much the subject of visible demonstration, as the estimate of weight by a steelyard, or the measure of a surface by a rule. I am told there is no secret part operating in this machine; the motion is said to be produced by the visible parts alone. It is with them I am engaged, and I will endeavour to prove that no visible part has any agency in the effect, except in communicating a motion that is derived from some other source. I address myself to those who have seen the machine, and who are acquainted with some of the elements of mathematics and mechanics. I propose to consider the various parts of the machine, and all the causes of its motion, that can be plausibly imagined; but I will previously lay down two propositions, to which reference will be made in the subsequent pages. Proposition First.-In any leaver, the greatest force is exerted at a right angle to the arm of that lever, for in this case there is less pressure on the fulcrum. Let CA be a lever, C B D A and let a force applied at A, act in the direction A D. EThe force A D being re solved into A B and B D, A B will represent the force |