Pantechnicon

“ The irreversible phenomena are much more difficult to bring into line; but they, too, are being co-ordinated and tend to come into the unity. The light which illuminates them comes from Carnot's principle. For a long time thermo-dynamics was confined to the study of the dilatations of bodies and of their change of state. For some time past it has been growing bolder, and has considerably extended its domain. We owe to it the theories of the voltaic cell and of their thermo-electric phenomena; there is not a corner in physics which it has not explored, and it has even attacked chemistry itself. ”

“ Whibble sat, luckily for himself, at a safe distance, regarding him. The four malefactors, feigning a profound absorption in their work, watched him furtively with the keenest interest. For even within the limits of the Three Gases, Plattner's practical chemistry was, I understand, temerarious.
They are practically unanimous in their account of Planner's proceedings. He poured a little of the green powder into a test-tube, and tried the substance with water, hydrochloric acid, nitric acid, and sulphuric acid in succession. ”

“ Penton smiled good-naturedly on the young man who was standing before him.
"Yes, sir, I have a plan by which I think you ought to be able to save your electric motors [176] considerably and at the same time make greater speed in getting ore to the chutes."
"If you have a practical plan for doing that you will have accomplished a great deal, young man. What is your plan?"
"Well, sir, it is an engineering problem. Not being an engineer, I perhaps shall not be able to overcome all the difficulties in the way. ”

“ Let us return, for an instant, to the experiment of the coloured rings developed on a surface of platina by means of the electro-chemical apparatus described in the beginning of this Memoir. The platina surface belongs to the positive pole of the pile, and the electro-negative elements of the solution (which in the present case are the oxygen of water and the acid of acetate of lead) are deposited at this pole. I will not undertake to say by what species of affinity or force it is that these elements are attracted to each other and spread out into thin films on the platina. ”

“ By inserting the positive electrode after the negative in a vessel of salt water, luminous and other effects were observed which were considered to have a strong resemblance to those of Auroræ.
M. Planté advocates the theory that the imperfect vacuum of the upper regions, acting like a large conductor, plays the part of the negative electrode in his experiments, while the positive electricity flows towards the planetary spaces, and not towards the ground, through the mists and ice-clouds which float above the Poles. ”

“ The appliances for the practical teaching of chemistry in the Sussexville Proprietary School, as in most small schools in this country, are characterised by a severe simplicity. They are kept in a small cupboard standing in a recess, and having about the same capacity as a common travelling trunk. Plattner, being bored with his passive superintendence, seems to have welcomed the intervention of Whibble with his green powder as an agreeable diversion, and, unlocking this cupboard, proceeded at once with his analytical experiments. ”

“ The researches of M. Gaston Planté on the polarization of voltameters led to his invention of the secondary cell, composed of two strips of lead immersed in acidulated water. These cells accumulate, and, so to speak, store up the electricity passed into them from some outside generator. When the two electrodes are connected with any source of electricity the surfaces of the two strips of lead undergo certain modifications. Thus, the positive pole retains oxygen and becomes covered with a thin coating of peroxide of lead, while the negative pole becomes reduced to a clean metallic state. ”

“ Similar investigations were pursued by many others, among whom Father G. B. Beccaria (1716–1781) deserves especial mention. John Canton (1718–1772) made the important contribution to knowledge that electricity of either sign could be produced on nearly any body by friction with appropriate substances, and that a rod of glass roughened on one half was excited negatively in the rough part and positively in the smooth part by friction with the same rubber. Canton first suggested the use of an amalgam of mercury and tin for use with glass cylinder electrical machines to improve their action. ”

“ However, there is another equally fatal objection to this theory, founded on experiment; to make which objection good, I will not merely adduce the result of my own, but that of certain experiments carried out at Paris, which place the matter beyond a doubt. In the Pantheon, at Paris, there is a pendulum of the length of 230 feet, by means of which experiments can be made under the most favourable conditions possible as regards suspension, exclusion of currents of air, &c. ”

“ Planté carefully studied the changes which occur in the formation, charge and discharge of the cell. In forming, he placed two sheets of lead in sulphuric acid, separating them by narrow strips of caoutchouc (fig. 1) . When a charging current is sent through the cell, the hydrogen liberated at one plate escapes, a small quantity possibly being spent in Planté’s cell.reducing the surface film of oxide generally found on lead. Some of the oxygen is always fixed on the other (positive) plate, forming a surface film of peroxide. ”

“ The patentees, in describing the invention, say that they 'have found from experience that lead and some of its alloys, when recently become set, or in a condition just short of fluidity, being still under heat and extreme pressure, in a close vessel, will reunite perfectly after a separation of its parts,' and that, therefore, they construct their machinery as follows-and then proceed to describe the machinery or apparatus, as adapted by them to this discovery, and by which they produce the practical result above stated. ”

“ It is remarkable that the assertion or hypothesis that electricity or magnetism is concerned in the production of the phenomena in question, has never yet had an origin in any high scientific authority. This is accounted for by the fact that those who are [79] properly acquainted with this agency, and who have the proper apparatus at their command, can demonstrate the truth or falsity of such a hypothesis with the greatest ease. For an experiment, place your Planchette upon a plate of glass, or some other non-conducting substance. ”

“ Pacinotti states that the reasons which induced him to construct the apparatus on the principle which we have just described, were: (1) That according to this system the electric current is continuously traversing the coils of the armature, and the machine is kept in motion not by a series of intermittent impulses succeeding one another with greater or less rapidity, but by a constantly acting force producing a more uniform effect. ”

“ Nay, even if the needle be placed upon the floor near the punch, its point upwards, the end of the punch, tho' so much higher than the needle, will not attract the scale and receive its fire, for the needle will get it and convey it away, before it comes nigh enough for the punch to act. And this is constantly observable in these experiments, that the greater quantity of electricity on the pasteboard tube, the farther it strikes or discharges its fire, and the point likewise will draw it off at a still greater distance. ”

“ One cannot, in fact, according to the principle of Carnot, transform it integrally into mechanical energy, since the heat possessed by a body can only yield work on condition that a part of it falls on a body with a lower temperature. ”

“ Matthey, and see them hammering and welding away, you would see the value of the experiment I am about to shew you. I have here some platinum-wire. This is a metal which resists the action of acids, resists oxidation by heat, and change of any sort; and which, therefore, I may heat in the atmosphere without any flux. I bend the wire so as to make the ends cross: these I make hot by means of the blowpipe, and then, by giving them a tap with a hammer, I shall make them into one piece. ”

“ I do not propose to limit myself to the specific machinery or parts of machinery described in the foregoing specification and claims; the essence of my invention being the use of the motive power of the electric or galvanic current, which I call electro-magnetism, however developed for marking or printing intelligible characters, signs, or letters, at any distances, being a new application of that power of which I claim to be the first inventor or discoverer.'
It is impossible to misunderstand the extent of this claim. ”

“ He wondered still if the vial he had put away on the upper shelf of the laboratory in the factory could possibly add some light to this problem.
Of two things he was certain: The dust-burning motor was a complete success and the blue steel was the most marvelous steel ever invented. He hoped that Pant and he would not now be long in revealing these facts to those most interested. They would delight the heart of their employer and would bring great joy to the aged inventor of the motor. ”

“ In the course of his experiments he found that a difference in the metals of which the arc was composed, when used for the purpose of eliciting the so-called animal electricity, made a great difference in the electrical phenomena observed and in the amount of muscle twitchings obtained. In one brilliant series of experiments, moreover, he showed that, even when the metallic portions touching nerve and muscle were identical, there might still be distinct electrical phenomena, if only an artificial difference in temperature of the end of the metallic arc were produced. ”

“ The A Battery Potentiometer.--This device is simply a resistance like the rheostat described in connection with the preceding vacuum tube receiving sets but it is wound to 200 or 300 ohms resistance as against 1-1/2 to 6 ohms of the rheostat. It is, however, used as well as the rheostat. With a vacuum tube detector, and especially with one having a gas-content, a potentiometer is very necessary as it is only by means of it that the potential of the plate of the detector can be accurately regulated. ”

“ Often the most varied methods are used in conjunction or alternately with a patience and persistence worthy of a more honourable cause, but practised with ever-greater keenness, alas, with the promise of much gain. Some of the most successful patinas are obtained not only by duly working at the colouring and oxidation of the metal, but by composing the alloy in such a way as to favour the production of a convincing patina later on. ”

“ This combination consists only of the application of a piece of rubber to one end of the same piece of wood which makes a lead-pencil. It is as if a patent should be granted for an article, or a manufacture as the patentee prefers to term it, consisting of a stick twelve inches long, on one end of which is an ordinary hammer, and on the other end is a screw-driver or a tack-drawer, or, what you will see in use in every retail shop, a lead-pencil, on one end of which is a steel pen. ”

“ This ingenious invention is productive of results similar to Edison’s electric pen. It is the invention of an American gentleman, Mr. J. W. Brickenridge, of Lafayette, Indiana. The illustration (fig. 483) explains the mechanism of the pneumatic pencil. The whole apparatus is figured on the left side of the picture, while the longitudinal section of the pencil is shown on the right, the small cut at the top being a vertical section of a portion of the motive power. Compressed air furnishes the power of pressure, which is accomplished by means of a perforating needle. ”

“ Every scientist knows that water can be burned by means of an electric current; but this method is too expensive. Olyphant was on the track of a much cheaper and simpler method, which had already yielded him astonishing results but was not yet sufficiently perfected for publication. I am bound to respect his wishes in giving no hint as to the nature of the discovery, which I do the more readily as he has never confided to me the details of his process. ”

“ For a long time no satisfactory results were obtained, but at last, in 1696, Papin at Marburg discovered the true solution—the condensation of steam in a cylinder fitted with a piston. The steam-engine was invented. Papin, an experimenter really worthy of respect, who attempted to solve the problem in the most various ways, and who has made a whole series of other remarkable inventions, is its true inventor. ”

“ The fixed pivot, pointer, and pencil must be rigid, and, with pivot c, be of such a length that the pantograph as a whole moves parallel to the paper. A little sliding weight to place on the rod near the pencil will be found useful for keeping the pencil point in constant contact with the paper.
If the apparatus works stiffly, ease the holes a trifle and lead-pencil the wood at all points where two surfaces rub. It is absolutely impossible to make a good reproduction with a stiff, jerky pantograph. ”

“ The tremendous heat generated during the boring processes—we may recall how Benjamin Thompson made water boil by the experimental boring of a cannon—is kept down by streams of soapy water continually pumped through and over the metal. We notice this flow of lubricating fluid in all directions, from oil dropping slowly on to the small brass-milling machines to this fountain-play of water which makes a pleasant undertone amidst the jangle of the machines. But these machines are less noisy than we anticipated; in their actual working they emit scarcely the slightest sound. ”