OTES

[1] The general scheme of a fire-alarm telegraph system embodies a central office to which notice can be sent from any number of signal boxes of the outbreak of a fire in the district covered by the box, the central office in turn calling out the nearest fire engines, and warning the fire department in general of the occurrence. Such fire alarms can be exchanged automatically, or by operators, and are sometimes associated with a large fire-alarm bell or whistle. Some boxes can be operated by the passing public; others need special keys. The box mechanism is usually of the ratchet, step-by-step movement, familiar in district messenger call-boxes.

[2] This I invented as well.--T. A. E.

[3] See illustration on opposite page, showing reproduction of the work done with this machine.

[4] The sand battery is now obsolete. In this type, the cell containing the elements was filled with sand, which was kept moist with an electrolyte.

[5] See Federal Reporter, vol. 109, p. 976 et seq.

[6] Briefly stated, the essential difference between Bell's telephone and Edison's is this: With the former the sound vibrations impinge upon a steel diaphragm arranged adjacent to the pole of a bar electromagnet, whereby the diaphragm acts as an armature, and by its vibrations induces very weak electric impulses in the magnetic coil. These impulses, according to Bell's theory, correspond in form to the sound-waves, and passing over the line energize the magnet coil at the receiving end, and by varying the magnetism cause the receiving diaphragm to be similarly vibrated to reproduce the sounds. A single apparatus is therefore used at each end, performing the double function of transmitter and receiver. With Edison's telephone a closed circuit is used on which is constantly flowing a battery current, and included in that circuit is a pair of electrodes, one or both of which is of carbon. These electrodes are always in contact with a certain initial pressure, so that current will be always flowing over the circuit. One of the electrodes is connected with the diaphragm on which the sound-waves impinge, and the vibration of this diaphragm causes the pressure between the electrodes to be correspondingly varied, and thereby effects a variation in the current, resulting in the production of impulses which actuate the receiving magnet. In other words, with Bell's telephone the sound-waves themselves generate the electric impulses, which are hence extremely faint. With the Edison telephone, the sound-waves actuate an electric valve, so to speak, and permit variations in a current of any desired strength.

A second distinction between the two telephones is this: With the Bell apparatus the very weak electric impulses generated by the vibration of the transmitting diaphragm pass over the entire line to the receiving end, and in consequence the permissible length of line is limited to a few miles under ideal conditions. With Edison's telephone the battery current does not flow on the main line, but passes through the primary circuit of an induction coil, by which corresponding impulses of enormously higher potential are sent out on the main line to the receiving end. In consequence, the line may be hundreds of miles in length. No modern telephone system in use to-day lacks these characteristic features--the varying resistance and the induction coil.

[7] As an illustration of the perplexing nature of expert evidence in patent cases, the reader will probably be interested in perusing the following extracts from the opinion of Judge Dayton, in the suit of Bryce Bros. Co. vs. Seneca Glass Co., tried in the United States Circuit Court, Northern District of West Virginia, reported in The Federal Reporter, 140, page 161:

"On this subject of the validity of this patent, a vast amount of conflicting, technical, perplexing, and almost hypercritical discussion and opinion has been indulged, both in the testimony and in the able and exhaustive arguments and briefs of counsel. Expert Osborn for defendant, after setting forth minutely his superior qualifications mechanical education, and great experience, takes up in detail the patent claims, and shows to his own entire satisfaction that none of them are new; that all of them have been applied, under one form or another, in some twenty- two previous patents, and in two other machines, not patented, to-wit, the Central Glass and Kuny Kahbel ones; that the whole machine is only `an aggregation of well-known mechanical elements that any skilled designer would bring to his use in the construction of such a machine.' This certainly, under ordinary conditions, would settle the matter beyond peradventure; for this witness is a very wise and learned man in these things, and very positive. But expert Clarke appears for the plaintiff, and after setting forth just as minutely his superior qualifications, mechanical education, and great experience, which appear fully equal in all respects to those of expert Osborn, proceeds to take up in detail the patent claims, and shows to his entire satisfaction that all, with possibly one exception, are new, show inventive genius, and distinct advances upon the prior art. In the most lucid, and even fascinating, way he discusses all the parts of this machine, compares it with the others, draws distinctions, points out the merits of the one in controversy and the defects of all the others, considers the twenty-odd patents referred to by Osborn, and in the politest, but neatest, manner imaginable shows that expert Osborn did not know what he was talking about, and sums the whole matter up by declaring this `invention of Mr. Schrader's, as embodied in the patent in suit, a radical and wide departure, from the Kahbel machine' (admitted on all sides to be nearest prior approach to it), `a distinct and important advance in the art of engraving glassware, and generally a machine for this purpose which has involved the exercise of the inventive faculty in the highest degree.'

"Thus a more radical and irreconcilable disagreement between experts touching the same thing could hardly be found. So it is with the testimony. If we take that for the defendant, the Central Glass Company machine, and especially the Kuny Kahbel machine, built and operated years before this patent issued, and not patented, are just as good, just as effective and practical, as this one, and capable of turning out just as perfect work and as great a variety of it. On the other hand, if we take that produced by the plaintiff, we are driven to the conclusion that these prior machines, the product of the same mind, were only progressive steps forward from utter darkness, so to speak, into full inventive sunlight, which made clear to him the solution of the problem in this patented machine. The shortcomings of the earlier machines are minutely set forth, and the witnesses for the plaintiff are clear that they are neither practical nor profitable.

"But this is not all of the trouble that confronts us in this case. Counsel of both sides, with an indomitable courage that must command admiration, a courage that has led them to a vast amount of study, investigation, and thought, that in fact has made them all experts, have dissected this record of 356 closely printed pages, applied all mechanical principles and laws to the facts as they see them, and, besides, have ransacked the law- books and cited an enormous number of cases, more or less in point, as illustration of their respective contentions. The courts find nothing more difficult than to apply an abstract principle to all classes of cases that may arise. The facts in each case so frequently create an exception to the general rule that such rule must be honored rather in its breach than in its observance. Therefore, after a careful examination of these cases, it is no criticism of the courts to say that both sides have found abundant and about an equal amount of authority to sustain their respective contentions, and, as a result, counsel have submitted, in briefs, a sum total of 225 closely printed pages, in which they have clearly, yet, almost to a mathematical certainty, demonstrated on the one side that this Schrader machine is new and patentable, and on the other that it is old and not so. Under these circumstances, it would be unnecessary labor and a fruitless task for me to enter into any further technical discussion of the mechanical problems involved, for the purpose of seeking to convince either side of its error. In cases of such perplexity as this generally some incidents appear that speak more unerringly than do the tongues of the witnesses, and to some of these I purpose to now refer."

[8] As a practical illustration of these facts it was calculated by Professor Barker, of the University of Pennsylvania (after Edison had invented the incandescent lamp), that if it should cost $100,000 for copper conductors to supply current to Edison lamps in a given area, it would cost about $200,000,000 for copper conductors for lighting the same area by lamps of the earlier experimenters --such, for instance, as the lamp invented by Konn in 1875. This enormous difference would be accounted for by the fact that Edison's lamp was one having a high resistance and relatively small radiating surface, while Konn's lamp was one having a very low resistance and large radiating surface.

[9] The following extract from Walker on Patents (4th edition) will probably be of interest to the reader:

"Sec. 31a. A meritorious exception, to the rule of the last section, is involved in the adjudicated validity of the Edison incandescent-light patent. The carbon filament, which constitutes the only new part of the combination of the second claim of that patent, differs from the earlier carbon burners of Sawyer and Man, only in having a diameter of one-sixty-fourth of an inch or less, whereas the burners of Sawyer and Man had a diameter of one-thirty-second of an inch or more. But that reduction of one-half in diameter increased the resistance of the burner FOURFOLD, and reduced its radiating surface TWOFOLD, and thus increased eightfold, its ratio of resistance to radiating surface. That eightfold increase of proportion enabled the resistance of the conductor of electricity from the generator to the burner to be increased eightfold, without any increase of percentage of loss of energy in that conductor, or decrease of percentage of development of heat in the burner; and thus enabled the area of the cross-section of that conductor to be reduced eightfold, and thus to be made with one-eighth of the amount of copper or other metal, which would be required if the reduction of diameter of the burner from one-thirty-second to one-sixty- fourth of an inch had not been made. And that great reduction in the size and cost of conductors, involved also a great difference in the composition of the electric energy employed in the system; that difference consisting in generating the necessary amount of electrical energy with comparatively high electromotive force, and comparatively low current, instead of contrariwise. For this reason, the use of carbon filaments, one-sixty-fourth of an inch in diameter or less, instead of carbon burners one-thirty-second of an inch in diameter or more, not only worked an enormous economy in conductors, but also necessitated a great change in generators, and did both according to a philosophy, which Edison was the first to know, and which is stated in this paragraph in its simplest form and aspect, and which lies at the foundation of the incandescent electric lighting of the world."

[10] For further explanation of "Feeder" patent, see Appendix.

[11] For description of feeder patent see Appendix.

[12] We quote the following interesting notes of Mr. Charles L. Clarke on the question of see-sawing, or "hunting," as it was afterward termed:

"In the Holborn Viaduct station the difficulty of `hunting' was not experienced. At the time the `Jumbos' were first operated in multiple arc, April 8, 1882, one machine was driven by a Porter-Allen engine, and the other by an Armington & Sims engine, and both machines were on a solid foundation. At the station at Milan, Italy, the first `Jumbos' operated in multiple arc were driven by Porter-Allen engines, and dash-pots were applied to the governors. These machines were also upon a solid foundation, and no trouble was experienced".

"At the Pearl Street station, however, the machines were sup- ported upon long iron floor-beams, and at the high speed of 350 revolutions per minute, considerable vertical vibration was given to the engines. And the writer is inclined to the opinion that this vibration, acting in the same direction as the action of gravitation, which was one of the two controlling forces in the operation of the Porter-Allen governor, was the primary cause of the `hunting.' In the Armington & Sims engine the controlling forces in the operation of the governor were the centrifugal force of revolving weights, and the opposing force of compressed springs, and neither the action of gravitation nor the vertical vibrations of the engine could have any sensible effect upon the governor."

[13] For technical description and illustration of this invention, see Appendix.

[14] By reason of the experience gained at this station through the use of these crude plug-switches, Mr. Edison started a competition among a few of his assistants to devise something better. The result was the invention of a "breakdown" switch by Mr. W. S. Andrews, which was accepted by Mr. Edison as the best of the devices suggested, and was developed and used for a great many years afterward.

[15] See 61 Fed. Rep. 655.

[16] For a proper understanding and full appreciation of the importance of fine grinding, it may be explained that Portland cement (as manufactured in the Lehigh Valley) is made from what is commonly spoken of as "cement rock," with the addition of sufficient limestone to give the necessary amount of lime. The rock is broken down and then ground to a fineness of 80 to 90 per cent. through a 200-mesh screen. This ground material passes through kilns and comes out in "clinker." This is ground and that part of this finely ground clinker that will pass a 200- mesh screen is cement; the residue is still clinker. These coarse particles, or clinkers, absorb water very slowly, are practically inert, and have very feeble cementing properties. The residue on a 200-mesh screen is useless.

[17] Broadly described in outline, the system consisted of an induction circuit obtained by laying strips of tin along the top or roof of a railway car, and the installation of a special telegraph line running parallel with the track and strung on poles of only medium height. The train and also each signalling station were equipped with regulation telegraphic apparatus, such as battery, key, relay, and sounder, together with induction-coil and condenser. In addition, there was a transmitting device in the shape of a musical reed, or buzzer. In practice, this buzzer was continuously operated at high speed by a battery. Its vibrations were broken by means of a key into long and short periods, representing Morse characters, which were transmitted inductively from the train circuit to the pole line, or vice versa, and received by the operator at the other end through a high-resistance telephone receiver inserted in the secondary circuit of the induction-coil.

[18] Edison received some stock from the parent lighting company, but as the capital stock of that company was increased from time to time, his proportion grew smaller, and he ultimately used it to obtain ready money with which to create and finance the various "shops" in which were manufactured the various items of electric- lighting apparatus necessary to exploit his system. Besides, he was obliged to raise additional large sums of money from other sources for this purpose. He thus became a manufacturer with capital raised by himself, and the stock that he received later, on the formation of the General Electric Company, was not for his electric-light patents, but was in payment for his manufacturing establishments, which had then grown to be of great commercial importance.

[19] It may be of interest to the reader to note some parts of the globe to which shipments of phonographs and records are made:

[20] A most remarkable instance of contemporaneous invention and without a parallel in the annals of the United States Patent Office, occurred when, on the same day, February 15, 1876, two separate descriptions were filed in that office, one a complete application and the other a caveat, but each covering an invention for "transmitting vocal sounds telegraphically." The application was made by Alexander Graham Bell, of Salem, Massachusetts, and the caveat by Elisha Gray, of Chicago, Illinois. On examination of the two papers it was found that both of them covered practically the same ground, hence, as only one patent could be granted, it became necessary to ascertain the precise hour at which the documents were respectively filed, and put the parties in interference. This was done, with the result that the patent was ultimately awarded to Bell.

[21] A notable instance of the fleecing of unsuspecting and credulous persons occurred in the early eighties, during the furor occasioned by the introduction of Mr. Edison's electric-light system. A corporation claiming to have a self-generating dynamo (practically perpetual motion) advertised its preposterous claims extensively, and actually succeeded in selling a large amount of stock, which, of course, proved to be absolutely worthless.

[22] The argument on appeal was conducted with the dignity and decorum that characterize such a proceeding in that court. There is usually little that savors of humor in the ordinary conduct of a case of this kind, but in the present instance a pertinent story was related by Mr. Lowrey, and it is now reproduced. In the course of his address to the court, Mr. Lowrey said:

"I have to mention the name of one expert whose testimony will, I believe, be found as accurate, as sincere, as straightforward as if it were the preaching of the gospel. I do it with great pleasure, and I ask you to read the testimony of Charles L. Clarke along with that of Thomas A. Edison. He had rather a hard row to hoe. He is a young gentleman; he is a very well-instructed man in his profession; he is not what I have called in the argument below an expert in the art of testifying, like some of the others, he has not yet become expert; what he may descend to later cannot be known; he entered upon his first experience, I think, with my brother Duncan, who is no trifler when he comes to deal with these questions, and for several months Mr. Clarke was pursued up and down, over a range of suggestions of what he would have thought if he had thought something else had been said at some time when something else was not said."

Mr. Duncan--"I got three pages a day out of him, too."

Mr. Lowrey--"Well, it was a good result. It always recalled to me what I venture now, since my friend breaks in upon me in this rude manner, to tell the court as well illustrative of what happened there. It is the story of the pickerel and the roach. My friend, Professor Von Reisenberg, of the University of Ghent, pursued a series of investigations into the capacity of various animals to receive ideas. Among the rest he put a pickerel into a tank containing water, and separated across its middle by a transparent glass plate, and on the other side he put a red roach. Now your Honors both know how a pickerel loves a red roach, and I have no doubt you will remember that he is a fish of a very low forehead and an unlimited appetite. When this pickerel saw the red roach through the glass, he made one of those awful dashes which is usually the ruin of whatever stands in its-way; but he didn't reach the red roach. He received an impression, doubtless. It was not sufficient, however, to discourage him, and he immediately tried again, and he continued to try for three- quarters of an hour. At the end of three-quarters of an hour he seemed a little shaken and discouraged, and stopped, and the red roach was taken out for that day and the pickerel left. On the succeeding day the red roach was restored, and the pickerel had forgotten the impressions of the first day, and he repeated this again. At the end of the second day the roach was taken out. This was continued, not through so long a period as the effort to take my friend Clarke and devour him, but for a period of about three weeks. At the end of the three weeks, the time during which the pickerel persisted each day had been shortened and shortened, until it was at last discovered that he didn't try at all. The plate glass was then removed, and the pickerel and the red roach sailed around together in perfect peace ever afterward. The pickerel doubtless attributed to the roach all this shaking, the rebuff which he had received. And that is about the condition in which my brother Duncan and my friend Clarke were at the end of this examination."

Mr. Duncan--"I notice on the redirect that Mr. Clarke changed his color."

Mr. Lowrey--"Well, perhaps he was a different kind of a roach then; but you didn't succeed in taking him.

"I beg your Honors to read the testimony of Mr. Clarke in the light of the anecdote of the pickerel and the roach."

[23] Afterward issued as Patent No. 162,633, April 27, 1875.

[24] Many of the illustrations in this article are reproduced from American Telegraphy and Encyclopedia of the Telegraph, by William Maver, Jr., by permission of Maver Publishing Company, New York.

[25] During the period in which Edison exhibited his lighting system at the Paris Exposition in 1881, his representative, Mr. Charles Batchelor, repeated Edison's remarkable experiments of the winter of 1875 for the benefit of a great number of European savants, using with other apparatus the original "dark box" with micrometer adjustment.

[26] The dark box had micrometer screws for delicate adjustment of the carbon points, and was thereafter largely used in this series of investigations for better study of the spark. When Mr. Edison's experiments were repeated by Mr. Batchelor, who represented him at the Paris Exposition of 1881, the dark box was employed for a similar purpose.

[27] The commercial manufacture of built-up sheets of mica for electrical purposes was first established at the Edison Machine Works, Goerck Street, New York, in 1881.

[28] Had Edison in Upton's Scientific American article in 1879 proposed such an exceedingly low armature resistance for this immense generator (although its ratio was proportionate to the original machine), his critics might probably have been sufficiently indignant as to be unable to express themselves coherently.

[29] M. Fontaine, in his book on Electric Lighting (1877), showed that with the current of a battery composed of sixteen elements, one lamp gave an illumination equal to 54 burners; whereas two similar lamps, if introduced in parallel or multiple arc, gave the light of only 6 1/2 burners in all; three lamps of only 2 burners in all; four lamps of only 3/4 of one burner, and five lamps of 1/4 of a burner.

[30] Not 491,993, issued February 21, 1893; No. 493,426, issued March 14, 1893; No. 772,647, issued October 18, 1904.

[31] The faces of these rolls were smooth, but as three-high rolls came into use later in Edison's Portland cement operations the faces were corrugated so as to fit into each other, gear-fashion, to provide for a high rate of feed.