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Preface.

S?ren Hjorth:

Childhood and Youth 1

The Railway 4

Electricity 7

Hard Times 18

Sources 29

S?REN HJORTH.

Childhood and Youth.

S?ren Hjorth was born on the 13th of October, 1801. He spent his childhood at Vesterbygaard, an estate rented by his father, Jens Hjorth, in Jordl?se Parish, north of Tiss?. His mother's maiden name was Margrethe Lassen. Of their numerous children only two, besides S?ren, survived childhood.

The parents became early aware that their son possessed great mechanical genius. He received his first education from the parish school-master. After Hjorth was confirmed, his father leased the beautiful estate Dragsholm, in Odsherred County, where he remained for many years, and after the death of his first wife, he married baroness Zytphen-Adeler.

Though he did not have an opportunity of learning much in his childhood, Hjorth succeeded in his youth in passing an examination which admitted him to the Bar. Later on he became the steward of Bonderup Estate, near Kors?r, but in this position he did not feel satisfied, and in 1828 he became a volunteer in the State Treasury, in Copenhagen. In 1836, he advanced to the position of Clerk of the Exchequer and secretary. Although Hjorth's occupation, during the last 30 years of his life, was mainly that of a civil engineer, he always continued to be addressed as Secretary Hjorth, and by this title he is still remembered by some of his surviving contemporaries.

Hjorth's interests while at the Treasury were not concentrated solely on his work there. Mechanical problems always fascinated him. It is told that, during this period, he made all kinds of experiments at Dragsholm, and, among other things, he constructed a thrashing-machine. In 1832 he constructed a rotary steam-engine, which was made by Schi?dt, a mechanic residing at St. Annae Plads, and, upon Hjorth's application, it was bought by the King for 500 rixdollars in notes. The King donated it to the newly founded Polytechnic Institute, this being the place where it might best be utilized and >>where this original domestic invention might most suitably be placed<<. The same year, Hjorth described in >>Ursin's Magazines for Artists and Artisans<< a steam-car, invented by him and adapted to be propelled by means of the rotary steam-engine. So Hjorth once more made a petition to the Government for a subvention of 2000 to 2500 rixdollars to assist in the practical manufacture of this car. The decision on this application was postponed, however, at the suggestion of Professors ?rsted, Zeiss and Forchhammer, because Hjorth had not yet finished the installation of the boiler for the first steam-engine at the Polytechnic Institute. Hjorth did not succeed in making the engine work, as it was not made with sufficient accuracy. The sum for which the car was to be made, was never granted, as petitioned for, although Hjorth had given up using his rotary engine for it; and the car itself was probably never built.

At that time, the use of steam-cars on the country roads attracted great attention in England, and many different constructions appeared. In 1834 Hjorth, aided by subventions from the >>Rejersen Foundation<< and the Government, went to England, in order to acquaint himself with the use of these steam-cars on high-roads and railroads. During these years he very actively investigated the use of steam-power, especially as a means of propulsion for vehicles and ships. With admirable interest and diligence he studied the steam propelled road-carriage, and for a long time he considered that to be the future means of conveyance. Although he did not succeed in getting his own steam-carriage put to practical use, he made many experiments on a steam car, and I am told by one of his passengers that on the level streets of Copenhagen and Frederiksberg all went very well, but the carriage could not climb Valby hill.

During these years, Hjorth also attended the lectures at the Polytechnic Institute, and he was especially interested in ?rsted's lectures on the physics of the globe, and on electricity and magnetism.

Notwithstanding his unsuccessful experiments with the rotary steam-engine, Professors ?rsted, Zeiss and Forchhammer had to give him a warm recommendation, when he made a petition to the Ministry in order to get his expenses refunded by the Government. They mentioned his indefatigable zeal, his great diligence, and the considerable expense borne by him in the pursuit of his researches. The numerous and expensive experiments absorbed all the money Hjorth could procure: not only his salary was spent, but also such funds as he was able to raise among his friends.

The Railway.

After his return to Denmark, he spent some years as manager of Marschall's piano factory, though still at work with his railroad schemes, and in 1840 he happened to find a man named Schram, a book-keeper, who shared his interests and was able to assist him in the realisation of his ideas. In 1840, these two men published a detailed calculation of the probable revenues and expenses of a railroad between Copenhagen and Roskilde. This project, however, did not arouse any interest, and people were mostly inclined to smile at the idea, and it appeared impossible to induce competent men to take, any interest in the scheme, much less to invest money therein.

Then, in 1841, they applied to the young >>Industrial Association<< which body referred the case to its special committee of commerce. Even this committee did not seem much inclined to listen to Hjorth's and Schram's proposition, but their undefatigable energy finally succeeded in persuading the committee of commerce to convoke a large meeting to be held on the 24th of March. Here it was decided to make an application to the Government for the surveying of the proposed railroad line and, to the surprise of many, the petition was granted. Hjorth, possessing distinctive agitatory faculties, showed great activity, delivering lectures and exhibiting models, and tried thereby to excite interest in his schemes. His contemporaries describe him as a sociable man of a winning and lovable disposition and possessing a certain persuasive power. He was well liked by his friends as well as by his many casual acquaintances. In 1841 both Hjorth and Schram were elected members of the Board of Representatives of the Industrial Association, and from 1841 to 1843 Hjorth was the vice-president of the association. Now there began to be some sympathy for their cause, and the Board of Representatives of the Industrial Association showed a willingness to follow the sub-committee elected, consisting of the two motionists and Lector, Wilkens of the Polytechnic Institute. The strenuous efforts of this sub-committee resulted in the Industrial Association submitting, in January 1843, an application for a franchise to form a stock-company for the purpose of building a railroad from Copenhagen, by way of Roskilde, to a sea-port on the western coast of Sealand. This franchise, was granted, for a period of 100 years, and on the 16th of April 1844 the Industrial Association issued a public invitation to take stock in a company whose stock capital was to be 1-1/2 million rixdollars, a very considerable sum for those times. As early as in the beginning of May, most of the stock was taken--mainly in Hamburg. While the confidence in a scheme of this kind was but slight in Denmark, the speculation in railroad stocks was nearly culminating at the stock-exchanges of Germany and England; as a matter of fact, it became near being a swindle. The Sealand Railroad Company was founded on the 2nd of July 1844, and Hjorth became its first technical director, while Schram became its first general manager. The Industrial Association received 15000 rixdollars for the franchise, and from this sum it paid 3000 to Hjorth and Schram.

In 1843, Hjorth was unanimously elected president of the Industrial Association. In 1845, he had to resign this office, but as it appeared very difficult to concentrate the votes in favour of a new president and vice-president, >>Secretary Hjorth, to meet the general demand, accepted the vice-presidency<<, which office he then held for a year.

In the meantime, the railroad company had finished the construction of its first piece of road, from Copenhagen to Roskilde, and this was opened for traffic on the 27th of June 1847, some days before the time limit fixed. Even at that time it was decided, owing to Hjorth's influence, to extend the road to Kors?r. The cause of the delay in commencing this work was the railroad crisis which had just broken out in Germany and England, making it impossible to obtain money for the construction of railroads. This road, therefore, was not constructed until the government, in 1852, guaranteed an interest of 4% on the capital invested.

Hjorth retained his position for about 4 years, and concerning this period he writes: >>All the great difficulties and obstacles to be surmounted during the construction of the road influenced my health to such a degree that I broke down and was forced to abandon my position as technical director of the railroad before the expiration of my term of office, in order that I might take a water-cure at Klampenborg<<. After he had, to some extent, regained his health there, and another board of directors had been elected, he made a travel to England which turned out to be of such great importance that we will describe it more fully in the following.

Electricity.

After Faraday, in 1831, had discovered how an electric current might be produced by means of a magnet, many people busied themselves by trying to put this invention into practical use, and numerous attempts were made to construct electro-magnetic and magneto-electric machines for useful purposes.

No wonder that these efforts attracted Hjorth's attention, and, as early as 1842, he had drafted an electro-magnetic machine, consisting of a stationary circle of magnets, whose poles were directed against the poles of a moveable circle of magnets. In 1843 this sketch was deposited with the Royal Scientific Society, but the sketch itself, as well as the explanation belonging to it, are very incomplete.

In the month of April, 1848, Hjorth made a petition to the government for a subvention of 200 rixdollars, in order that he might go to England to get an electro-magnetic machine designed by him, made there. Hjorth had noticed that, in a piece of iron encircled by an electric current, the magnetism only to a certain extent would increase, with the strength of current, there being a point of saturation for the iron. When this point has been reached, it will be of no use to increase the intensity of the current, since the magnetism will not increase any further. On the basis of this observation, Hjorth had constructed his machine, but he had confided the details thereof only to Professors ?rsted and Forchhammer. In the report on Hjorth's petition made by these two professors to the Board of Trade, they, curiously enough, take exception to the above-mentioned observation by Hjorth, while its correctness will now be acknowledged by any electrician. These professors, however, advised that Hjorth's petition should be granted, using this liberal argument, worded by ?rsted: >>Regarding the petitioner's new electro-magnetic machine, we must state that we find it quite ingenious, and although we are not convinced that it will produce remarkable effects, we should consider it useful to have a working model executed. Having during so many years worked for this case, the petitioner might perhaps, by the execution of such a model, be enabled to make some further invention, which would bring him nearer to the goal. Indefatigable zeal has often accomplished its purpose, where science had to declare the means at first used, to be entirely inadequate, but where, by continued work, entirely different means, previously unknown to the inventor, were found. Inasmuch as the sum of 200 rixdollars asked for is so small, we find it advisable to grant the subvention. Still we cannot refrain from remarking that the petitioner's machine may just as well be made here as at any other place<<.

Thus the discoverer of electro-magnetism cleared the road which was to lead to the most beautiful application of electro-magnetism, that application which, before all others, has been of radically reforming importance during the last half century, thereby throwing double splendor on ?rsted's name.

The larger of the machines here referred to was shown in action to several technical experts, and created considerable sensation, especially on account of the great length of stroke attained--13-1/2 inches--and the uniform motion of the machine. The machine is mentioned in >>Mining Journal<<, for the 5th of May, and 16th of June 1849, and an extract of these articles is published in the >>Flyveposten<< for the 3rd of July the same year.

Hjorth was invited to show the machine at the Royal Society, and at the annual meeting of the Society of Civil Engineers, of which he was a member. It was exhibited at the Universal Exhibition in London, in 1851. In the catalogue it was highly commended, and it received the only prize-medal awarded to electrical machines.

So it appears that Hjorth, as early as on the 1st of May 1851, with perfect clearness, has pronounced the dynamo-electric principle.

Under the date of June 24th, 1851, we find sketched out another beautiful idea for the construction of a dynamo. It must be regretted that this machine has not been executed, as it would certainly have proved superior to his dynamo of 1855, which has many points in common with this project. Fig. 2 shows a reproduction of this page of the sketch-book. There is no descriptive text to this sketch, only at one side of the drawing, these very significant words are written: >>Magneto-Electric arrangement with mutual action<<. All the six powerful held magnets are of cast iron, and they are wound so as to be magnetized by the current, produced by the dynamo itself.

In November, 1851, Hjorth returned to Copenhagen, and here he continued what he had commenced in England. In May, 1852, he deposited with the >>Society of Sciences<< some papers, signed by Professors Scharling and Forchhammer in December, 1851. These papers contain two descriptions, written in English, and two drawings of >>dry batteries<<. These consist of 3 or 4 circular rows of vertical steel rod magnets, placed one above the other, and disposed round a vertical shaft, carrying 2 or 3 circular rows of armatures. Each armature consists of a piece of soft iron, and is wound with a strip of copper, in a special manner. There are, in each row, as many armatures as magnets. The hollow shaft, as well as the magnets, which are fitted with shoes of soft iron, are wound, and encircled by the current produced in the armatures. With regard to the magnetic arrangement, this machine comes very near to the one patented by Brett in 1848, and it will be noticed that it cannot be said to be constructed according to the dynamo principle, as the >>mutual<< action plays no important part, the magnets being permanent steel magnets, hardly adapted to receive much extra magnetism by the current of the machine. Hjorth points out, as the novel feature of these machines, the division of the steel magnets into many small ones, with an armature corresponding to each magnet. Hereby he claims, for the same weight of the steel magnets, a larger capacity of the machine than if he had used fewer, but larger steel magnets. The machine is fitted with a commutator for direct current.--In March, 1854, the sketch-book contains another sketch of a dynamo, with clear indication of the dynamo principle, approximately as it was patented on the 14th of October the same year. This sketch is reproduced in Fig. 3. The machine has two permanent cast iron magnets and two electro-magnets. The armature cores are fitted with oblique pole-shoes. The description is very brief and contains the same as the patent specification.

In 1853 Hjorth negotiated with a certain Dr. Watson, who had constructed a >>dry battery<< by means of which Hjorth had meant to drive his electro-magnetic machine. The object of their negotiations was to buy out Hjorth's above-named partners, and to form a new company for the purpose of exploiting the above-mentioned two machines. The partnership, however, was not realized, and in spring of 1854, Hjorth himself commenced to have a 3 HP battery built in Copenhagen. The machine was fitted with cast iron magnets, and in all probability it was similar to the project of March 1854, and agreed with the patent of October, the same year.

From the above-named sketch-book notations, and the patent specification, it will be seen that Hjorth, during the years 1851-54, has repeatedly pronounced the dynamo principle with perfect clearness, and that he has utilized it in several projects.

It is worth noting that Hjorth's so-called >>permanent<< magnets are of cast iron. This shows that Hjorth has known of remanence, or permanence. He has known that cast iron always possesses some slight magnetism, either induced by the earth magnetism or as a remnant--remnant magnetism--left over from its being magnetized in a coil. It has heretofore been assumed that Siemens was the first to call attention to this property of iron, in his paper in the transactions of the Royal Society, of the 14th of February, 1867.--Thus Hjorth used this weak remanent magnetism in the large cast iron magnets to produce the initial current in the dynamo, which then excites itself.--At the end of the patent specification, Hjorth points out that the remanent magnets may also be coiled , and thereby he comes closer to the later dynamo constructions.

FOOTNOTES:

According to the usual terminology of those times, an >>electro-magnetic<< machine means a machine driven by electricity, an electromotor, while, on the other hand, a >>magneto electric battery<<, or a >>dry battery<< is a machine for producing electricity.

Specification of Patent No. 12295, 1848.

This is correct, as long as he uses armatures with but a single winding, because, in that case, the number of armature windings is proportional to the number of steel magnets. Whereas Hjorth is mistaken, when in 1867 he makes the same statement about a machine, where nothing prevents the armature from being fitted with a great number of windings.

Specification of Patent No. 2198, 1854.

Specification of Patent No. 806, 1855.

Specification of Patent No. 2199, 1854.

Specifications of Patents No. 807 and 808, 1855.

Hard Times.

Though Hjorth was thus ship-wrecked on his favourite idea, he nevertheless discovered new land, fertile for coming generations. His intrepid zeal guided him, as ?rsted had anticipated, in spite of his lack of scientific education, on to the road leading to the splendid results of this day.

None of Hjorth's original partners participated in the manufacture of his latest machines, and possibly this was due to his above-mentioned erroneous idea. Only one of his English friends, Wm. Macredie, of Melbourne, maintained his attachment to Hjorth and his confidence in him to the last. He was always very interested in Hjorth's schemes, and, besides, he shared his religious creed.

Hjorth was very anxious as to his future. When he returned from England, he stood quite destitute and felt depressed by poverty. His health was not of the best, and his formerly so neat hand-writing had become unsteady. He received, shortly after his return, a communication from his English partners that they wished to have the dynamo patented in Denmark and France, which showed that they had faith in this machine, but nevertheless these were hard times for Hjorth.

The dynamo remained for some time with Malcolm, in Liverpool, and negotiations for its sale were several times entered into, but were without results. It was tested on several occasions, but these tests proved that it could not yield as much as might be expected from its size. The uncoiled magnets, which were originally of cast iron, were replaced by more powerful steel magnets. Upon the whole, this dynamo had a rather eventful existence, for first every other magnet pole was removed , and then it was proposed to rewind the magnets. In May, 1857, it was donated to the Polytechnic Institute, Regent Street, in London. Among the papers left by Hjorth, there are a daguerreotype and a photograph of this machine, .

Notwithstanding a thorough search of the London museums, it has been impossible to trace this machine, which is said to have been seen in London during the nineties.

Hjorth was now compelled to find a new means of earning his livelihood, and to make new connections. In 1857, he became the representative of Cyclop's Steel Manufactory, Charles Cammell, of Sheffield, and in 1859, he applied for and obtained a licence as a translator of English in Copenhagen. Finally he had a kind of engineering and patent office, assisting strangers in obtaining monopolies, and doing work for new railroads, bridges etc. In the beginning of the sixties he caused a research to be made concerning the use of coals from Hornholm and Silkeborg, and the use of peat for briquettes. In April, 1860, he applied to the government for a position, enabling him to work for the building of new railroads in Denmark, and at the same time he referred to his previous merits in that direction. As he had not, within a year thereafter, received any position, he made a petition for a yearly pension, in case such a position could not be given to him. As >>the idea of building the Sealand railroad, as well as the general location of this road, is mainly due to Secretary Hjorth ... and further more, no small share in the completion of the undertaking is due to him<<, it was proposed, on the budget for 1861-62, to grant a pension to Hjorth. That year and the following ones, until his death, he received 500 rixdollars.

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