The two rooms facing Noerregade formed the lecture-room , the scene of the discovery ; the others were preparation rooms .sx It has been possible to locate approximately the point in space , in Telephone House , where the original experiment was performed .sx In 1824 , Oersted departed from Noerregade 34 , and occupied a Professor's house ( Fig. 3 ) , belonging to the University at Studienstraede 6 .sx In 1829 , he founded the Polytechnic School and allowed some of the rooms of his own house to be used by that institution .sx At that time there was a courtyard separating his house from a private building , afterwards requisitioned by the University ( Fig. 4) .sx In 1890 , for the centralization of studies in Physico-Chemistry , Inorganic Chemistry , and certain branches of Mathematics , all the polytechnic schools were transferred to a new building in Soelvgade .sx On the day of his discovery , when he had assembled the apparatus , a lecture prevented him from trying what he had in mind .sx At the close of the lecture , he asked his class whether they would like to observe what might happen .sx The class remained and witnessed the result - a deflection of the compass-needle ( Fig. 5 ) , when there was an electric current in a neighbouring wire , placed in proper relation to the needle .sx The movement was so small that Oersted was inclined at first to attribute it to capricious disturbances .sx Moreover , he was perplexed because he could not account for the fact that the movement of the .sx poles of the pivoted magnet , in a horizontal plane , was at right angles to the direction of the current in the wire .sx Why was not the line of action of the magnetism the same as that of the originating electric current ?sx Later , he returned to the investigation ; he now used a much larger battery - copper-zinc , sulphuric acid - and he obtained a decided deflection of the needle .sx His procedure was thus in accordance with the most cherished methods and traditions of the pioneers :sx to his imagination he gave scope enough to inspire him with a definite object of research , by experiment he sought in the direction of that object for new facts , and , lastly , when a clue appeared , he extended the research in each direction , towards weakness and towards strength , far beyond the limits required for a class demonstration of the phenomena .sx In other investigations he studied especially the constitution and properties of water , and he developed for this research a new instrument ( Fig. 6 ) for measuring the compression of liquids .sx Later he examined the pressure-volume law for air , and other substances , and he carried the pressure to the limits of the apparatus then existing .sx Further , he investigated the derivation of aluminium from clay , and a new method of preparing oxides of chlorine .sx A third State-aided tour , in 1822-23 , took him to England , France and Germany .sx On that occasion he had an opportunity to observe especially the progress of investigations with regard to light , and he replenished the laboratory at Copenhagen with a number of instruments .sx On his homeward journey he established the " Society for the Distribution of Teaching Natural " .sx In 1828 he visited Norway and Berlin , where he addressed the physicists ; and in 1830 he made a similar visit to Hamburg .sx He next appears in 1834 , discussing questions of physics at Gottingen with Gauss , whom he had met at Altona in 1827 .sx From him he heard of the latest observations in magnetism , and of the new methods of measurement that Gauss had introduced .sx This concerned Oersted , for he had in mind the establishment of a magnetic observatory at Copenhagen .sx A few years later , he again went to Scandinavia , where he discoursed uponsubjects in a plane beyond the conventional circle of natural philosophy - he lectured upon the relation of physics to beauty , somewhat in accordance with Leibnitz's hypothesis of harmony and unity between the laws of nature and the laws of reason .sx His study of Danish literature never ceased .sx Into political affairs he entered boldly , and he made frequent communications to newspapers and journals , pleading for freedom of the press and for the advance of generous ideas in government .sx At .sx the other extreme , he went so far as to write in 1836 a great lyric-didactic poem entitled , " The Air " .sx It will suffice here to quote briefly from L. and J. B. Horner's English translation :sx Oersted , however , was not the first to derive poetic inspiration from the advance that was being made in aeronautics .sx The subject had long engaged the attention and had fired the imagination of men in the front rank of natural science .sx Twenty years earlier , Sir George Cayley had contributed a valuable article to the Philosophical Magazine ( vol. 47 , No .sx 214 , February 1816 ) on aeronautics , and had concluded with a verse , at once stirring and prophetic , by Dr. Darwin :sx Behold Oersted now , Secretary of the Konigl .sx Gesellschaft der Wissenschaften ; Professor Ordinarius at Copenhagen ; Corresponding Member of the Science Academie of the French Institut ; Director of the Polytechnic School of Copenhagen,which through his personal influence with Friedrich VI .sx he personally had called into existence ; Knight of the Ehrenlegion ( 1837 ) ; Conferenzrat ( 1840 ) ; Knight of the Prussian Order pour le merite in the Sciences and Arts ( 1842 ) ; possessor of the honorary diploma of Erlangen as Doctor of Medicine ( 1842 ) , and of the Grand Cross of Dannebrog ( 1847) .sx These dignities , however , did not prevent him from extending his studies , his sympathies , and his beneficent influence .sx To appreciate the scope and character of the man and his achievements , it is necessary to recall the turbulent age and circumstances in which he lived .sx His boyhood was marked by the war of 1789 , between Denmark and Sweden , by the struggle against serfdom in his country , and by a general movement towards political freedom .sx In the subsequent wars , Denmark threatened by Napoleon entered a league that brought her into conflict with England .sx In 1805 , Napoleon overthrew Austria and Russia at Austerlitz , and formed the Confederation of the Rhine under the protection of France .sx This was followed in 1806 by the abdication of the Emperor Francis II .sx , an event that marked the end of the Holy Roman Empire .sx The ultimate result was that when , in 1814 , the Napoleonic Empire began to fall to pieces , Denmark lost possession of Norway , and suffered impoverishment and distress , followed by an interval of agitation for a free constitution an agitation that in various phases disturbed the country to the day of Oersted's death .sx To comprehend where Oersted stands in the world's history , therefore , it is essential to realize the perilous position of his country at several periods during his long life .sx The main trouble began in 1780 , when Denmark declared the Baltic to be closed to the armed vessels of belligerent Powers .sx At that time England was at war with the American Colonies , and also with France and with Spain .sx Holland , Denmark , and the whole Baltic sought nevertheless to trade with England's enemies , in timber , tar , hemp , cordage , and provisions .sx England accordingly used armed vessels to search merchantmen .sx The Dutch held that a neutral flag should exempt from seizure .sx England replied by attacking the Dutch .sx Russia assisted merchantmen bound for French ports .sx Sweden and Denmark formed an .sx alliance to protect their trade .sx Denmark meanwhile kept in close touch with Russia , and , on December 7 , 1800 , Bonaparte joined the Russian league and devised a plan to invade India .sx His first move in this direction , however , was towards the commercial exclusion of English commerce from the continent of Europe .sx England hit back by placing an embargo on Russian , Danish , and Swedish ships in British ports , and at the same time she fitted out a fleet for the Baltic .sx Denmark , supported by France , followed by placing an embargo on all British ships in her ports ; she entered Hamburg and closed the Elbe to the English , she took possession of Lubeck and , aided by Prussian troops , the combined forces closed the Weser and the Ems to English vessels .sx In the early spring , England restored the balance by sending her fleet through the Sound , and by attacking Copenhagen .sx This fleet was under the command of Sir Hyde Parker , with Vice-Admiral Nelson as second in command .sx Parker did not excel , but Nelson , with his accustomed skill and zeal , accomplished the task .sx Parker held himself in reserve with many of his ships and , thinking that Nelson would suffer a reverse , made the signal, .sx " Discontinue the " .sx It was then that the famous incident occurred in which Nelson turned his blind eye to the telescope and hoisted his own battle signal , " Engage more " .sx Copenhagen collapsed ; Russia also gave in to England , but France did not .sx The next event that closely concerned Oersted was in 1807 .sx Bonaparte insisted that Denmark , Sweden , and Portugal should be compelled by France and Russia to enter into war against England .sx His object was to add the navies of Denmark , Sweden , and Portugal about forty ships of the line to his forces .sx For England it was a matter of life or death , and her immediate counter blow was to seize the Danish fleet .sx Admiral Gambia sailed from England on July 26 , 1807 , with forty-two fighting ships , and also with twenty-seven thousand troops under Lord Cathcart .sx Zealand was blockaded , Copenhagen was bombarded from September 2 until September 5 of that year , and the entire Danish fleet of eighteen sail of the line , ten frigates , and forty-two smaller vessels were forced to surrender .sx A great misfortune fell upon H. C. Oersted in 1813 when his brother , Niels Randulph Oersted , who was an officer in the Russian army , was killed at the battle of Leipsic .sx The troubles of his country pursued the great philosopher to the end , for in 1848 Germany was seeking to annex part of Denmark , and the Danish army absorbed much-needed wealth .sx It is noteworthy that in France , in 1848 , Arago was Ministre de la Guerre et de la Marine , and that Oersted , counting upon their friendship in the field of science , tried through him to influence French opinion concerning Slesvig in favour of Denmark , but without success .sx It is necessary next to glance at the state of electrical knowledge as Oersted found it , and as he left it .sx That lightning , from a distance , could reverse the poles of a magnet , and that an electric discharge from a Leyden jar would have the same effect , was familiar to him .sx Benjamin Franklin , in 1749 , had used these facts as an argument in proof of the identity of lightning and electricity ; and " the magneticalness of lightning " had been referred to in 1756 , in a history of the Royal Society .sx Similarly , that there was possibly an analogy between electricity and magnetism had long been a suggestion amongst physicists ; for in 1767 , Jan Hendrik Van Swinden , of Amsterdam , had discussed it in a prize essay and had decided that there is no definite analogy .sx There must be recalled also the circumstance that , in 1802 , Adam Walker published A System of Familiar Philosophy relating to the identity of light , heat , and electricity as modifications of a single agency , and that he declared that , " we have infinite data in favour of an electromagnetic " .sx Hence , it is not surprising that Oersted's discovery was , at first , imperfectly understood , and that there were critics who suggested that it had been anticipated .sx Earlier , he had himself vainly endeavoured with Ritter to trace an action between electricity and magnetism .sx Particulars of this investigation are to be found in the correspondence between the two physicists .sx To establish the priority of Oersted , it remains only to clear the issue in respect to results obtained by the Italian lawyer and mathematician Romagnosi .sx The case in favour of Oersted , in this instance , was established definitely by his countrymen , .sx Absalon Larsen , K. Prytz , and M. C. Harding .sx To elucidate the matter , it was desirable to dispose of the accounts of Romagnosi's results as given by Professor Giovanni Aldini in his Essai , published in 1804 .sx At page 339 of the Essai , after describing certain developments in galvanism , Aldini directs attention , as follows , to an experiment which he ascribes to the Genoese chemist Giuseppe Mojon :sx What then was the experiment carried out by Romagnosi ?sx