176 MEMOIE OF OERSTED. 



opposite directions." Tlie sequel of Ampere's labors showed " that the recipro- 

 cal action of tLe elements of two currents is exerted in conformity witli the line 

 which unites their centers ; that it depends on the mutual inclination of those 

 elements, and that it varies in intensity in the inverse ratio of the square of the 

 distances." Ampere finally succeeded in establishing that a conjunctive wire 

 W'ound into a helix with very close spires, is sensitive to the magnetic action of 

 the earth. For many weeks there was to be seen in his cabinet " a conjunctive 

 wire of platina whose position was determined by the action of the terrestrial 

 e-lobe." Ampere, by constructing a galvanic compass, had shown that the forces 

 which act in the magnetic needle are electric currents, and by his learned calcu- 

 lations on the reciprocal action of those currents he accounted for all the actions 

 which the conjunctive wire of the pile exerts, in the experiments of Oersted, on 

 the magnetic needle. 



Electro-magnetism had thus become the common glory of Oersted and Ampere, 

 and renown, by uniting the names of these two illustrious savants, not unnat- 

 urally calls attention to the resemblances or the contrasts which existed between 

 them. 



They were throughout nearly cotemporary. Ampere having been born the 22d 

 January, 1775, andOersted the 14th August, 1777. Both had entered upon life 

 in a very modest condition as regards fortune ; both had had slender means of 

 instruction, and had at first informed themselves with little help from masters 

 and even little from books. Oersted had composed poetry not destiixite of 

 merit ; Ampere, in his youth, wrote French verses replete with delicacy and 

 grace, some of which have appeared to M. Arago no unworthy ornaments for 

 his eulogy. Oersted always saw in the harmonics of nature a poetry superior 

 to all o'ther poetry ; Ampere, in the evening of his life, composed in Latin 

 verse a general tablet of the classification of the sciences, in which elegance 

 disputes the palm witli precision. 



Oersted, a declared disciple of Kant, applied his ideas to the material world 

 as a consummate physicist ; Ampere, an enthusiastic sympathizer with Maine de 

 Biran, Royer Collard, and Cousin, exercised his acute and powerful faculties 

 and manifested a lively interest in disentangling the most subtle problems of 

 metaphysics. Both were skilled in comnmnicating to their learned instructions 

 a peculiar attraction, though each in a different kind. Each of them has left, 

 among friends, colleagues, pupils, remembrances full of that affectionate admi- 

 ration which can never be effliced. 



Oersted made his first scientific essays in the pharmacy of his father ; before 

 all else he Avas a chemist. Ampere, at the age of thirteen, borrowed from the 

 public library of Lyons the mathematical works of Bernouilli ; he was born a 

 geometer, but the Encyclopedia having been his first book, he had, from his 

 infancy, embraced all the branches of human knowledge and had even become 

 profound in many of them. M. xirago has felt authorized to say of him, in 

 speaking of his labors in chemical classification, " that, during one of the last 

 revolutions of science, Ampere, the geometer Ampere, pi'oved always in the 

 right, even when his opinions were opposed to those of almost all the chemists 

 of the world." 



Without Oersted, electro-magnetism might not have existed ; without Ampere, 

 it miglit have been confined to an exceedingly curious, but limited experiment. 

 The co-operation of Oersted and Ampere made it, in a very little time, a com- 

 plete science, a science destined to change the face of the world by the sur- 

 prising applications of it wliich have been already realized, and in which it is 

 employed entire without distinction as to the origin of its different parts. 



I have often heard it asked who was the true inventor of the electric tele- 

 graph. Reference has been made to ingenious physicists, who in the course of 

 the last century transmitted to a distance, by means of the electric spark, 

 instantaneous signals. As well might the learned, when the brothers Chappe 



