HYDRODYNAMICS AND ELECTRICITY. 253 



The question, " By what way and by whom was the peacock 

 brought into Italy ? " is shrouded in deep darkness ; and the supposi- 

 tion of Hehn, that it was brought thither directly from Phoenicia or 

 Carthage, stands upon doubtful testimony. It was, however, cordially 

 received and prized in that country, especially in the later times of 

 senseless luxury. The orator Hortensius, a contemporary of Cicero, 

 was the first to bring the peacock roasted upon the table, and, despite 

 the lack of palatableness in its flesh, his example seems to have been 

 extensively imitated. 



From Italy the peacock found its way into the rest of Europe, and 

 became in Christian lands the subject of a double symbol. On one 

 side it was regarded as an emblem of immortality, for the story gained 

 credence that its flesh was incorruptible ; on the other hand, it served 

 as an exhortation to humility, according to the well-known proverb, 

 " The peacock has a brilliant coat of feathers, but do not look down 

 at its feet." 



Reference was made, too, to its sneaking walk and its vicious char- 

 acter, especially in old age. But the knight gladly adorned his hel- 

 met with its feathers, and the custom at great banquets of bringing to 

 the table, amid the flourish of trumpets, a roasted peacock adorned 

 with its own feathers, and of taking a vow thereupon, lasted down to the 

 end of the middle ages. In more recent times, however, the bird, to- 

 gether with its flesh and its feathers, has fallen into discredit ; and it 

 is left to the Chinese mandarin to carry the peacock's feathers as a 

 sign of rank. 



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HYDRODYNAMICS AND ELECTRICITY. 



VISITORS at the recent Electrical Exposition in Paris were much 

 interested in an apparatus exhibited by Dr. C. A. Bjerknes, of 

 the University of Christiania, Norway, for the illustration of certain 

 properties in hydrodynamics analogous to some of the manifestations 

 of electricity and magnetism. Professor Bjerknes has been carrying 

 on his investigations in this line for nearly twenty years, having pub- 

 lished his first paper, " On the Internal Condition of an Incompress- 

 ible Fluid in which a Sphere of Variable Volume is moving," in 1863, 

 and having followed it up with numerous other j)apers relating to 

 similar problems. The results of experiments in every case corre- 

 sponded with those which had previously been indicated to him by 

 mathematical calculations. The experiments had in view the study of 

 molecular movements by reproducing mechanically, but in the inverse 

 sense, as the results proved, the simple and fundamental electrical and 

 magnetic phenomena. 



Pulsating and scillating bodies are applied so as to produce vibra- 



