312 SEC. 10. ELECTRICITY. 



1308. Induction Apparatus for medical use. 



Reiser and Schmidt, Berlin. 



1309. Spark Induction Machine, No. 1, with armature and 

 Geissler's tubes. Kciser and Schmidt, Berlin. 



1310. Spark Induction Machine, No. 2, with armature and 

 Geissler's tubes. Reiser and Schmidt, Berlin. 



1311. Spark Induction Machine, length of spark, six milli- 

 meters. Reiser and Schmidt, Berlin. 



1312. Spark Induction Apparatus, length of spark, one 

 centimeter. Reiser and Schmidt, Berlin. 



1313. Spark Induction Apparatus, length of spark, 4'o 

 centimeters. Reiser and Schmidt, Berlin. 



1314. Spark Induction Apparatus, length of spark, 8 

 centimeters. Reiser and Schmidt, Berlin. 



1315a. Great Induction Coil. 



66 Leyden jars and fittings. 

 6 stands for jars. 



The Roijal Polytechnic Institution. 



c. MAGNETO-ELECTRIC MACHINES. 



1303 a. First Induction Machine, called " de Pixii," 

 constructed under the direction of Ampere. 



College of France, Paris. 



1686. Galvanometer of Nobili. 



The Royal Institute of" Studii Superiori" at Florence. 



Rose of Metallic Colours obtained by means of electricity 

 by Leopoldo Nobili. 



The Royal Institute of " Studii Superiori" at Florence. 



A very great number of liquids and metals were subjected by Nobili to 

 experiments in order to obtain, by means of electricity, the coloured rings 

 which bear his name; and exceedingly important are his observations on 

 the complete scale of colours which he succeeded in forming and which yet 

 exist at Florence. 



1687. Original Magneto-electrical Machine of Leopoldo 

 Nobili and Vincenzo Antinori, which gave, on the 30th of 

 January 1832, the first spark, before Leopold II. 



The Royal Institute of " Studii Superiori " at Florence. 



This is the first machine with which the induction spark was obtained by 



means of an artificial magnet. The anchor (ancora) tied by a thread, and 



movable like a lever round a pivot, is detached from the loadstone by a blow, 



while at the same time, by means of a spring, the electrical circuit is in- 



