302 SEC. 10. ELECTKICITY, 



1249c. Induction Electric Machine. J. Teller, Munchen . 



The fixed disc has neither holes nor cuts, which were hitherto considered 

 indispensable. 



1249d. Toepler's Induction Machine. 



Royal Institution of Great Britain. 



The apertures usual in the fixed disc are here dispensed with ae unnecessary, 

 the disc is thus rendered less breakable, and a greater action is obtained. 

 The apparatus is very simple in construction and can easily be taken asunder 

 for cleaning. The driving disc is at the same time utilised as the exciter of 

 -electricity. 



1250. Holtz's Electric Machine, with fixed induction 

 surface. Borchardt, Hanover. 



1251. Holtz's Electric Machine, with movable induction 

 surfaces. Borchardt, Hanover. 



1542d. Electric Machine, with large ebonite disc. 



C. Etler. 



1252. Machine for exciting Positive and Negative Elec- 

 tricity. E. Stohrer, Leipzig. 



It has the form of a small disc electric machine. According as one or 

 other brass ball at the end of the caoutchouc frame is taken hold of, a quantity 

 of positive or negative electricity is obtained. 



b. GALVANIC BATTERIES. 



1285a. Apparatus for Volta's Fundamental Experi- 

 ment, with arrangement for chloride of calcium, two brass, one 

 copper, one zinc plate, and insulating handle. 



Warmbrunn, Quilitz, <$* Co., Berlin. 



1253. Water Battery. 



The Council of King 's College, London. 



1254. Daniell's Battery, employed in researches by Pro- 

 fessor Daniell. The Council of King's College, London. 



1255. Early Voltaic Batteries: 



Babington's battery. 

 Cruikshank's 

 Wollaston's 

 Sturgeon's 



The Council of King 1 s College, London. 



1256. Hare's Calorimotor, or Deflagrator. 



The Council of King's College, London. 



1257. De La Hue's Powder Chloride of Silver Battery. 



Tisley and Spiller. 



