XViii INTRODUCTION. 



Electrical Equivalent of Heat. Methods of determining. 

 Analysis of Solar Radiation. 



Magnetism. 



H Instruments and apparatus employed in teaching, and in the 

 investigations and observations connected with : 



Natural Magnets. 



Permanent Artificial Magnets. 



Electro- Magnets. 



Methods of Magnetization. Effects of Magnetization. Con- 

 ditions affecting intensity of Magnetization : Temperature (che- 

 mical), Composition, Strains, &c. 



Magnetic Induction of all Substances. Diamagnetism. 



Measurement of Intensity of Magnetization, Magnetic moment. 



Terrestrial Magnetism. Instruments for observation and auto^ 

 matic registration of the magnetic elements. 



Electricity. 



Instruments and apparatus employed in teaching, and in the 

 investigations and observations connected with : 



Production and Maintenance of Difference of Potential. 

 Electrical machines acting by friction, induction (doublers, re- 

 plenishers, &c., Holz's and Toppler's machines, &c.) ; Galvanic 

 batteries ; Thermo-electric piles ; Magneto-electric machines. 

 Other sources, such as Pyro-electricity, Pressure electricity, Cleav- 

 age, Capillarity, Osmose, &c. 



Detection and Measurement of Difference of Potential. Elec- 

 troscopes, Electrometers, Standards of electro-motive force, Me- 

 thods of comparison. 



Accumulation of Electricity. Insulators, Condensers, Accumu- 

 lators, Effects due to accumulated electricity, Distribution on con- 

 ductors, Polarization of dielectrics, &c. 



Measurement of Electric Quantity. Torsion balances, Stand- 

 ard accumulators, Methods of comparing electric capacities and 

 dielectric coefficients. 



Detection and Measurement of Electric Currents. Galvano- 

 scopes, Galvanometers, Voltameters, Electro- dynamometers, &c. 



Resistance. Standards of resistance, Methods of comparing 

 resistances, Methods of establishing absolute standards (British 

 Association unit appar.). 



Effects of Electric Currents. Production of light, heat, 

 Electrolysis, Electro-diffusion. Action on magnets, soft iron 

 (electro-magnets), Action of currents on currents. 



Technical Application of Electricity. Electric telegraph, &c. 



