Paul G-ebhardt, Berlin S. 



149 



Fig. 4. 



Electricity: 



Compound magnet (2 bar-magnets with arma- 

 ture). Magnet Needle on stand. 



Declination and inclination compass (Fig. 4), 



on brass stand with levelling screws, divided 



circle , micrometer adjustment and needle 

 with agate cap. 



Gold-leaf electroscope, with condenser discs. 

 Self-exciting Electrical Induction Machine with 



one fixed and one revolving disc; powerful. 



Fulminating tube, Fulminating plate, 

 Rotating globe on isolated stand, 

 Smoke condensing apparatus. 



Bertram's galvanometer with silvered 

 dial. (Fig. 5) 



Motor for rotating Geissler's tubes, with tube. 



Morse apparatus with clock-work and keys. 



Apparatus for rotating a movable magnet 

 round a stationary circuit, a magnet 

 round its own axis and a movable 

 circuit round a magnet. 



NEW! Apparatus for demonstrating the 

 galvanic current surrounding a fixed 

 magnet, with commutator. 



Du Bois-Reymond's induction apparatus. 



Simple induction coil. 



Rumkorff Induction-coil, with condenser and commutator; also 



Geissler tube and holder. 



Geissler tube with uranium-glass figure, on stand. 

 Automatic carbon-regulator with reflector for electrical light. 



Miscellanea: 



Gravert's combined Wool-gauge and dynamometer, Menzel's Wool- 

 gauge. Hartmann's Wool-gauge, Thaer-Kleinert's Wool-gauge. 



Illustrated descriptive catalogues may be had gratis and post-free. 

 Physical and Chemical Laboratories supplied ivith complete outfit,' and special 

 estimate worked out. 



