No. 61 346. 



Moving-Magnet Mirror Galvanometers. 



883 



50 119, 61 345, 61 389. 1 : 9. 



61,336. Astatic 4-Coil Mirror Galvanometer after Du Bois and Eubens, Figure, with i s. d. 

 4 coils each of 20 ohms; one massive magnet system with rotary mirror, about 1 gramme 

 in weight, 1 medium-heavy magnet system 0.25 g weight (Electrot. Ztschr., 1894, p. 321; 

 cf. Gan.-Man., Fig. 761; Gan.-Bein., Fig. 832) 22.10.0 



The following should be ordered separate for above: 



61.337. Protecting Case ................ ' 



61.338. 1 Light Magnet System, approx. weight 0,1 g 



61.339. 4 Coils of each 2000 ohms 



61.340. 4 Metres Quartz Fibres in wood case 



61.341. 1 Shunt Resistance, l / 9 , l /,, g , V 



the galvanometer resistance 



The preceding instrument is of extraordinarily high sensitivity. 



61.342. Mirror Galvanometer after Thomson-Szymanski, Figure, with astatic magnet- 

 system and directing magnet, with wire connecting blocks for putting the coils in parallel, 

 in two groups and in series (cf. also Gan.-Man., Fig. 761; Gan.-Eein., Fig. 832) . . 



The four coils have a resistance of 4 ohms each. By removing the front wall the galvanometer 

 can be opened and therefore easily and quickly adjusted. The instrument is highly sensitive and is 

 very suitable for experiments with thermo-electric currents, for telephone currents, and for demon- 



strating i hi' ruiTcnts on cutting the lines of force. The case is of mahogany. 



61.343. Wall Bracket for above with lens and Glow Lamp for 110 220 volts, Figure, 

 for enabling the instrument to be used as a reflecting galvanometer ........ 



The voltage should be quoted in ordering; if not stated we supply a 110 volt lamp. 



61,344. Extra Price for a Nernst Lamp, which gives a bright luminous pointer. 

 110220 volts only 



For D. C. 



61,345. Fixing Device for suspended board No. 50,119, Figure, also rotary arm with lens 

 and scale-lamp. Price without suspended board 



By means of this device the galvanometer is firmly fixed on the suspended board, but in such 

 manner that it can be easily set up by adjusting the three levelling screws. 



The illustration shows a suspended board No. 50,119 with a Deprez-d'Aisonval Galvanometer 

 No. 61,389 with mirror reading used as a Reflecting Galvanometer; illumination by a single filament 

 electric lamp and with the above fixing device and rotary arm for the lamp. The device can, how- 

 ever, also be used with Galvanometer No. 61,342 and similar ones. As regards voltage etc. the same 

 remark applies as in No. 61,343. 



<>!..!!(>. Multiple Commutator for placing alongside the Lecture Table, for enabling the coils 

 of Galvanometer No. 61,342 to be put in parallel, series, and in two groups, F i g u r e, 

 without conned ing leads 



1. (I. O 



1. 10. 



5. 0. 



0. 8. 



5. 0. 



6. 0.0 



2. 5.0 



0. 8.0 



2. 0.0 



3. 0.0 



56* 



