Notice sur des Expériences exécutées avec la Machine Dynamo-électrique
et avec la Lampe á arc Voltaïque de M. Jürgensen

22 dynamo produced a light of about 4500 bees Carcel, a handregulating lamp being successively connected with each of the two dynamos by means of a cable 100 m. in length; the carbons used in the lamp were 20mm. in diameter, the positive carbon being surrounded with a thin sheet of copper; while the lamp was burning the distance between the carbons was 5 mm. The dimensions of the two dynamos were as follows: the french dynamo. the danish dynamo. Length of the machine m. 1,08 m. 1,02 Width „ — — 0,8 3 0,81 Height „ — — 0,93 0,6 5 Section of wire in the armature mm. 4,8 B g Length „ — „ — — m. 460 m. 500 Section of wire on the field magnet mm. 3,s mm. 6 Length „ — „ — — — m. 3160 m. 400 The resistance in the armature of the Jürgensen dynamo was one fourth of the total resistance — c. 0,3 Ohm, while the resistance in the armature of the Gramme machine was 0,i78 Ohm, the total resistance being 0,424 Ohm. At a later experiment the Jürgensen dynamo was kept rotating for 4 hours, during all which time it produced a quiet and steady light, the short period ex- cepted, necessary to replace the carbons with new ones, the first set being consumed. At the end of the ex- doubtedly would have been still more to the advantage of the danish dynamo.