472 



the horizontal axis on which the magnet is suö|)ended. As bj eon- 

 tiriiioiis currents only the direction of the motion is given, so tiiat 

 it is possible to discriminate l>et\veen rising and falling, a two parted 

 collector C has been made nse of. with insnlated (i) brnshes B, 

 fixed on the frame R. 



Fig. 5 represents the scheme of the scansimeter. 



Besides the parts noted in lig. 4 by analogons symbols this fignre 

 shows the screw S, the ball-bearings K and the circular cover 0?////. 



sideways slightly con\ex. Gd is what is shown of the support in 

 which the common axis of the magnet and of. the frame R are 

 adjusted. 



The currents generated in the dynamo are measured with an 

 instrument, fixed in front of the pilot. It is preferable to choose an' 

 instrument of a special form, so that a rising of the hand corre- 

 sponds to a climbing of the machine and a lowering of the former 

 to a descent of the latter. Meters of the usual Desprez d'Arsonval 

 type are very practical for these determinations. 



To avoid the proportiojiality of the excursion to the speed of 

 rotation from being disturbed by reaction from the armature, it is advi- 

 sable to keep the current as weak as possible, consequently to give 

 the measurings the character more of determinations of potential 



