26 HEYL & BRIGGS— THE EARTH INDUCTOR COMPASS. 



mobile, where instruments of this and similar types are frequently 

 installed. 



The earth inductor itself is shown in Fig. lo (photograph). It 

 is installed in the fuselage, behind the second seat. The supporting 

 board i runs athwart the ship and is clamped to the upper wooden 



Fig. 10 



members (longerons). Through the upper fabric of the fuselage 

 (the turtle back) projects the driving axle 2 bearing the four-cup 

 propeller j. This axle runs in ball bearings 4 of the self -aligning 

 type. The axle 2 is joined to the axle d by a short piece of flexible 

 shaft 10. 



A decided novelty is introduced in this invention in the use of an 

 iron core in the armature. For an iron-cored armature revolving in 



