SHUDDEMAGEN. — DEMAGNETIZING FACTORS FOR IRON RODS. 215 



No figure was made for the curves, which are exhibited statistically 

 in Table IX, of December 1, 1906. 



The work up to this point indicates that the thicker rods have 

 smaller demagnetizing factors than the thin rods. To test this matter 



TABLE V. [Figure 10.] 

 October 20, 1906. 

 Diam. = 0.3969 cm. = 5/32 in. 

 Reversals. 



more carefully, a very long solenoid was built, probably the only one 

 of its size ever constructed. The wire was wound in a double coil 

 over a thick brass tube, making in all eight layers. The wire used 

 was the Annunciator No. 18, of diameter = 1 mm., with red insulation. 

 The dimensions of the solenoid are: 



