340 J. Nicklés on Different Applications of Magnetic Attraction. 
ample, influencing the part of the wheel above the helix, the other, 
austral, the lower portion; and as the helix is placed as near as 
possible to the point of contact, this last portion must be more 
strongly magnetized than the upper, the austral being concentrated 
on the smaller space. 
The apparatus in figure 4 served to verify these different effects. 
The roller T is for receiving the cord which is wound’ upon the 
motor axle KE (fig. 3), and which corresponds to the moving 
power ; P represents the train to be transported. 
The weight P is increased until the car is ready to slide back ; 
as soon as the motion ceases, the current is let on, and immedi- 
ately the car starts off and draws the weight P; it descendsagain 
if the circuit is broken, and reascends on establishing it again, 
and so on. 
In this apparatus, each of the helices H and H’ consists of a 
brass box containing each 8 meters of copper wire of 0@-0071 in 
diameter, distributed in 77 turns, or 16 meters and 154 turns for 
both. The cord which sustains the weight P is fixed on N (fig. 3) 
the two modes of adhesion operating in this apparatus and between 
the pressures which produce the adhesion. 
Weight of car 5 kilogrammes. Grade 190 millimeters to the 
meter. One element of a battery of gas carbon. Total current 
tan 35° 10". Reduced current of the helices, tan 18° 257. 
Weight required for motion. Sum of Additional weight required to 
Ordinary adhesion. Magnetic adhesion. | adhesions.| replace the magnetic adhesion. 
5°500 kil 5100 kil. 16°600 3°500 
checks in use on railroads, they act upon the rails, and thus pre- 
serve the wheels which are rapidly worn by the ordinary checks ; 
