The article provides a description and geometric definition of a new concept - the interpolar line of a permanent magnet. A method of observing the actual interpolar line of a permanent magnet by means of a magnetic film is presented - with an explanation of its principle. The results of a new physical experiment on the phenomenon of winding of a conductor with current on a permanent magnet within its interpolar line are presented, which confirm the existence of such a line in any permanent magnet having two magnetic poles. An example of the course of the experiment for a selected permanent magnet and a conductor with current is given. A description of the reaction of forces acting on a conductor with current lying near the interpolar line of the permanent magnet is presented, which explains the principle of this phenomenon. Four cases of forces acting on a conductor with current near the interpolar line of a permanent magnet are compiled, which are the basis for further work using the interpolar line. The possibilities of using the results of the conducted physical experiment to build a group of novel of technical devices is indicated.