The "Drehstrom" Patent

Nikola Tesla was a Serbian-American inventor, electrical engineer, mechanical engineer, physicist, and futurist. He was widely known for his contribution to the creation of devices that operate on alternating current, multiphase systems and the motor will make a so-called second phase of the industrial revolution. Tesla has received universal recognition as the outstanding electrical engineer and inventor.
This article contains the letter of Nikola Tesla about the patent. The author narrated that there were two sets of field magnets, one at the neutral parts of the other. One of the sets, therefore, might as well be removed and placed a distance sideways, but long experience shows that in output, efficiency, cost of construction and in general mechanical respects such an arrangement is inferior. What happened with it? Read the book to know!