The solenoid engine or electromagnetic engine also known as a pulse motor was the forerunner to the modern electric motor. the following is taken from The Old Model Company
who sum it up much better than I can
When Michael Faraday in Great Britain and Joseph Henry in the United States both discovered electricity at roughly the same time no one knew what to do with it because in those days nothing worked on electricity.
In the thirty or so years that followed, between 1831 and 1861, the great experimenters of the day tried to use this new discovery by copying steam engine design and practice.
Many early electromagnetic engines were of reciprocating design and used connecting rods, beams and flywheels that had to be constantly accelerated.
These early reciprocating engines were quickly followed by revolving armature designs of which Paul Gustave Froment’s was the first in 1844. These were much more efficient and a variety of different and increasingly sophisticated designs emerged.
To fully understand the unique properties of the solenoid engine you need to track down a copy of Secrets of the Electric Motor
(it out there on the interwebs if you know which stone to look under)
This video is a scientific lecture is not for the faint of heart as it kicks some major science re many of the properties of the modern electric motor that we just take for granted because we know the motor works rather than learning why and how it works.
I lost my only copy of this video so I'm a very rusty on the topic, but if you can find this video you will learn allot maybe even more that 1 brain can handle. the video explores work by Tesla plus the other great minds of that golden age and more recently John Bedini who's motor has achieved over unity (if you mind is open enough to believe such things)
I intend to explore the world of the Bedini motor as part of a future project once i get my lathe operational and my engineering tolerances back down to those i was once capable of back in the day.