Historical Overview

In the late 1820s and early 1830s two of the worlds leading scientists, Michael Faraday and Joseph Henry were conducting a series of experiments utilising the newly discovered phenomenon of electromagnetism. This work led to a number of scientists endeavouring to develop practical electric motors.

The early electromagnetic engines can be broadly divided into two groups. The first to appear were the reciprocating engines. One problem that faced the experimenters was converting the linear motion of an electromagnet into a rotary motion. Contemporary steam engines solved this problem by the use of connecting rods and cranks, and initially it seemed logical to follow suit. These reciprocating electromagnetic engines are a fascinating example of one of technology’s dead ends.

Reciprocating Engine

A Reciprocating Engine of about 1850

The second group were the rotary engines pioneered by Paul-Gustav Froment. These did away with the connecting rods and linkages of the reciprocating engine and evolved into the modern electric motor.

Although the electric motor was an important development as a new power source, the alternatives at that time being water, wind, or steam, it would be many years before it became widely used. The problem was that the only practical source of electricity supply in the 1840s was batteries, reliable electrical power distribution did not become available until well into the second half of the nineteenth century. In the 1840s it was estimated that an electric motor powered by zinc/carbon batteries cost seventy times more to run than a coal fired steam engine of equivalent power.

Some Of The Pioneers

Michael Faraday (1791-1867)

If one accepts a broad definition of "motor", i.e. any apparatus that converts electrical energy into motion, the first electric motors were those developed by Michael Faraday in 1821. These were purely laboratory demonstrations and had no practical application. A metal wire was suspended in a cup of mercury, in which was placed a permanent magnet. When a current was applied to the wire it rotated around the magnet.

Peter Barlow (1776-1862)

A development of Faraday’s apparatus is Barlow's wheel (sometimes also known as a Faraday wheel) designed by the English mathematician and physicist Peter Barlow. A spiked wheel is mounted so that one spike just dips into a bath of mercury. When a current is applied the wheel rotates.

Barlow's Wheel

Barlow's Wheel

Joseph Henry (1797-1878)

In 1831 the American scientist Joseph Henry built a small experimental electromagnetic engine. Unfortunately no picture of this device has yet been found.

Charles Grafton Page (1812-1868)

One of the most prolific inventors in this field was Charles Grafton Page, of Salem, Massachusetts. At first Page, like many of his contemporaries, adapted the reciprocating technology found in steam engines and in 1838 designed an electromagnetic beam engine. This engine was probably the first practical electric motor to be built and was used to power a drill.

Electromagnetic Beam Engine

An Electromagnetic Beam Engine Designed By Charles Grafton Page

In a paper published in the American Journal of Science, vol. XXXV in 1839, Dr. Page wrote:

"As a proof that electromagnetism is susceptible of useful application where only a small power is wanted, a small engine was made by Mr. Davis in the month of July last, by the aid of which, an individual gains fifteen dollars per day by the simple operation of drilling the steel plates for gas burners. I think this may be considered the first instance in which the mechanical application of electromagnetism has been turned to profitable account."

He continued his work in this area and went on to develop a number of further reciprocating designs including a rather more elegant rocking armature engine.

Page went on to develop range of rotary engines, his Revolving Magnet engine was probably the first recognisable version of the modern DC motor/generator.

Luigi Magrini (1802-1868)

Luigi Magrini was born in Udine, Italy. He also designed a reciprocating electric engine which is on display in the Museum of The History of Science at Florence.

Paul-Gustav Froment (1815-1865)

A different approach was employed by the Frenchman Paul-Gustav Froment. In 1844 he developed a motor that utilised an electromagnet to attract iron bars mounted on a flywheel. This design did away with the need for mechanical linkages and, therefore, reduced the number of moving parts. Froment's engine was more efficient and was the next step that would eventually lead to the development of the modern electric motor.

Froment Motor

An Early Froment Motor

Sir Charles Wheatstone (1802-1875)

Sir Charles Wheatstone also produced electromagnetic engines. His engines, like Froment's, were a rotary design and had no mechanical linkages. Wheatstone realised that electromagnets produce a large force only at very short range. In an attempt to increase the effiency of his engines he used a characteristic "saw tooth" configuration for his rotors.

Wheatstone Engine

A Wheatstone Rotating Armature Motor

Wheatstone also pioneered another design. This had armature coils rotating within a fixed soft iron ring. Wheatstone’s rotating coil design led eventually to the modern DC motor, which has a fixed magnet in place of the iron ring.

Wheatstone Engine

A Wheatstone Rotating Coil Motor

Zénobe Gramme (1826-1901)

Zénobe Gramme, a Belgian electrical engineer, invented the Gramme Machine which was a DC (Direct Current) generator capable of producing much higher voltages than the dynamos known up to that point. It was the first generator to produce power on a commercial scale.

In 1873 he accidentally discovered that his machine was reversible and would spin when connected to a DC power supply. The Gramme Machine became the first "modern" DC electric motor and was successfully used in industry.