Jonathan Nash Hearder
Encyclopedia
Jonathan Nash Hearder was a British
electrical engineer
, inventor, and educator. He is best known for his work in developing alternative experimental procedures for use by the blind and vision impaired, and for his early innovation in the field of induction coil
s.
, Devon
on December 24, 1809, the son of Jonathan Hearder (1775–1838, an umbrella maker and police constable)
and Mary Hannah Hearder (née Parry). He was the eldest of four children, with one brother (George Parry Hearder) and two sisters (Mary Hannah Treleaven and Anne Eliza Page).
Hearder became interested in science at an early age, despite his father being "greatly averse to such pursuits". From the age of 17 Hearder gave lectures on topics of science at the Exeter Literary Institution and other local societies. He began a career as a schoolmaster, and was the first schoolmaster in Plymouth to include science as a subject in the school curriculum.
In 1830, at the age of 23, Hearder's vision was severely damaged during an accidental explosion while experimenting with the explosive compound silver fulminate
. He was frequently described by many (including himself) as totally blind, although John Charles Bucknill in his book The Medical Knowledge of Shakespeare relates a demonstration given by Hearder in which Hearder claimed to be able to perceive a particularly bright flash of electrical light. It became Hearder's practice to wear green spectacles to conceal his damaged eyes.
Following the damage to his eyes, Hearder's school closed, and Hearder briefly turned to a secondary career in music. However, despite his vision impairment, Hearder continued lecturing and continued to work in experimental science, most particularly in the field of electrical engineering. He began work on developing alternative experimental procedures which did not rely on visual cues.
On October 27, 1837, Hearder married Susan Plimsaul. She died two years later in 1839. On January 21, 1840 he married his cousin Joanna Sleep Hearder (1809–1887), with whom he went on to have five children.
In 1838 Hearder's father died and Hearder assumed control of his father's umbrella-making business. He expanded the business to include the making of fishing tackle, an area in which he developed a strong reputation. According to the Royal Society of Chemistry he "could prescribe the particular fly to be used for successful troutfishing in any month, and for any stream in Devonshire." It was in this capacity that he was asked, late in life, to consult on the fishing gear that was to be used by the Challenger expedition
, and in fact the expedition eventually set sail bearing trammels and trawls furnished by Hearder for use in collecting shore fish for scientific purposes.
In 1845 Hearder was appointed consulting electrician and galvanist
to the South Devon and East Cornwall Hospital. In 1846, Hearder's mother passed away, aged 69, at the family house in Frankfort Street.
Hearder reportedly had an excellent memory, and held a passion for matters connected with local antiquity and history. He was an active member of the Devonshire Association
and the Royal Polytechnic Society. In 1871 Hearder reportedly received the degrees of PhD and DSc although it is not known which institution issued the qualifications.
On July 16, 1876, at the age of 67, Hearder died of a sudden paralytic seizure while at 13 Princess Square, Plymouth. He was buried at Ford Park, Plymouth.
. Although the invention of the induction coil is generally attributed to Heinrich Ruhmkorff, by some accounts Hearder may have independently invented the device at an earlier date. Hearder's son on one occasion vouched that he had personally conveyed his father to London to demonstrate a coil to Michael Faraday
a full two years prior to the announcement of Ruhmkorff's design.
In 1853 and 1854 Hearder exhibited "an induction coil, constructed by himself, with a condensor
which he also made himself, on principles which he had worked out [..] which gave with 4 cells of Groves’s battery
, better results than were obtained with the best instruments constructed by Ruhmkorff at that time."
In September 1856, Hearder was awarded the first Silver Medal of the Royal Cornwall Polytechnic Society
for his exhibition of "an arrangement of primary and secondary wires, with which sparks were obtained in air, and discharges several inches long, through
rarefied air
, and with which Leyden jar
s were charged." This induction coil
represented a substantial improvement over Heinrich Ruhmkorff's more famous 1851 design, using one-third the wire and generating a significantly greater effect.
Hearder was the inventor in 1842 of a magnetometer
, which he created with the object of ascertaining the rate of magnetic development in iron. This development also earned him a silver medal from the Polytechnic Society.
Hearder was an early advocate of the practicality of laying intercontinental submarine telegraph cables. He was asked to consult on the Atlantic Cable circa 1850, and proposed an improved design which used gutta percha as an insulator, a design which he later patented and a modified version of which was ultimately used in that project. He later consulted again during the laying of the cable, when it docked at Plymouth while evidencing apparent faults.
Hearder also invented several specialised forms of stove
.
’s spark gap, enabling him to feel perforation holes and thus estimate the coil's frequency, which also sounded as an audible tone. In 1858, when Hearder was asked to advise on the faulty Atlantic Cable prior to the departure of the cable ship Agamenmnon from Plymouth's Keyham Dockyard, Hearder reported testing the cable by inserting his tongue into the 2500-mile-long circuit to determine the electrical resistance of the wire.
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
electrical engineer
Electrical engineering
Electrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics and electromagnetism. The field first became an identifiable occupation in the late nineteenth century after commercialization of the electric telegraph and electrical...
, inventor, and educator. He is best known for his work in developing alternative experimental procedures for use by the blind and vision impaired, and for his early innovation in the field of induction coil
Induction coil
An induction coil or "spark coil" is a type of disruptive discharge coil. It is a type of electrical transformer used to produce high-voltage pulses from a low-voltage direct current supply...
s.
Biography
Hearder was born in PlymouthPlymouth
Plymouth is a city and unitary authority area on the coast of Devon, England, about south-west of London. It is built between the mouths of the rivers Plym to the east and Tamar to the west, where they join Plymouth Sound...
, Devon
Devon
Devon is a large county in southwestern England. The county is sometimes referred to as Devonshire, although the term is rarely used inside the county itself as the county has never been officially "shired", it often indicates a traditional or historical context.The county shares borders with...
on December 24, 1809, the son of Jonathan Hearder (1775–1838, an umbrella maker and police constable)
and Mary Hannah Hearder (née Parry). He was the eldest of four children, with one brother (George Parry Hearder) and two sisters (Mary Hannah Treleaven and Anne Eliza Page).
Hearder became interested in science at an early age, despite his father being "greatly averse to such pursuits". From the age of 17 Hearder gave lectures on topics of science at the Exeter Literary Institution and other local societies. He began a career as a schoolmaster, and was the first schoolmaster in Plymouth to include science as a subject in the school curriculum.
In 1830, at the age of 23, Hearder's vision was severely damaged during an accidental explosion while experimenting with the explosive compound silver fulminate
Silver fulminate
Silver fulminate is an explosive, ionic, fulminic acid salt of silver.Silver fulminate is a primary explosive that has very little practical value due to its extreme sensitivity to impact, heat, pressure and electricity...
. He was frequently described by many (including himself) as totally blind, although John Charles Bucknill in his book The Medical Knowledge of Shakespeare relates a demonstration given by Hearder in which Hearder claimed to be able to perceive a particularly bright flash of electrical light. It became Hearder's practice to wear green spectacles to conceal his damaged eyes.
Following the damage to his eyes, Hearder's school closed, and Hearder briefly turned to a secondary career in music. However, despite his vision impairment, Hearder continued lecturing and continued to work in experimental science, most particularly in the field of electrical engineering. He began work on developing alternative experimental procedures which did not rely on visual cues.
On October 27, 1837, Hearder married Susan Plimsaul. She died two years later in 1839. On January 21, 1840 he married his cousin Joanna Sleep Hearder (1809–1887), with whom he went on to have five children.
In 1838 Hearder's father died and Hearder assumed control of his father's umbrella-making business. He expanded the business to include the making of fishing tackle, an area in which he developed a strong reputation. According to the Royal Society of Chemistry he "could prescribe the particular fly to be used for successful troutfishing in any month, and for any stream in Devonshire." It was in this capacity that he was asked, late in life, to consult on the fishing gear that was to be used by the Challenger expedition
Challenger expedition
The Challenger expedition of 1872–76 was a scientific exercise that made many discoveries to lay the foundation of oceanography. The expedition was named after the mother vessel, HMS Challenger....
, and in fact the expedition eventually set sail bearing trammels and trawls furnished by Hearder for use in collecting shore fish for scientific purposes.
In 1845 Hearder was appointed consulting electrician and galvanist
Galvanism
In biology, galvanism is the contraction of a muscle that is stimulated by an electric current. In physics and chemistry, it is the induction of electrical current from a chemical reaction, typically between two chemicals with differing electronegativities....
to the South Devon and East Cornwall Hospital. In 1846, Hearder's mother passed away, aged 69, at the family house in Frankfort Street.
Hearder reportedly had an excellent memory, and held a passion for matters connected with local antiquity and history. He was an active member of the Devonshire Association
The Devonshire Association
The Devonshire Association is a learned society founded in 1862 by William Pengelly and modelled on the British Association, but concentrating on research subjects linked to Devon in the fields of science, literature and the arts.-History:...
and the Royal Polytechnic Society. In 1871 Hearder reportedly received the degrees of PhD and DSc although it is not known which institution issued the qualifications.
On July 16, 1876, at the age of 67, Hearder died of a sudden paralytic seizure while at 13 Princess Square, Plymouth. He was buried at Ford Park, Plymouth.
Inventions
Throughout his life, Hearder undertook significant work on the development of the induction coilInduction coil
An induction coil or "spark coil" is a type of disruptive discharge coil. It is a type of electrical transformer used to produce high-voltage pulses from a low-voltage direct current supply...
. Although the invention of the induction coil is generally attributed to Heinrich Ruhmkorff, by some accounts Hearder may have independently invented the device at an earlier date. Hearder's son on one occasion vouched that he had personally conveyed his father to London to demonstrate a coil to Michael Faraday
Michael Faraday
Michael Faraday, FRS was an English chemist and physicist who contributed to the fields of electromagnetism and electrochemistry....
a full two years prior to the announcement of Ruhmkorff's design.
In 1853 and 1854 Hearder exhibited "an induction coil, constructed by himself, with a condensor
Capacitor
A capacitor is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric ; for example, one common construction consists of metal foils separated...
which he also made himself, on principles which he had worked out [..] which gave with 4 cells of Groves’s battery
William Robert Grove
Sir William Robert Grove PC QC FRS was a judge and physical scientist. He anticipated the general theory of the conservation of energy, and was a pioneer of fuel cell technology.-Early life:...
, better results than were obtained with the best instruments constructed by Ruhmkorff at that time."
In September 1856, Hearder was awarded the first Silver Medal of the Royal Cornwall Polytechnic Society
Royal Cornwall Polytechnic Society
The Royal Cornwall Polytechnic Society is an educational, cultural and scientific charity, based in Falmouth, Cornwall, England, United Kingdom. The Society exists to promote innovation in the arts and sciences...
for his exhibition of "an arrangement of primary and secondary wires, with which sparks were obtained in air, and discharges several inches long, through
rarefied air
Rarefaction
Rarefaction is the reduction of a medium's density, or the opposite of compression.A natural example of this is as a phase in a sound wave or phonon. Half of a sound wave is made up of the compression of the medium, and the other half is the decompression or rarefaction of the medium.Another...
, and with which Leyden jar
Leyden jar
A Leyden jar, or Leiden jar, is a device that "stores" static electricity between two electrodes on the inside and outside of a jar. It was invented independently by German cleric Ewald Georg von Kleist on 11 October 1745 and by Dutch scientist Pieter van Musschenbroek of Leiden in 1745–1746. The...
s were charged." This induction coil
Induction coil
An induction coil or "spark coil" is a type of disruptive discharge coil. It is a type of electrical transformer used to produce high-voltage pulses from a low-voltage direct current supply...
represented a substantial improvement over Heinrich Ruhmkorff's more famous 1851 design, using one-third the wire and generating a significantly greater effect.
Hearder was the inventor in 1842 of a magnetometer
Magnetometer
A magnetometer is a measuring instrument used to measure the strength or direction of a magnetic field either produced in the laboratory or existing in nature...
, which he created with the object of ascertaining the rate of magnetic development in iron. This development also earned him a silver medal from the Polytechnic Society.
Hearder was an early advocate of the practicality of laying intercontinental submarine telegraph cables. He was asked to consult on the Atlantic Cable circa 1850, and proposed an improved design which used gutta percha as an insulator, a design which he later patented and a modified version of which was ultimately used in that project. He later consulted again during the laying of the cable, when it docked at Plymouth while evidencing apparent faults.
Hearder also invented several specialised forms of stove
Stove
A stove is an enclosed heated space. The term is commonly taken to mean an enclosed space in which fuel is burned to provide heating, either to heat the space in which the stove is situated or to heat the stove itself, and items placed on it...
.
Work on alternative experimental procedures
During his life Hearder developed many alternative experimental procedures which were usable by those with sight impairments. These procedures included steadily moving a paper strip through an induction coilInduction coil
An induction coil or "spark coil" is a type of disruptive discharge coil. It is a type of electrical transformer used to produce high-voltage pulses from a low-voltage direct current supply...
’s spark gap, enabling him to feel perforation holes and thus estimate the coil's frequency, which also sounded as an audible tone. In 1858, when Hearder was asked to advise on the faulty Atlantic Cable prior to the departure of the cable ship Agamenmnon from Plymouth's Keyham Dockyard, Hearder reported testing the cable by inserting his tongue into the 2500-mile-long circuit to determine the electrical resistance of the wire.
See also
- Elizabeth Cavicchi, "Blind Experimenting in a Sighted World: The Electrical Innovations of Jonathan Nash Hearder", Proceedings of the Plymouth Athenaeum, X, 2004/2007, 39-48.