Editing Nicholas Callan

{{Short description|Irish physicist and Catholic priest (1799–1864)}}
{{EngvarB|date=October 2013}}
{{Use dmy dates|date=August 2023}}
{{Infobox scientist
| honorific_prefix  = [[The Reverend]]
| name              = Nicholas Callan
| image             = Nicholas Callan.jpg
| image_size        = 200px
| birth_name        = Nicholas Joseph Callan
| birth_date        = {{Birth date|1799|12|22|df=yes}}
| birth_place       = [[Dundalk]], [[County Louth]], <br/> [[Kingdom of Ireland]]
| death_date        = {{Death date and age|1864|01|10|1799|12|22|df=yes}}
| death_place       = [[Maynooth]], [[County Kildare]], Ireland
| alma_mater        = {{Plain list|
* [[St Patrick's Pontifical University, Maynooth|Maynooth College]]
* {{No wrap|[[Sapienza University of Rome|Sapienza University]] ([[Doctor of Divinity|DD]], 1826)}}
}}
| known_for         = Inventing the [[induction coil]] (1836)
| title             = Professor of [[Natural Philosophy]]
| term              = 1826–1864
| fields            = [[Physics]]
| work_institutions = Maynooth College 
| academic_advisors = [[Cornelius Denvir]]
{{Infobox clergy 
| child             = yes
| religion          = [[Christianity]]
| church            = [[Catholic Church]]
| ordained          = 1823
}}
}}

'''Nicholas Joseph Callan''' (22 December 1799 – 10 January 1864) was an Irish [[physicist]] and [[Priesthood in the Catholic Church|Catholic priest]] known for his work on the [[induction coil]].<ref name="boy">{{cite book|last=Boylan|first= Henry |year=1998|title=A Dictionary of Irish Biography, 3rd Edition|page= 55|location=Dublin|publisher= Gill and MacMillan|isbn = 0-7171-2945-4}}</ref>

==Early life and education==
He was born and raised in [[Dundalk]], [[County Louth]], where he attended school at an academy. His local parish priest, Father Andrew Levins, then took him in hand as an [[Altar server|altar boy]] and Mass server, and saw him start the priesthood at [[Navan]] seminary. He entered Maynooth College in 1816. In his third year at [[Maynooth]], Callan studied natural and experimental philosophy under [[Cornelius Denvir]]. He introduced the experimental method into his teaching and had an interest in electricity and [[magnetism]].<ref name="boy" />

Callan was ordained a priest in 1823 and went to Rome to study at [[Sapienza University of Rome|Sapienza University]], obtaining a [[doctor of divinity|doctorate in divinity]] in 1826. While in Rome he became acquainted with the work of the pioneers in electricity such as [[Luigi Galvani]] (1737–1798) who was a pioneer in [[bioelectricity]] and [[Alessandro Volta]] (1745–1827) who is known especially for the development of the [[electric battery]]. In 1826, Callan returned to Maynooth as the new professor of [[natural philosophy]] (now called [[physics]]), where he also began working with electricity in his basement laboratory at the college.<ref>[http://www.ucc.ie/academic/undersci/pages/sci_nicholascallan.htm] Reville, William. Nicholas Callan: Priest Scientist at Maynooth. The Irish Times, 21 February 2002.</ref>

==Induction coil==
{{main|Induction coil}}
[[File:Callan's Induction Coil (1845).jpg|alt=Callan's Induction Coil at the National Science Museum, Maynooth|thumb|Callan's Induction Coil at the National Science Museum, Maynooth]]
Influenced by [[William Sturgeon]] and [[Michael Faraday]], Callan began work on the idea of the [[induction coil]] in 1834. He invented the first induction coil in 1836.<ref>Callan, N.J. (December 1836) "On a new Galvanic battery," ''Philosophical Magazine'', series 3, vol. 9, pages 472–478; see especially [https://books.google.com/books?id=c5IOAAAAIAAJ&pg=PA477 page 477].</ref><ref>Callan, N.J. (April 1837) [https://books.google.com/books?id=SXgMAAAAYAAJ&pg=PA229 "A description of an electromagnetic repeater, or of a machine by which the connection between the voltaic battery and the helix of an electromagnet may be broken and renewed several thousand times in the space of one minute,"] Sturgeon's ''Annals of Electricity'', vol. 1, pages 229–230 and Fig. 52 on [https://books.google.com/books?id=SXgMAAAAYAAJ&pg=PA522 page 522].</ref><ref>Stanley A. Czarnik (March 1992) "The classic induction coil," ''Popular Electronics'', pages (?).  Available on-line at:  {{cite web |url=http://www.sentex.net/~mec1995/circ/hv/classic/classic.html |title=The Classic Induction Coil, Induction, Coils, HV |accessdate=2016-04-22 |url-status=dead |archiveurl=https://web.archive.org/web/20161030062249/http://www.sentex.net/~mec1995/circ/hv/classic/classic.html |archivedate=30 October 2016 }} .</ref> An induction coil produces an intermittent [[high-voltage]] [[alternating current]] from a low-voltage [[direct current]] supply. It has a primary coil consisting of a few turns of thick wire wound around an [[Magnetic core|iron core]] and subjected to a low voltage (usually from a [[Electric battery|battery]]). Wound on top of this is a secondary coil made up of many turns of thin wire. An iron armature and make-and-break mechanism repeatedly interrupts the current to the primary coil, producing a high-voltage, rapidly alternating current in the secondary circuit.

Callan invented the induction coil because he needed to generate a higher level of electricity than currently available. He took a bar of soft iron, about {{convert|2|ft|m}} long, and wrapped it around with two lengths of copper wire, each about {{convert|200|ft|m}} long. Callan connected the beginning of the first coil to the beginning of the second. Finally, he connected a battery, much smaller than the enormous contrivance just described, to the beginning and end of the winding one. He found that when the battery contact was broken, a shock could be felt between the first terminal of the first coil and the second terminal of the second coil.

Further experimentation showed how the coil device could bring the shock from a small battery up to the strength level of a big battery. So, Callan tried making a bigger coil. With a battery of only 14 seven-inch (178&nbsp;mm) plates, the device produced power enough for an electric shock "so strong that a person who took it felt the effects of it for several days". Callan thought of his creation as a kind of [[electromagnet]]; but what he actually made was a primitive induction transformer.

Callan's induction coil also used an [[interrupter]] that consisted of a rocking wire that repeatedly dipped into a small cup of [[mercury (element)|mercury]] (similar to the interrupters used by [[Charles Grafton Page|Charles Page]]). Because of the action of the interrupter, which could make and break the current going into the coil, he called his device the "repeater." Actually, this device was the world's first [[transformer]].<ref>{{cite web |last1=Guarnieri |first1=Massimo |title=Who Invented the Transformer? |url=https://www.researchgate.net/publication/260712565 |website=ResearchGate |accessdate=13 September 2019}}</ref> Callan had induced a high voltage in the second wire, starting with a low voltage in the adjacent first wire. And the faster he interrupted the current, the bigger the spark. In 1837 he produced his giant induction machine: using a mechanism from a clock to interrupt the current 20 times a second, it generated {{convert|15|in|mm|adj=on}} sparks, an estimated 60,000 volts and the largest artificial bolt of electricity then seen.

==The 'Maynooth Battery' and other inventions==
Callan experimented with designing batteries after he found the models available to him at the time to be insufficient for research in electromagnetism. ''The Year-book of Facts in Science and Art,'' published in 1849,<ref>The Year-book of Facts in Science and Art (p.156), 1849, John Timbs</ref> has an article titled "The Maynooth Battery" which begins "We noticed this new and cheap Voltaic Battery in the Year-book of Facts, 1848, p. 14,5. The inventor, the Rev. D. Callan, Professor of Natural Philosophy in Maynooth College, has communicated to the Philosophical Magazine, No. 219, some additional experiments, comparing the power of a cast-iron (or Maynooth) battery with that of a Grove's of equal size." Some previous batteries had used rare metals such as platinum or unresponsive materials like carbon and zinc. Callan found that he could use inexpensive cast-iron instead of platinum or carbon. For his Maynooth battery, he used iron casting for the outer casing and placed a zinc plate in a porous pot (a pot that had an inside and outside chamber for holding two different types of acid) in the centre. Using a single fluid cell he disposed of the porous pot and two different fluids. He was able to build a battery with just a single solution.

While experimenting with batteries, Callan also built the world's largest battery at that time. To construct this battery, he joined 577 individual batteries ([[electrochemical cell|"cells"]]), which used over 30 gallons of acid.<ref>Nicholas Callan (July 1848) [https://books.google.com/books?id=PFYwAAAAIAAJ&pg=PA49 "On the construction and power of a new form of Galvanic battery,"] ''Philosophical Magazine'', series 3, vol. 33, no. 219, pages 49–53.</ref> Since instruments for measuring current or voltages had not yet been invented, Callan measured the strength of a battery by measuring how much weight his electromagnet could lift when powered by the battery. Using his giant battery, Callan's electromagnet lifted 2 tons.<ref>M.T. Casey (December 1985) "Nicholas Callan – priest, professor and scientist," ''IEE Proceedings'', vol. 132, pt. A, no. 8, pages 491–497; see especially page 492.  Available on-line at:  http://eprints.nuim.ie/1767/1/CaseyCallan.pdf.</ref> The Maynooth battery went into commercial production in London. Callan also discovered an early form of [[galvanisation]] to protect iron from rusting when he was experimenting on battery design, and he patented the idea.<ref>Callan, Nicholas, "A means of protecting iron of every kind against the action of the weather and of various corroding substances so that iron thus protected will answer for roofing, cisterns, baths, gutters, pipes, window-frames, telegraph-wires for marine and various other purposes,"  British patent no. 2340 (filed:  12 October 1853; issued:  25 November 1853).  See:  ''The Mechanics' Magazine'', vol. 59, no. 1576, [https://books.google.com/books?id=f5kAAAAAMAAJ&pg=PA337 pages 337–338] (22 October 1853).</ref>

He died in 1864 and is buried in the cemetery in St. Patrick's College, Maynooth.

==Legacy==
The Callan Building on the north campus of [[NUI Maynooth]], a university which was part of [[St Patrick's College, Maynooth|St Patrick's College]] until 1997, was named in his honour. In addition, Callan Hall in the south campus, was used through the 1990s for first-year science lectures including experimental & mathematical physics, chemistry and biology. The Nicholas Callan Memorial Prize is an annual prize awarded to the best final-year student in Experimental Physics.

==Publications==
* ''Electricity and Galvanism'' (introductory textbook), 1832

==See also==
*[[List of Catholic clergy scientists]]

==References==
{{reflist}}

==Notes==
* O'Hara, James G.''Callan, Nicholas Joseph (1799–1864)'', Oxford Dictionary of National Biography, Oxford University Press, 2004
* [http://www.corrosion-doctors.org/Biographies/CallanBio.htm Biography at corrosion-doctors.org]

==External links==
*Nicholas Callan at the [https://web.archive.org/web/20160418103039/http://maynoothcollege.ie/national-museum-maynooth/ Science Museum, Maynooth]
* {{Librivox author |id=16003}} (his translations)

{{Authority control}}

{{DEFAULTSORT:Callan, Nicholas}}
[[Category:1799 births]]
[[Category:1864 deaths]]
[[Category:Irish inventors]]
[[Category:20th-century Irish physicists]]
[[Category:Academics of St Patrick's College, Maynooth]]
[[Category:Alumni of St Patrick's College, Maynooth]]
[[Category:19th-century Irish Roman Catholic priests]]
[[Category:Christian clergy from County Louth]]
[[Category:Catholic clergy scientists]]
[[Category:Burials at Maynooth College Cemetery]]
[[Category:People from Dundalk]]
[[Category:Sapienza University of Rome alumni]]
[[Category:Scientists from County Louth]]