fschieber/wit-captions huggingface dataset:
Zdjęcie wykonane podczas sekcji zwłok ukazujące objawy zapalenia opon mózgowo-rdzeniowych wywołanego przez Streptococcus pneumoniae. Pinceta odciąga oponę twardą (biała) pod którą leżą opona pajęcza i opona miękka. Widoczny obrzęk i liczne wybroczyny (czerwone) oraz ropa (zielonkawe).
English: Autopsy: Brain surrounded by pus (the yellow-greyish coat around the brain, under the dura lifted by the forceps), the result of bacterial meningitis. A brain autopsy demonstrating signs of pneumococcal meningitis in an alcoholic patient. The forceps (center) are retracting the dura mater (white). Underneath the dura mater are the leptomeninges, which appear to be edematous and have multiple small hemorrhagic foci (red). Deutsch: Eitrige Haubenmeningitis durch Streptococcus pneumoniae.Autopsie-Befund: unter der zurückgezogenen Dura mater ist die putride Entzündungsreaktion mit kleinen Einblutungen zu erkennen. Русский: Вскрытие: мозг в окружении гноя (желто-сероватый слой вокруг мозга, оболочка поднимается щипцами), в результате бактериального менингита. Вскрытие мозга демонстрируют признаки менингита. Щипцы (в центре) оттягивают твердую мозговую оболочку (белый). Под твердой мозговой оболочки видны мягкая и паутинная оболочки мозга, которые отёчны и имеют несколько небольших очагов геморрагического воспаления(красный). Polski: Pneumokokowe zapalenie opon mózgowych. Zdjęcie wykonane podczas sekcji zwłok ukazujące objawy zapalenia opon mózgowo-rdzeniowych wywołanego przez Streptococcus pneumoniae. Pinceta odciąga oponę twardą (biała) pod którą leżą opona pajęcza i opona miękka. Widoczny obrzęk i liczne wybroczyny (czerwone) oraz ropa (zielonkawe). Pneumokokowe zapalenie opon mózgowo-rdzeniowych, treść ropna w przestrzeni podpajeczynówkowej. Italiano: Autopsia del cervello che mostra un'infezione da meningite pneumococcica in un paziente alcolizzato. Immagine autoptica di encefalo con evidenti depositi di pus dovuto alla presenza di Pneumococco della meningite. La pinza scosta la Dura madre per consentire di visualizzare l'infezione sottostante. Español: Las zonas de las orillas es el lugar donde ocurre más frecuentemente el sangrado. Ελληνικά: Αυτοψία: Εγκέφαλος ενδείξεις βακτηριακής μηνιγγίτιδας.
Rame des Chemins de fer économiques du Nord (CEN), une compagnie de chemin de fer secondaire, qui exploita une ligne à voie métrique de Lens à Frévent de 1895 à 1948[13]. Elle circule sur le boulevard des Écoles, où se tenait, en ce jour d'avant la Première Guerre mondiale, un marché.
Français : Carte postale ancienne éditée par la Librairie Delattre à Lens, n°3 :LENS - Boulevard des écoles
Vue depuis l'est de l'axe avec le Capitole, le National Mall, le Washington Monument et le Lincoln Memorial. Au centre, à droite, partant en biais, la Pennsylvania Avenue, reliant le Capitole à la Maison-Blanche. Au premier plan à gauche, le bâtiment de la Cour suprême des États-Unis.
English: Aerial view of Capitol Hill and the National Mall, Washington D.C..Français : vue aérienne de Capitol Hill avec le capitole des États-Unis. Au premier plan à gauche le bâtiment de la Cour suprême, en arrière-plan l'obélisque du Washington Monument.
The Monument National Canadien Français, former banquet and memorial hall of the first council of the Saint-Jean-Baptiste Society of America, six months before it was destroyed by fire in 1984. Built 1904, after 1938 it was identified largely as Kelley's Lobster House and Banquet Hall
English: The former Monument National Canadien Français in Holyoke, Massachusetts after its ground floor had been converted to a restaurant named Kelly's. In December of 1984, 6 months after this photo the building would be destroyed entirely in a fire attributed to arson. In its history the building's grand hall would host drama societies, city government banquets, religious services for a fledgling Holy Trinity Greek Orthodox Church, and a number of other functions both in the French and greater Holyoke communities.
Det gamle gravkapellet på gravlunden er no Vår Frelsers ortodokse kirke, kyrkjelydkyrkja for Hellige Olga menighet, som er Den russisk-ortodokse kyrkja (Moskvapatriarkatet) sin fyrste kyrkjelyd i Noreg i moderne tid, skipa i 1996. Kyrkja har tilkomst frå Akersveien. Foto: Chris Nyborg
Our Saviour's Orthodox Church, formerly the chapel on Vår Frelsers gravlund. Akersveien 33.
Prozent Ja-Stimmen nach Grafschaften (Counties)
 ﻿27,5–30,0 %
 ﻿30,0–32,5 %
 ﻿32,5–35,0 %
 ﻿35,0–37,5 %
 ﻿32,5–35,0 %
 ﻿42,5–45,0 %
 ﻿45,0–47,5 %
 ﻿47,5–50,0 %
 ﻿50,0–52,5 %
 ﻿52,5–55,0 %
 ﻿57,5–60,0 %
 ﻿60,0–62,5 %
 ﻿62,5–65,0 %
 ﻿65,0–67,5 %
 ﻿67,5–70,0 %
 ﻿72,5–75,0 %
 ﻿72,5–77,5 %
Una valla publicitaria que fomenta el secreto entre los trabajadores de Oak Ridge.
El Tío Sam se ha quitado el sombrero y se está arremangando. En la pared frente a él hay tres monos y el lema: Lo que ves aquí
Lo que haces aquí
Lo que oyes aquí
Cuando te vas de aquí
Que se quede aquí.
English: A billboard encouraging secrecy amongst Oak Ridge workers
The Neu England Rundschau or "New England Review", originally called the Holyoke Journal, it was the first and longest running German-language weekly published in Holyoke from 1884 to sometime around 1942; its parent business, the Hitchcock Press, remains extant in the city as of 2019
English: The masthead of the Neu England Runschau or "The New England Review", a German-language newspaper published in Holyoke, Massachusetts in the late 19th and early 20th centuries. The full issue may be seen on the Internet Archives, here.
Tom Erik Oxholm ble juniornorgesmester i allround. Han satte norsk junior-rekord sammenlagt liten firkamp og på 5 000 meter i tillegg til mesterskapsrekorder på på de samme to øvelsene i tillegg til 3 000 meter. Bildet er i fra skøytelandskampen i desember 1981 i Groningen, Nederland.
Nederlands: Schaatsinterland Nederland tegen Noorwegen in Groningen. Tom Erik Oxholm (Noorwegen) in actie.
Graph of the inversion technique from 
  
    
      
        x
      
    
    {\displaystyle x}
  
 to 
  
    
      
        F
        (
        x
        )
      
    
    {\displaystyle F(x)}
  
. On the bottom right we see the regular function and in the top left its inversion.
English: Graph of the inversion technique from x to F(x)
Reliquiario ex linteis Beatae Eugenii Bossilkov - Epyscopus et Martyr (1900-1952). Altro raro caso in cui sono disponiibili solo reliquie di II classe, essendo il Santo Corpo - Martire bulgaro dell'odio settario stalinista - introvabile (prov. Postulazione Cause dei Santi Passionista)
Italiano: Reliquiario ex linteis Beatae Eugenii Bossilkov - Epyscopus et Martyr (1900-1952). Altro raro caso in cui sono disponiibili solo reliquie di II classe, essendo il Santo Corpo - Martire dell'odio settario stalinista - introvabile
A Tádzs Mahal alaprajza: 1. Déli-kapu (Szírhi darváza); 2. melléksíremlékek, kertek; 3. előudvar (dzsilaukhána); 4–5. khavasszpurák (lakóépületek); 6. főkapu (Darváza-i Rauza); 7. csár bág; 8. vízi pavilonok; 9. mecset; 10. vendégház; 11. mauzóleum; 12. Jamuna folyó; 13. Holdfény-kert
Arbeits- und Regelbereich einer Heißwasseranlage: Der Druck-min-Begrenzer ist auf einen Druck eingestellt, der oberhalb des Sattdampfdruckes der abgesicherten Vorlauftemperatur liegt. Der Einstelldruck des Druck-max-Begrenzers liegt unterhalb des Ansprechdrucks des Sicherheitsventils.
Deutsch: Arbeits- und Regelbereich einer Heißwasserkesselanlage mit Druck- und Temperaturabsicherung
Villa Falconieri a Frascati, sede del Centro Europeo per l'Educazione, dal 1999 denominato INVALSI. A Villa Falconieri nel 1963 i delegati dei paesi dell'OCSE redassero il cosiddetto "Manuale di Frascati", riferimento internazionale per l'armonizzazione dei rilevamenti statistici.[30]
English: Frascati, Villa Falconieri.
Standbeeld van Alan Turing door Stephen Kettle van 1,5 ton, gemaakt van een half miljoen stukjes leisteen uit Wales, in opdracht van de Amerikaanse miljardair Sidney Frank. Aan de muur de portretfoto van Turing ten tijde van zijn verkiezing tot Fellow van de Britse Royal Society, 1951
English: The 1.5 -ton statue of Alan Turing, by Stephen Kettle commissioned by the American billionaire Sidney Frank. This statue at Bletchley Park is made of about half a million pieces of slate quarried in Wales. People who knew him say this takes their breath away. Unfortunately, you can't see his coffee cup under his desk. Nederlands: Het 1,5 ton wegend standbeeld van Alan Turing, gemaakt door Stephen Kettle in opdracht van de Amerikaanse miljardair Sidney Frank. Het standbeeld is opgetrokken uit ongeveer een half miljoen stukjes leistein uit Wales.
Schema di una lavorazione con fascio laser a stato solido. 1. Pezzo 2. Materiale vaporizzato e fuso espulso 3. Fascio laser 4. Lente 5. Semispecchio 6. Mezzo ottico attivo (rubino) 7. Involucro riflettente 8. Lampada flash 9. Specchio 10. Elettrodo di innesco 11. Interruttore circuito
Italiano: 1. Pezzo 2. Materiale vaporizzato e fuso espulso 3. Fascio laser 4. Lente 5. Semispecchio 6. Mezzo ottico attivo (rubino) 7. Involucro riflettente 8. Lampada flash 9. Specchio 10. Elettrodo di innesco 11. Interruttore circuito
Various spellings of the name "Hera" in ancient Greek. Left: original spelling, right: modern transcription. Red: consonantal "Heta", blue: vocalic "Eta".
 1.) archaic non-Ionic
 2.) classical Ionic
 3.) intermediate (e.g. Delphi)
 4.) intermediate (e.g. Tarentum)
 5.) late antiquity.
ACT-I-VATE panel at the 2009 Brooklyn Book Festival. Seated left to right on chairs are Joe Infurnari, Simon Fraser, Tom Hart, Dean Haspiel, Nathan Schreiber, Molly Crabapple, Tim Hamilton, and Jeff Newelt, acting as moderator. On the edge of the stage are Leland Purvis and Rami Efal.
English: Comics creators and ACT-I-VATE members (Seated left to right on chairs) Joe Infurnari, Simon Fraser, Tom Hart, Dean Haspiel, Nathan Schreiber, Molly Crabapple, Tim Hamilton, and moderator Jeff Newelt, and (seated on the edge of the stage) Jason Little, and Rami Efal, speaking on a panel about their work at the 2009 Brooklyn Book Festival.
Jacques, marquis de Maleville (1741-1824), président du tribunal de cassation, Auguste Gaspard, baron Boucher-Desnoyers (1779-1857), huile sur toile (1re moitié XIXe siècle), Musée de l'Histoire de France (Versailles).
On peut voir derrière le magistrat un volume du « Code Napoléon ».
A kalo lo'i harvest in Maunawili Valley. A lo'i is an irrigated, wetland terrace, or paddy, used to grow kalo (taro) or rice.[3] Ancient Hawaiians developed a sophisticated farming system for kalo, along with over 300 variations of the plant adapted to different growing conditions.[3]
Darstellung eines Königs, vermutlich Ludwigs des Deutschen, im sogenannten Ludwigspsalter aus dem späten 9. Jahrhundert. Ohne Zeichen seiner herrscherlichen Würde kniet der König am Kreuz Christi. (Berlin, Staatsbibliothek Preußischer Kulturbesitz, Ms. theol. lat. fol. 58, fol. 120r).
Miguel Hidalgo · Agustin de Iturbide · Juan Rulfo · Emiliano Zapata · Octavio Paz · Benito Juárez · Rodolfo Neri Vela · Juana Ines de la Cruz · Porfirio Díaz · Pancho Villa · Ximena Navarrete · Guillermo González Camarena · Carlos Fuentes · Carlos Slim Helú · Salma Hayek · Luis Miguel
A set of flashcards demonstrating the Leitner system. Cards that the learner knows are promoted to a box for less frequent review (indicated by green arrows); cards for which the learner has forgotten the meaning are demoted to be studied more frequently (indicated by rainbow arrows).
Quân chủ các nước theo chế độ kế vị.   Chế độ kế thừa con trưởng (không phân biệt nam nữ)   Tuyển chọn và Chế độ kế thừa con trưởng (chỉ chọn nam giới)   Chế độ kế thừa con trưởng (chỉ chọn nam giới)   Tuyển chọn   Chế độ kế thừa con trưởng (ưu tiên nam giới)   Chế độ kế thừa huynh đệ
English: World monarchies by succession.
Ganz links im Bild im steinernen Flussbett sind die Sprengversuche zur Vertiefung des Flussbettes des 18. Jahrhunderts anhand des Streifens tieferen Wassers zu erkennen: rechts im Bild der als Alternative erbaute Ems-Seitenkanal, der die Schiffbarkeit zumindest bis Greven ermöglichte.
English: Ems in Rheine (Germany) Deutsch: Ems in Rheine
Livonijas ordeņa Vīlandes cietokšņa rekonstrukcija. Augšpils: 1. kapella, 2. pārvaldes ēka, 3. tornis "Garais Hermanis", 4. klozete, 5. komtura rezidence, 6. graudu glabātava, 7. priesteru mītne, stallis. Priekšpils: 8. ēdamzāle, 9. noliktava, 10. zirgu stallis, 11. kalpotāju istabas.
Мапа македонског језика у свету
  Службени језик (Македонија и Албанија)
  Више од 80.000 говорника (Аустралија)
  Више од 60.000 говорника (Немачка)
  Више од 40.000 говорника (Грчка, САД, Италија)
  Више од 20.000 говорника (Србија, Канада)
  Мање од 20.000 говорника (остале државе)
English: Map showing the presence of Macedonian speakers in the countries of the world by shades of blue, based on Image:BlankMap-World.png. The map shades the whole area within the national borders of each country with the colors defined in the legend below. NOTE: This map does not include the Slavic language spoken in Greece.
Left to right: 3x AA to D parallel battery converter with rechargeable NiMH AA-size batteries inserted. MY DAY vintage flashlight. It uses 1.5 V D-size batteries. Sofirn SP36 flashlight.  It features a 5 V 2 A USB-C charging port to load 3.7 V 18650 rechargeable lithium-ion batteries.
English: Left to right: A 3x AA to D parallel battery converter with rechargable NiMH AA-size batteries inserted. MY DAY vintage flashlight made in Czechoslovakia. It uses three 1.5 V D-size batteries as power supply and was converted from an incandescent light bulb to a much more powerful white-light-emitting diode (LED) that produces about 270 lm of luminous flux. The user can adjust the relative position of the light source and reflector, giving a variable-focus effect from a wide floodlight to a narrow beam. A mechanical side-mounted slide switch provides control allows the light to be off or left on for an extended time. The slide switch also features a position for intermittent use or signalling by pressing down on it. Sofirn SP36 flashlight made in China. It features a 5 V 2 A USB-C charging port to load three a 3.7 V 18650-type lithium-ion batteries. If necessary, the flashlight can also be powered with one or two batteries. The quadriled torch has four CREE XPL2 5350 – 5700K LEDs that can be ramped by the electronic control button to produce from 0.5 lm up to 6,000 lm of luminous flux. The user interface is fully programmable and can be customized using the backlit electronic control button on the side.
Un grafico che rappresenta il tasso di produzione delle coppie elettrone-positrone rispetto alla massa a riposo (in GeV). Il picco apparente attorno a 6 GeV venne inizialmente identificato come una nuova particella[1] che venne soprannominata Oops-Leon quando poi risultò non esistere.
The Citroën Racing/Total team won the Manufacturer title five races before the end of the season, with a Citroën C-Elysée WTCC 1-2-3-4 at the race of Shanghaï (from left to right: Yves Matton director of Citroën Racing, Ma Qing Hua, J-M López, Yvan Muller and Franz Engstler for 'TC2')
English: 2014 WTCC Shanghai Race 1 Podium with José María López, Ma Qing Hua, Yvan Muller, Yves Matton and Franz Engstler
Процессинг и презентация антигена при участии MHC-II. A — чужеродный белок (антиген); B — эндосома; C — лизосома; D — поздняя лизосома/эндолизосома; E — эндоплазматический ретикулум; F — аппарат Гольджи; G — обмен антигена с помощью CLIP; H — презентация антигена на клеточной мембране
Depiction of the Battle of Nauvoo by C.C.A. Christensen, which occurred from June 10, 1844 to September 16, 1846. The Nauvoo Legion was ordered to stand down by the church elders and not take part in the armed defense but withdrawal of the Saints from Nauvoo for the long trip to Utah.
"The Battle of Nauvoo" by C.C.A. Christensen
L'épave d'un Blohm & Voss BV 138 présentée au Musée national des sciences et de la technologie (Danmarks Tekniske Museum) à Elseneur, au Danemark. Le longeron d'aile est posé sur l'avion dans la même position que lorsque l'épave a été découverte dans l'Øresund, au large de Copenhague.
English: The wreck of a Blohm & Voss BV 138 at display at the National Museum of Science and Technology (Danmarks Tekniske Museum) in Elsinore, Denmark. The wing spar is poised over the aircraft in the same position as it was, when the wreck was discovered in The Sound, off of Copenhagen.
Torre de bori de lo "chuego d'escaques de Carlos Magno", provinient d'Italia y de lo sieglo XI. En francés antigo y dica zaguers de lo sieglo XVII la torre de los escaques se deciba roc, palabra d'orichen persa transmesa por l'arabe y que se relaciona con lo castellán moderno enroque.
Français : Échiquier dit de Charlemagne, quadrige (tour), ivoire d'éléphant, XIe siècle, Italie méridionale, trace de peinture, d'un ensemble de 16 pièces conservées dans le trésor de Saint-Denis - Hauteur environ 8 cm - Cabinet des médailles, Paris, n° Inv 305 à 323
Frank H. Winter with then US Vice President Hubert H. Humphrey, on 16 March 1966, in Washington, D.C.  The occasion was the Ninth Annual Robert H. Goddard Dinner, sponsored by the National Space Club, during which Winter was presented with the Robert H. Goddard Historical Essay Award.
English: Frank H. Winter with then Vice-President Hubert H. Humphrey, on 16 March 1966, in Washington, D.C. Ninth Annual Robert H. Goddard Dinner, sponsored by the National Space Club, during which Winter was presented with the Robert H. Goddard Historical Essay Award.
From Paludan's source: "In this mural foreign ambassadors are being received at court. The two elegantly clad figures on the right are from Korea, the bare-headed, large-nosed figure in the center is an envoy from the west. Mural from Li Xian's tomb, Qianling Mausoleum, Shaanxi, 706."
From Paludan's source: "In this mural foreign ambassadors are being received at court. The two elegantly clad figures on the right are from Korea, the bare-headed, large-nosed figure in the centre is an envoy from the west. Mural from Li Xian's tomb, Qianling, Shaanxi, 706."
Первая почтовая марка СССР на односторонней почтовой карточке с оригинальной маркой (ЦФА [ИТЦ «Марка»] № 11), посвящённой 50-летию сельскохозяйственной и кустарно-промышленной выставки и юбилейной выставке на ВДНХ. Специальное гашение: 19.08 — 15.10.1973, Москва, отделение связи И-222
Русский: СССР, 1973. Маркированная почтовая карточка с оригинальной маркой. "50-летие Первой всероссийской сельскохозяйственной и кустарно-промышленной выставки. Юбилейная выставка на ВДНХ" (Каталог ЦФА №11). Марка: Монумент "Рабочий и Колхозница"; монумент "Космос"; индустриальные сооружения. Иллюстрация: Первая почтовая марка СССР "Жнец". Художник А. Аксамит. Специальное гашение: 19.08 - 15.10.1973, Москва, отделение связи И-222English: USSR, 1973. Postal card with commemorative stamp. "The 50th Anniversary of the First All-Russian agricultural and handicraft industrial exhibition. Anniversary Exhibition at VDNKh" (Catalogue CPA №11). Stamp: Monument "Worker and Kolkhoz Woman"; monument "Space"; industrial buildings. Illustration: The first postage stamp of the USSR "Reaper." Painter A. Aksamit. Special cancellations: 19.08 - 15.10.1973, Moscow, post office I-222
Marshall arrived as a pupil at Oundle School in north-eastern Northamptonshire in the summer term of 1924 and left in May 1928. He returned  'in a magisterial capacity' – though he had wanted to pursue a theatrical career – in 1931. Later he decided that teaching was a kind of acting.
English: Oundle School clositers viewed from the spire of St. Peter's Church
Güte von verbundenem und unverbundenem t-Test in Abhängigkeit von der Korrelation. Die simulierten Zufallszahlen entstammen einer bivariaten Normalverteilung mit einer Varianz von 1 und einer Differenz der Erwartungswerte von 0,4. Das Signifikanzniveau beträgt 5 % und die Fallzahl 60.
Deutsch: Güte von verbundenem und unverbundenem t-Test in Abhängigkeit von der Korrelation. Die simulierten Zufallszahlen entstammen einer bivariaten Normalverteilung mit einer Varianz von 1 und einer Differenz der Erwartungswerte von 0,4. Das Signifikanzniveau beträgt 5%.
Tomb of two Sir Edward Littletons, father and son. East wall of north chancel aisle. Lower stage: Sir Edward Littleton (d. 1610) and his wife, Margaret Devereux. Upper stage: Sir Edward (d. 1629), and his wife, Mary Fisher. Their son, also Sir Edward, became the first baronet in 1627.
English: St. Michael and All Angels parish church, Penkridge, Staffordshire: Jacobean tomb of two Sir Edward Littletons, father and son. East wall of north chancel aisle. Lower stage: Sir Edward Littleton (died 1610) and his wife Margaret Devereux. Upper stage: Sir Edward (died 1629), and his wife Mary Fisher.
Psique se acerca con la lámpara al lecho donde duerme Cupido, dibujo sobre papel amarillento verjurado; lápiz negro, pluma y tinta negra, 206 x 270 mm, Madrid, Biblioteca Nacional de España.[7]​ Dibujo preparatorio para las pinturas de la galería del Cierzo del Palacio Real de Madrid.
Español: Psique se acerca con la lámpara al lecho donde duerme Cupido, dibujo sobre papel amarillento verjurado; lápiz negro, pluma y tinta negra, 206 x 270 mm, Madrid, Biblioteca Nacional de España
Светофор SN109. На рисунке а схема падения солнечных лучей на светофор. На рисунке б красный сигнал, неосвещённый солнцем; на рисунке в показано, как приблизительно выглядел красный сигнал при падении на него солнечных лучей. На рисунке г жёлтый сигнал и его расположение на светофоре.
Русский: Светофор SN109.
Tượng Giáo hội Luther. Nó nằm trong Worms. Đó là bức tượng Giáo hội Luther cao ở trung tâm. Trong bức tượng Zwingly của Zurich, ông tự trang bị một thanh kiếm, trong bức tượng này, chính Luther không có một thanh kiếm và Friedrich Kenko, người bị kềm chế bên cạnh được trang bị vũ khí.
Deutsch: Lutherdenkmal in Worms
Адыгея һәм Кубань райондары башлыҡтарының хәрби сборында, 9-сы мотоуҡсылардивизияһы, 1996. Майкоп. Уртала Адыгея Республикаһы Президенты Джаримов, Аслан Алиевич, уңдараҡ генералдар: СКВО ғәскәрҙәре Командующийы А. В. Квашнин, уның урынбаҫарҙары В. Г. Казанцев, Л.Шатворян, А. Дорофеев.
Русский: На военном сборе глав районов Адыгеи и Кубани в 9-й мсд.1996. Майкоп. В центре Президент РА Джаримов Аслан Алиевич правее генералы: Командующий войсками СКВО А. В. Квашнин, заместители командующего войсками СКВО В. Г. Казанцев, Л.Шатворян, А. А. Дорофеев.
"Microphone" coherer detector from 1909 similar to one Pickard discovered rectification with, widely used in the first receivers.  It consists of a steel needle resting on two carbon blocks. A semiconducting corrosion layer on the steel may have been responsible for the rectification.
English: Photo of a carbon detector or "microphone detector" from 1909, a primitive coherer radio wave detector used in the first radio receivers. It was used from about 1900 to 1910 to receive Morse code radiotelegraphy transmissions from the first spark radio transmitters . The microphone detector was invented by David Edward Hughes, who stumbled on radio wave communication in 1879 while he was experimenting with carbon microphones. It consists of a steel needle resting across two sharp edged carbon blocks. One carbon was connected to the aerial and the other was connected to ground, so the radio waves from the antenna were applied across the needle contact. With no radio signal the device had a large resistance (megohms) but the radio wave altered the steel-carbon contact causing its resistance to drop. An earphone in series with a battery was connected across the carbons, so when the needle conducted electricity it made a hissing noise in the earphone. Greenleaf Whittier Pickard first observed radio wave rectification in 1902 with a similar detector. A semiconducting layer of corrosion on the needle which caused the device to act like a diode may have been responsible for the rectification. This was the first semiconductor diode. Information from Douglas, Alan (April 1981). "The Crystal Detector". IEEE Spectrum 18 (4): 64–69. DOI:10.1109/MSPEC.1981.6369482. ISSN 0018-9235.