Read history

26 December 1898: a note read to the Academy

At the 26 December 1898 session of France's Académie des Sciences in Paris, Henri Becquerel presented a note by Pierre Curie, Marie Curie and Gustave Bémont. It described a strongly radioactive substance pulled from pitchblende that behaved chemically almost exactly like barium.

Repeated fractional separation made the barium-rich chlorides more radioactive, not less. Activity that started at 60 times that of metallic uranium climbed, through the separations, to 900 times that of uranium.

Three authors, and a spectral line from a fourth man

Gustave Bémont was a coauthor, not an assistant — the chemist who worked on separating the barium-like substance. Popular accounts routinely drop him and leave only Marie and Pierre.

Eugène Demarçay, who was not an author at all, supplied independent spectral evidence. He had seen an unfamiliar spectral line in the material, and it strengthened in step with the radioactivity; together with the fractionation results, that supported the hypothesis of an unknown element rather than unusually active barium.

What the paper did not claim

The language was deliberately provisional. The authors concluded that the substance appeared to contain a new element and proposed the name radium; they did not claim to have isolated it.

The 1898 material was overwhelmingly barium, and the name plus the supporting evidence was all that entered the Academy's published record that day. Proving radium's chemical individuality and isolating it required several more years.

A receipt stamp dated 14 March 1900

The journal of the German Botanical Society recorded 14 March 1900 as the receipt date for Hugo de Vries's manuscript "Das Spaltungsgesetz der Bastarde" — "The Law of Segregation of Hybrids". It ran in volume 18, pages 83–90.

In that manuscript de Vries stated two propositions about dominance and about the separation of antagonistic characters during pollen and egg formation, then acknowledged that Mendel had already stated their essentials for peas.

So 14 March is a manuscript-receipt date. It is neither the paper's publication date nor a documented date on which de Vries suddenly discovered Mendel's laws.

Two documents, twelve days apart, neither a discovery

The competing date is 26 March 1900, when de Vries's short French note "Sur la loi de disjonction des hybrides" appeared in the Comptes rendus of the Académie des Sciences, volume 130, pages 845–847. It did not name Mendel.

The two dates therefore belong to two different papers — the longer German one that credited Mendel and the shorter French one that did not. Sources also disagree on when the German paper itself was actually printed, cataloguing it variously in late March or April.

De Vries's own German footnote claimed he encountered Mendel only after most of his experiments were finished, a claim historians have spent decades testing.

The priority race the notes set off

The French note set out de Vries's segregation claim — that antagonistic characters separate during the formation of pollen and egg cells — without naming Mendel, and it was the first version of the result to reach print.

Correns published his own results rapidly after reading de Vries, emphasizing Mendel's priority; Tschermak published pea-crossing work later in 1900.

"Rediscovery by de Vries, Correns and Tschermak" is a traditional shorthand rather than an uncontested account of three independent, simultaneous discoveries — historians dispute the chronology, the independence, and even Tschermak's standing as a rediscoverer.

28 May 1905: surrounded south of the Liancourt Rocks

At dawn on 28 May 1905, Admiral Tōgō Heihachirō's Combined Fleet moved to block the surviving Russian ships' route north. By about 10:30 a.m. it had surrounded Rear Admiral Nikolai Nebogatov's remnant south of the Liancourt Rocks.

Nebogatov surrendered the battleship Imperator Nikolai I, the damaged battleship Oryol, and the coast-defense ships Admiral Apraksin and Admiral Senyavin. The cruiser Izumrud broke through the cordon before the surrender.

Signed aboard Mikasa at 1:37 p.m.

A naval-history account records Russian surrender signals at 10:43 a.m. and Nebogatov signing the instrument of surrender aboard Tōgō's flagship Mikasa at 1:37 p.m.

The morning surrender did not end the day's fighting. Japanese forces sank or captured further ships, and at about 4:45 p.m. the destroyer Byedovy surrendered with the wounded Vice Admiral Zinovy Rozhestvensky and his staff aboard.

Totals that the sources dispute

Tōgō's published report counted about 6,000 Russian prisoners against three Japanese torpedo boats lost, 116 Japanese dead and 538 wounded. A frequently reproduced later Japanese tally gives 117 killed and 583 wounded.

Russian losses vary by account as well; a U.S. Naval Institute account gives 21 ships sunk, 7 captured and 5,045 dead. Contemporary Russian records, on the Julian calendar, date the two days 14–15 May.

What 1906 actually produced

In 1906 Albert Calmette and Camille Guérin published early work titled "Sur la vaccination contre la tuberculose par les voies digestives" — on vaccination against tuberculosis by the digestive routes.

They were studying whether exposure to living bovine tubercle bacilli could protect cattle, and whether administration through the digestive tract could produce immunity.

Some modern histories also place the first treatment of Mycobacterium bovis with ox bile in 1906, describing the altered appearance of the cultured bacilli as the start of BCG development. Bile was initially useful because the bacteria clumped together.

Years of passage, not a year of discovery

No finished human BCG vaccine existed or was administered in 1906. The attenuated strain came out of repeated passage, with transfers to fresh culture roughly every three weeks, reaching 230 passages by 1920.

The first human use came in 1921.

Edmond Nocard had supplied Guérin with the bovine tuberculosis culture from which the BCG lineage ultimately descended.

Which year counts depends on the definition

"First developed" has no single defensible date. Sources variously identify early research in 1900, vaccination publications or bile experiments in 1906, continuous attenuation from 1908, an innocuous strain after years of passage, and first human use in 1921.

The Institut Pasteur and a major microbiological review date the decisive culture and continuous serial-attenuation programme to 1908, with derivation of the original BCG strain spanning 1908–1921.

The discrepancy reflects competing definitions of "development," not a one-day discovery.

Summer 1907, in a Montmartre studio

Picasso finished the canvas sometime during the summer of 1907, in the Bateau-Lavoir building in Montmartre; MoMA catalogues it more specifically as Paris, June–July 1907. No exact completion day is documented. He was 25.

He had worked on it in at least two stages, beginning in the winter of 1906–07. The finished oil compresses five women into a shallow space using angular lines, flattened planes, conflicting viewpoints and deliberately disjunctive styles.

The man he painted out

Hundreds of preparatory drawings and paintings led to the large canvas. Earlier studies included a male medical student entering the scene; Picasso replaced him with a fifth woman.

The sources he drew on cannot be reduced to African masks. MoMA identifies references to European painting alongside African, Iberian, Oceanic, ancient Egyptian, Greek and South Asian sculpture.

Nine years before the public saw it

The work was not publicly exhibited in 1907 and carried no formal title when visitors encountered it in the studio. The name it now goes by was attached around its first public showing, at the 1916 Salon d'Antin.

Some contemporaries called the canvas unfinished because of its abrupt stylistic differences; MoMA notes that later art historians generally treat those differences as integral to the completed work. Its relationship to Cubism is disputed — Kahnweiler called it Cubism's beginning, while other scholars deny that the painting itself is Cubist.

Two patents, two weeks apart

The United States issued Lee de Forest Patent No. 841,387, "Device for Amplifying Feeble Electrical Currents," on 15 January 1907. The application had been filed on 25 October 1906 and described an evacuated vessel with three electrodes, one of them heated.

That was not the clearest patent for the familiar grid Audion. De Forest filed a separate application on 29 January 1907 — the one describing a conducting grid between the heated filament and the plate — which became Patent No. 879,532 on 18 February 1908.

Why the year, not a day

"Invented in 1907" folds three different milestones together. The MIT Museum dates the Audion's invention to the latter half of 1906 and treats 15 January 1907 as the patent milestone.

The two January dates are both real and both partial — a grant and a filing — and the grid patent's grant belongs to 1908. Neither can stand alone as the day the triode was invented.

What the device could actually do

The January filing presented the device chiefly as a more sensitive detector of wireless oscillations, and its stated aim involved a gaseous medium — the opposite of the high-vacuum tubes that later made electronics reliable.

The early Audion was conceived as a detector or amplifier for weak signals, but in its original gas-filled, low-vacuum form it remained crude and unreliable.

Calling it the first practical electronic amplifier is a retrospective description of the improved tube: later engineering, including Harold Arnold's work on the vacuum, was needed before it became robust.

26 May 1908, shortly after 4 a.m.

Drillers at Masjed-e Soleyman in Khuzestan struck a large petroleum reservoir shortly after 4 a.m. on 26 May 1908. Encyclopaedia Iranica describes oil rising perhaps 50 feet above the rig and soaking the drillers.

George Reynolds, the field engineer directing the work, reported oil struck in No. 1 well at a depth of 1,180 feet. The site sits about 80 miles northeast of Ahvaz.

The news left by camel

A camel courier carried word toward the telegraph network, and the security officer Arnold Wilson sent a coded message of his own.

A test flow the following day was estimated at 297 barrels. That was near-immediate evidence the strike was commercially meaningful rather than another minor seep.

Who held the rights that morning

The Anglo-Persian Oil Company did not make the discovery — it did not yet exist. Reynolds worked for the Concessions Syndicate, financed by Burmah Oil, which held the concession Mozaffar al-Din Shah had granted William Knox D'Arcy in 1901.

So no rights changed hands on 26 May; what changed was that a near-abandoned venture now had a demonstrated commercial reservoir. D'Arcy, whose name was on the concession, never visited Persia.

8 April 1911: a transfer test at Leiden

The Leiden University experiment of 8 April 1911 began at 7 a.m., and its principal objective was the first successful transfer of liquid helium into a separate experimental cryostat — not the discovery of a new state. Kamerlingh Onnes arrived when helium circulation began at 11:20 a.m.

The apparatus already contained gold and solid-mercury resistors. The mercury conductor was seven U-shaped glass capillaries connected in series, each with a reservoir intended to keep the frozen mercury from breaking apart during cooling.

Practically zero, at about 3 K

Gilles Holst made the precision resistance measurements, while Gerrit Flim, Cornelis Dorsman and other laboratory specialists handled the cryogenic and temperature work. After measuring mercury and gold at 4.3 K, the team reduced the helium vapor pressure to about 197 mmHg, corresponding to roughly 3 K.

At exactly 4 p.m., the notebook recorded that mercury's resistance was practically zero. The sharply defined transition at 4.20 K came from later experiments — on 26 October the resistance changed from below 10⁻⁶ ohm to 0.1 ohm within 0.01 K.

Two anomalies seen, only one understood

Late that afternoon the team also noted that the helium stopped boiling near the lowest temperature and evaporated instead from a visibly shrinking surface. Historians interpret this retrospectively as the helium lambda transition; the team did not identify superfluid flow.

The often-repeated story of a sleepy apprentice letting the helium warm and causing a dramatic galvanometer swing is contradicted by the notebooks. Kamerlingh Onnes's first report on the resistance result was dated 28 April 1911.

1 January 1912: a late-evening oath at Nanjing

Sun Yat-sen took the oath of office as provisional president at Nanjing on 1 January 1912 — reportedly at about 10 p.m. — and proclaimed the Republic of China and its provisional government. The Nanjing assembly of provincial representatives had elected him unanimously three days earlier, on 29 December 1911.

In his inaugural declaration Sun described the new administration as provisional and committed it to national unity and to government founded on the people's will. Li Yuanhong, the Hubei revolutionary leader, was chosen provisional vice-president.

Two governments in one country

The inauguration created a functioning revolutionary government at Nanjing, and it claimed national authority. The Qing court and Yuan Shikai's government still operated in Beijing.

Yuan retained the principal northern army and went on negotiating with both the revolutionaries and the court. The Qing had not abdicated — that came on 12 February.

Year 1 of the Republic

The new government also reset political time: 1912 became Year 1 of the Republic.

What the date marks is the proclamation and opening of the Nanjing provisional government — not the day Qing authority ceased everywhere, nor the achievement of a unified national government.

The night of 30–31 October 1918

During the night of 30–31 October 1918, soldiers and civilian revolutionaries supporting the Hungarian National Council occupied Budapest's major public buildings, transport junctions, telephone exchange and arms depots, and released political prisoners. The revolution's name comes from the asters placed in soldiers' caps once the imperial insignia were removed.

By the morning of 31 October the police and guards, along with the post, telegraph and railway, had joined or yielded to the movement. Effective power lay with the National Council.

A revolutionary appointed in the king's name

János Hadik abandoned his attempt to form a government. Archduke Joseph, acting for King Charles IV, appointed National Council leader Mihály Károlyi prime minister.

Károlyi built a coalition from the National Council parties — his Independence Party, the Civic Radicals and the Social Democrats. Its ministers swore allegiance to Charles that evening, taking their formal legitimacy from the monarch.

Not bloodless, and not yet a republic

Four soldiers shot the former prime minister István Tisza dead at his Budapest home the same day. The Chain Bridge confrontation three days earlier had left 3 dead and 55 reported wounded.

Hungary did not become a republic on 31 October. The ministers were released from their oath the following day, and the People's Republic was proclaimed on 16 November.

10 September 1919, from 10:00 to 11:15

On 10 September 1919, Allied and Associated plenipotentiaries and the Austrian chancellor Karl Renner assembled at 10 a.m. in the Hall of the Stone Age at the Château de Saint-Germain-en-Laye. Georges Clemenceau opened the session and invited Renner to sign.

Renner signed first, and the Allied and Associated representatives followed — 27 countries signed with Austria. The parties executed the treaty, a protocol, a protocol of signature and associated declarations, and adjourned at 11:15 a.m.

What the 381 articles set out

The treaty defined Austria's borders, recognized successor states, constrained Austrian independence and armaments, and established reparation obligations. Article 120 capped the Austrian army at 30,000 men, including officers and depot troops.

Article 88 neither used the word Anschluss nor prohibited every economic agreement with Germany; it required League Council consent for acts compromising Austrian independence.

Signed is not the same as in force

Austria's National Assembly had authorized Renner on 6 September to accept and sign the imposed terms under protest. The Austrian parliament approved the treaty on 17 October.

Under the treaty's own final clauses it entered into force — and ended the state of war for ratifying parties — on 16 July 1920. The United States signed it and never ratified.

13 August 1920, east of the capital

Soviet forces attacked Warsaw's eastern defences on 13 August 1920, broke through the first Polish defensive line and captured Radzymin during the afternoon.

Radzymin lay only two kilometres behind that first line, making its loss an immediate threat to the capital rather than a Soviet setback.

The Radzymin–Ossów–Wołomin fortifications stood about twenty kilometres east of central Warsaw.

Undecided for three more days

Polish and Soviet forces entered several days of desperate, shifting combat along that line. The Poles recovered Radzymin on 15 August.

Józef Piłsudski was holding a strike force south-east of Warsaw on the Wieprz; his counteroffensive began on 16 August and advanced 45 kilometres on its first day, forcing Mikhail Tukhachevsky's forces into retreat.

Where the battle begins depends who you ask

Norman Davies begins the battle at dawn on 12 August, while Polish official commemorations commonly use the 13 August assault and capture of Radzymin as the start.

The broader Battle of Warsaw extended past 16 August; that date marks the opening of the decisive counteroffensive, not an agreed end.

The 13 August date is securely documented for the fall of Radzymin, but it will not support the claim that the Red Army was defeated that day.