24. Dezember

Baldwin of Boulogne left the main army for the Armenian city of Edessa, was adopted by its ruler Thoros, and took over when a mob killed him. It was the first crusader state and the first to fall, a mostly Armenian county across the Euphrates.

While Count Joscelin II was away, Zengi, atabeg of Mosul and Aleppo, mined the walls and stormed the city after a month’s siege. The first crusader capital to fall, it made Zengi a champion of the jihad and brought on the Second Crusade.

Richard Trevithick’s high-pressure steam carriage carried several men up Camborne Hill on Christmas Eve. A few days later the crew left it burning in a shed while they dined at an inn, the water boiled away and it burned out.

The convention’s declaration complained that the free states had united to elect “a man to the high office of President of the United States, whose opinions and purposes are hostile to slavery”.

Commissioned for the Khedive Isma’il Pasha’s new opera house. The sets and costumes, made in Paris, were trapped by the Prussian siege, and the premiere slipped by most of a year. Verdi stayed in Italy and saw to the European premiere at La Scala in February 1872.

Reginald Fessenden later wrote that on this night he played O Holy Night on the violin and read from Luke to ships at sea. The only account is his own, written in 1932, and historians have found no contemporary report of it. That he sent voice by radio from Brant Rock around then is not in doubt.

The Ross Sea party’s ship, bought from Douglas Mawson, under Aeneas Mackintosh. Its job was to lay food depots as far as the Beardmore Glacier for Shackleton’s crossing party, due to arrive from the Pole.

Walking in the snow, Meitner and her nephew Otto Frisch pictured the nucleus as a wobbling drop that splits in two. On a scrap of paper they reckoned the energy at about 200 million electronvolts, the mass lost times c², just what the fragments’ repulsion would give.

The first people to leave Earth orbit, sent to the Moon months early partly for fear of a Soviet flight around it. On Christmas Eve Bill Anders photographed the Earth rising over the lunar horizon, Earthrise, and the crew read from Genesis on live television.

Moscow sent its army in to save a communist government it did not trust. It stayed nine years against mujahideen armed by the United States, Pakistan and Saudi Arabia. About 15,000 Soviet soldiers died. Estimates of Afghan deaths run from about one million to two million, and some five million…

Its closest pass yet, about 6.1 million km from the Sun’s surface at around 690,000 km an hour, the fastest a human-made object has ever moved.