Eastern Front
Romania: Battle Of Bucharest: In Romania, Central Power troops cross the lower Arges River, which brings the capital Bucharest in range of artillery guns. Falkenhayn then signs 3-day armistice allowing Bucharest‘s evacuation (arsenal and forts blown up on December 4).
Carpathians: Severe fighting in Carpathian and Moldavian Valleys; Russians push up the Trotus.
Romanian retreat south-east; heavily beaten by Mackensen on Lower Arges.
Bulgarians repulse Russian assaults in the Dobruja.

Southern Front
Serbia: Serb Drina Division captures Gruniste east of Crna, then Staravina on December 4.
Greece: Outrages against Venizelists at Athens; 1,300 French troops landed at Piraeus, but re-embarked.

Naval and Overseas Operations
Funchal (Madeira) bombarded by German submarine U-38, (see December 12th, 1917, when U-156 repeats it), sinking 2 ships in harbor, and the French sloop Surprise off port.
British and French Governments conclude agreement (the "Clementel Agreement"): (1) to unite British ships in French service to those already employed; (2) to co-ordinate Allied tonnage; (3) to create inter-allied bureau to centralise charter of neutral shipping (see January 6th, November 3rd, and December 3rd, 1917).

Political, etc.
Austria-Hungary: Emperor Charles I of Austria visits the Austro-Hungarian Army headquarters for the first time since ascending the throne.
Russia: Russian Premier Trepov promises that after the war, Russia will create a new Kingdom of Poland that encompasses all Polish territory.
Germany: Socialist members of the Reichstag denounce German forced labor and deportations of Belgian civilians.
United Kingdom: Admiral Sir Henry Jackson, First Sea Lord, Great Britain, resigns (see 4th, and May 28th, 1915).
David Lloyd George and other Conservative Cabinet members demands Premier Asquith to resign, or else they would resign. Mr. Asquith decides on re-construction of Government.
Wage dispute in South Wales settled in favor of miners.
Mexico: Pancho Villa retreats from the city of Chihuahua, Mexico after sacking it. Mexican government troops later retake the city.

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On the kinkometer, my kink measures as a sine wave.