World War I were used by the British Army, the French Army and the German Army. 1912 - Articulated trams, invented and first used by the Boston Elevated Railway. Science In 1916, Albert Einstein's theory of general relativity. Max von Laue discovers the diffraction of x-rays by crystals. In 1912, Alfred Wegener puts forward his theory of continental drift. Economics In the years 1910 and 1911, there was a minor economic depression known as the Panic of 1910–11, which was followed by the enforcement of the Sherman Anti-Trust Act. Popular culture Flying Squadron of America promotes temperance movement in the United States. Edith Smith Davis edits the Temperance Educational Quarterly. The first U.S. feature film, Oliver Twist, was released in 1912. The first mob film, D. W. Griffith's The Musketeers of Pig Alley was released in 1912. Hollywood, California, replaces the East Coast as the center of the movie industry. The first crossword puzzle was published 21 December 1913 appearing in The New York World newspaper. The comic strip Krazy Kat begins. Charlie Chaplin débuts his trademark mustached, baggy-pants "Little Tramp" character in Kid Auto Races at Venice in 1914. The first African American owned studio, the Lincoln Motion Picture Company, was founded in 1917. The four Warner brothers, (from older to younger) Harry, Albert, Samuel, and Jack opened their first major film studio in Burbank in 1918. Tarzan of the Apes starring Elmo Lincoln is released in 1918, the first Tarzan film. The first jazz music is recorded by the Original Dixieland Jass Band for Victor (#18255) in late February, 1917. The Salvation Army has a new international leader, General Bramwell Booth who served from 1912 to 1929. He replaces his father and co-founder of the Christian Mission (the forerunner of the Salvation Army), William Booth. Sports 1912 Summer Olympics were held in Stockholm, Sweden. 1916 Summer Olympics were cancelled because of World War I. Literature and arts Below are the best-selling books in the United States of each year, as determined by The Bookman, a New York-based literary journal (1910 - 1912) and Publishers Weekly (1913 and beyond). 1910: The Rosary by Florence L. Barclay 1911: The Broad Highway by Jeffery Farnol 1912: The Harvester by Gene Stratton Porter 1913: The Inside of the Cup by Winston Churchill 1914: The Eyes of the World by Harold Bell Wright 1915: The Turmoil by Booth Tarkington 1916: Seventeen by Booth