context: The artistic accuracy of Sargent in the image of the events taking place before his eyes can be confirmed only by looking at the well-known photograph “World War I: Gas Attack”, dated April 10, 1918, which shows the blinded soldiers walking in a convoy to the dressing station near Bethune during German "spring offensive" [10] [27] [28]. The importance of gas attacks from a military strategic point of view was not so much in the physical weakening of people, but in the fact that the gas blinded and visually disoriented its victims, who fell into the thickness of impenetrable clouds and vapors through which nothing could be seen [11]. Since 1914, armies that resorted to killing, wounding and mutilating their enemies began to strive also to suppress the feelings of the enemy and thereby reduce their ability to fight effectively. Armed with a new arsenal of destructive devices, such as tanks, machine guns, fighters, aerial bombs, searchlights, flashes, barbed wire and toxic gases, they tried to achieve this goal in all unthinkable and indescribable ways [11]. Of these new tactics affecting the senses, gas was perhaps the most mysterious and terrifying. Invented at the end of the 19th century and prohibited by the Hague Convention of 1899, toxic gas was first used on April 22, 1915 during the Battle of Ypres in Belgium. Supporting the advancement of their infantry, the Germans launched greenish clouds of gaseous chlorine onto British, Canadian and French troops unprepared for this, which caused panic and chaos, and then their flight from the battlefield [11]. After that, gas began to be used everywhere by all parties to the conflict, causing extensive injuries and burns to soldiers when spraying, as well as destroying nearby vegetation and poisoning the land affected by toxic substances for many years [1] [29] [30]. At the same time, the productivity of its use fell due to the lack of a proper moment of surprise for the attack and the widespread distribution of gas masks [11]. At the end of September 1918, during the collection of materials for work near Peronna, Sargent fell ill with the flu, after which he spent a week next to wounded soldiers in a hospital near Roisel [31]. Impressed by the field hospital he saw with his own eyes, crowded with groaning soldiers suffering from the effects of a gas attack, Sargent decided to move away from excessive heroism and change the theme of the future picture [10] [15] [32]. After four months at the front, at the end of October of that year, Sargent and Tonks returned to the UK [10] [33]. Sargent discussed the plot he had changed with members of the Memorial Committee so that the picture fits into the dimensions of the Memorial Hall [4]. At the same time, he expressed doubt about the possibility of high-quality work of this magnitude, and in a letter to Alfred Jockney on October 4, 1918, noted that it turns out “a picture in a terribly long strip ... I think that the picture would be much better and it would be much less difficult to write if it were twice less ”[4]. Having received permission to change the subject, Sargent intended to express on the canvas his negative attitude to the previously proposed story about a military partnership [1] [34]. In the winter of 1918-1919, in his studio in Fulham, Sargent continued to work on the painting, having at hand sketches made on the battlefield, as well as detailed sketches of the bodies of professional sitters [4]. While posters from World War I advocated recruitment to the front and the purchase of military loans, Sargent’s numerous drawings show pain and suffering, and therefore another war [32]. So, the nurse Vera Britten, who worked at the dressing station, wrote in a letter home in 1917: “Now we have many victims of gas poisoning, who came a day or two ago: there are only 10 people in our room. I think that those people who write so eloquently that this is a holy war, and speakers who say so verbose that the war will last as long as necessary, will not see at least one victim - and will not tell anything about dozens other victims in the early stages of mustard gas poisoning - these poor creatures are all burnt and covered with large festering blisters, blinded by their eyes - when temporarily [sic], and when forever - all sticky and stuck together, and everyone is fighting for life, their voices are whispers, they say that and pharynx stick together, and they know that they will suffocate "[11] [35]. Sargent completed work on the painting in March 1919, after which this rectangular canvas nine feet high and twenty feet long, which resembles a widescreen movie in format, was first exhibited under the name "Gassed" in Royal Academy in London [36] [11] [37] [1] [6]. For his work, Sargent received only 300 pounds, while William Orpen was paid only 3,000 pounds for the painting “Signing the World in the Mirror Hall”, a record amount for a work of art during the war [38]. Sargent's canvas was recognized by the Academy as a "picture of the year" [25] [39].
question: What is the length of the film "Poisoned by gases"?
answers.text: twenty feet