Cute Young Curly Brunette Girl Outside In The Nature With A Baguette And Tomatoes

Deck ovens use steam injection, through various methods, to create the proper baguette. The oven is typically well over 205 °C (400 °F). The steam allows the crust to expand before setting, thus creating a lighter, more airy loaf. It also melts the dextrose on the bread's surface, giving a slightly glazed effect.
An article in The Economist states that in October 1920 a law prevented bakers from working before 4am, making it impossible to make the traditional, round loaf in time for customers' breakfasts. The slender baguette, the article claims, solved the problem because it could be prepared and baked much more rapidly. Unfortunately, the article is not sourced and at any rate France had already had long thin breads for over a century at that point.
The law in question appears in fact to be one from March 1919, though some say it took effect on October 1920: "It is forbidden to employ workers at bread and pastry making between ten in the evening and four in the morning." The rest of the account remains to be verified, but the use of the word for a long thin bread does appear to be a twentieth century innovation.