1 teaspoon vanilla extract. 1 large egg. Lightly grease a doughnut (or muffin) tin and preheat the oven to 350F. Sift the flour, cocoa powder, baking powder and baking soda, and then whisk in the sugar, nutmeg and salt.
steam engine. An engine in which the energy of hot steam is converted into mechanical power, especially an engine in which the force of expanding steam is used to drive one or more pistons. The source of the steam is typically external to the part of the machine that converts the steam energy into mechanical energy.
In 1852, the first flight of a steam-powered airship took place. Future iterations of the steam engine also came to define travel, as trains, boats and railways adopted the technology to propel passengers into the 20th century. [See also: How the Steam Engine Changed the World] Follow Elizabeth Palermo on Twitter @techEpalermo, Facebook or Google+.