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.
Steamboat History. The steamboat represented an important phase in the development of shipping. Before the steamboat was invented, boats were powered by sail power. From the mid-19th to the mid-20th century, steamboats were the most important type of boats for transportation, trading and warfare.o start the process, water is fed to a boiler that heats it up until it produces steam. The steam is then fed into a piston cylinder. It pushes the piston up to the top of its stroke. When it reaches the top, a valve is opened in the side of the cylinder to vent out the steam.