World War 1
Worldwar1.com: Trenches on the Web: Big Guns of the Great War
This site from Trenches on the Web gives an overview of the different types of artillery used in World War I. Provides several thumbnail images of rail guns, howitzers and other forms of artillery, which can be enlarged by clicking on them.
American Association of Physics Teachers
Com Padre Digital Library: Open Source Physics: Rail Gun Model
Simulate the movement of a rail gun in this interactive model. Learn how a magnetic field is generated by running electrical current through long rods that accelerates a current-carrying cross-rod.