The Lewis gun is a type of light machine gun that was first developed in the early 20th century. It was designed by American inventor Isaac Newton Lewis and became widely used during World War I. The gun is notable for its distinctive circular magazine and its ability to fire .303 British ammunition, making it effective for infantry support. The Lewis gun features a gas-operated mechanism, allowing for a high rate of fire. It was used by various military forces, including the British and American armies, and remained in service through World War II. Its lightweight design made it easier for soldiers to carry and operate in the field.