By the 40s of the 19th century, some American gun mechanics began to manufacture firearms with optical sighting devices. In 1848 Morgan James of New York designed a tubular sighting device of the same length as the barrel, which was fitted with a glass lens in the rear half and had 2 crosshairs for aiming. Later, similar sighting devices were applied in the American Civil War. But the truly practical scope was born in 1904, developed by Carl Zeiss of Germany and used in World War I. In World War II, the scope began to mature.