Which of the following computing devices did not exist in the pre-computing age to the 19th century?

The ENIAC was the first electronic general-purpose computer that was built in the mid-1940s, long after the pre-computing age and the 19th century. Therefore, the answer is ENIAC. - Napier's bone: A manual calculating device invented by John Napier in the early 17th century. - Abacus: A manual calculating device that has been used for thousands of years, dating back to ancient times. - Slide rule: A mechanical analog computer used for multiplication, division and other mathematical calculations. It was widely used from the 17th to the late 20th century. So, the computing device that did not exist in the pre-computing age to the 19th century is ENIAC.