Percy Edwin Ludgate

Designer of an Analytical Engine, Ludgate helped advance calculators by expanding Charles Babbage's design for the first programmable computer. An Irish accountant working alone in Dublin, he was unaware of Charles Babbage's designs, although he later went on to write about Babbage's machine. Ludgate's engine used multiplication as its base mechanism, unlike Babbage's, which used addition, and his engine used rods similar to slide rules. Its precise mechanism is unknown, as only written accounts of the engine survive that do not detail its workings.

Ludgate was one of a few independent workers in the field of science and mathematics, and his inventions were worked on outside a lab and only part-time. His design featured several novelties, including a method of implementing multiplication referred to at the time as "Irish logarithms."

Little is known about his life, as his only records are his scientific writings. In 1991, a prize for the best final year project in the Moderatorship in computer science course at Trinity College Dublin — the Ludgate Prize — was instituted in his honor.