Percy Edwin Ludgate (2 August 1883 – 16 October 1922) was an Irish amateur scientist who designed the second analytical engine (general-purpose Turing-complete computer) in history.

[5] He studied accountancy at Rathmines College of Commerce, earning a gold medal based on the results of his final examinations in 1917.

[3] It seems that Ludgate worked as a clerk for an unknown corn merchant, in Dublin, and pursued his interest in calculating machines at night.

Ludgate's engine also used a mechanism similar to slide rules, but employing unique, discrete "Logarithmic Indexes" (now known as Irish logarithms),[7] as well as a novel memory system utilizing concentric cylinders, storing numbers as displacements of rods in shuttles.

[9] Since then, further investigation is underway at Trinity College, Dublin under the auspices of the John Gabriel Byrne Computer Science Collection.