Charles Babbage is world famous as the designer of the first programmable mechanical computer in 1834. Babbage’s “analysis engine” was designed to solve equations by simply turning a wheel and turning a cog. 50 gears, each 2.5m in diameter, represent each number. Babbage envisioned his system of 1,000 memories with 50,000 gears. To hold them all he needed a 150 m frame. It’s longer than his pitch of a full-sized football.
Almost a century later, on the eve of World War I, a prominent Irishman born in Skibbereen and then living in Dublin presented a very different design of a programmable mechanical computer. Percy Ludgate suggested using 21 notched rods grouped into shuttles for each number. Containing a set of shuttles, he can present a set of numbers from the storage system to the arithmetic unit by rotating two concentric rings. A computing unit mechanically sensed how far each rod set protruded from the shuttle.
What struck me most was that Ludgate’s design was as compact as a small refrigerator. But like Babbage’s giant, the Ludgate machine has yet to be built.
After working as a clerk at a corn merchant, Ludgate spent evenings investigating at Drumcondra’s home.he published his design in the scientific proceedings At the Edinburgh Conference on the eve of World War I, Ludgate distinguished between specialized machines, each limited to solving only a limited set of equations, and Babbage’s unique general-purpose design, which was programmable. bottom. for any equation. Almost incidentally, Ludgate then states that he himself developed his second design of his machine, which is universally programmable, but this is quite different from his Babbage design.
With the advent of war and the Spanish flu, Ludgate’s work was forgotten. He died in his 1922 from complications of pneumonia.
His work was rediscovered in the 1970s by Brian Randell of Newcastle University and Brian Coghlan of Trinity College Dublin. They researched Ludgate’s design details and family genealogy. This book offers a fascinating collection of their investigative work, as well as Rudgate’s original papers. Percy Ludgate, a brilliant mathematician and engineer, deserves to go down in world history as his designer of Ireland’s first computer.
