The Rev Nicholas Callan, a pioneering Irish scientist and inventor, is among those featured in a new series of six stamps by An Post. The stamps, part of a millennium series celebrating "discoveries", also feature Galileo, Einstein, Marie Curie, Thomas Edison and the Birr telescope.
The history of science is full of stories of people who discover or invent something new, only for the credit ultimately to go to somebody else. So it was with Callan.
Nicholas Callan (1799-1864) was born in Co Louth, ordained a priest in 1825 and later became professor of natural philosophy (science) at St Patrick's College, Maynooth. His main interest was electricity and he experimented with batteries, magnets, motors and coils, all paid for from his personal funds. In 1836 he invented the induction coil, an early transformer, though now the credit usually goes to Heinrich Ruhmkorff, despite his coil not appearing until 1851. Callan's largest coil was demonstrated in London in 1837; it produced a 15-inch spark and an estimated 600,000 volts - the highest man-made voltage known at the time.
Something of a showman, Callan would measure the strength of his devices by seeing how many people holding hands could absorb the shock. On one occasion he electrocuted a turkey. He made many enormous magnets, one of which, seven feet high and capable of lifting two tons, featured in the Encyclopaedia Britannica (8th edition). He used his magnets and motors to drive small trolleys around his laboratory and when the first Irish railway opened in 1834, suggested electricity be used to drive the trains.
Various experiments with chemical batteries led him to discover a way to prevent iron rusting by coating it with a lead-tin mix.
The museum in Maynooth College contains an extensive collection of Callan's equipment and inventions. It will reopen to the public later this spring.