John Cronin served a traditional apprenticeship as a watchmaker and, after winning several awards, was elected a Fellow of the British Horological Institute. Later, he gained a history degree and taught history for 25 years. After retiring from teaching, he set up a business in Horological Conservation and in 1994 was awarded a Fellowship by Gift of the Worshipful Company of Clockmakers. He has written many articles and two other books on horology.