BSHM-LMS De Morgan Day

T he BSHM was co-sponsor of this De Morgan meeting commemorating the 150th anniversary of the setting up of the London Mathematical Society (LMS). Augustus De Morgan was its first president, the society inspired by students A C Ranyard and George De Morgan, the ‘mathematical son’ of Augustus. The meeting began with a welcome from the two current presidents, Terry Lyons (for the LMS) and Philip Beeley (for the BSHM). It was fitting that the De Morgan meeting took place in ‘his’ building, located not more than half a mile from the place where the inaugural meeting took place, the meeting at which he presided. We were reminded of the traditions of the society when two participants signed the LMS book and formally became members. Following an overview of De Morgan’s life, we were treated to lectures on aspects of his life in mathematics and logic. He was a great letter writer, and there were talks on his correspondence with George Boole and Ada Lovelace, and lectures on his role in setting up the LMS, his writing of the Budget of Paradoxes and his influence on modern thought. As an introduction, Adrian Rice spoke on De Morgan’s life and work. As he noted De Morgan is perhaps best remembered for the laws that bear his name: the famous De Morgan laws linking union, intersection, and complement of sets, the laws which appear in just about all modern textbooks. That De Morgan was the first discoverer of these is open to historical dispute, and given this tenuous link, what else should De Morgan be remembered for? In recent decades, research has shed light on forgotten aspects of his life and associations giving us a more complete picture of the range and diversity of his mathematical activities, and not least his personality. He always insisted on being De Morgan (and not de Morgan), declined membership of the Royal Society, and, in an age when the Anglican Church was all powerful, described himself as a ‘Christian unattached’. As the meeting progressed De Morgan emerged as a man of singular character. The lecture by Chris Hollings delved into De Morgan’s correspondence with Ada King, Countess of Lovelace, the daughter of Lord Byron. Previous readings of this correspondence, in which De Morgan adopted the role of teacher, have resulted in wildly differing assessments of her mathematical abilities. Here it was argued that she lay somewhere around half-way between the extremes of ‘hopeless’ and ‘mathematical genius.’ Of De Morgan’s publications on general mathematics, his Budget of Paradoxes was best known in his day, and it is still a good read. It was a natural outgrowth of his book reviews published in the weekly London-based literary magazine, The Athenæum. Sloan Despeaux’s talk included sample episodes associated with the amateurs and cranks of Victorian England bound together for all to enjoy. Top of the pile must be James Smith, a Liverpool merchant and Arch-Paradoxer, the king of the circle-squarers. He spent much of his retirement insisting that the true value of p was