A larger audience than in usual at Maths and Physics Society meetings gathered on Thursday evening to discover what a number really was. Amongst the regular mathematicians and physicists were a number of philosophers attracted by the provocative title "What is a Number?" or by the prospect of a free supper. Professor Campbell started with a general consideration of the rules of algebra for the natural numbers 1, 2. 3, 4 ..., and from these developed the classes of the Integers, the Rational Numbers. Irrational Numbers and finally the Complex Numbers.

The lecture was by this time somewhat technical and primarily a consideration of properties of numbers arising from the postulates.

The ideas and methods were simple enough, but the satisfactory and sophisticated method of presenting them puzzled some. As the lecturer said, "an ordinary class would howl me down." The concepts of complex and hyper-complex numbers extended the question to a field which was new to the philosophers. Clearly far more was being considered than the question of 1. 2. 3 . . .

The Professor then went to the origins of the number theory and with an apprehensive glance at Professor Hughes, prominent in the front row, explained what sets were. He put the persons in the room in one-to-one correspondence to dairy cows and matches in a match box. (There should be 50 but there were only 46—Dr. Campbell. PhD. (Edin) counts them).