But neither 30 years of 30 centuries affect the clearness or the charm of geometrical truths. Such a theorem as “The square of the hypotenuse of a right angled triangle is equal to the sum of the squares of the sides.” Is as dazzlingly beautiful now as it was on the day when Pythagoras first discovered it and celebrated its advent, it is said, by sacrificing a hectacomb of oxen – a method of doing honour to science that has always seemed to me slightly exaggerated and uncalled for. Even in these degenerate days, marking the epoch of some brilliant discovery by inviting a convivial friend or two over for a beefsteak and a bottle of wine. But a hectacomb of oxen! It would produce a quite inconvenient supply of meat.