So, standing on the kerb, I brought a number of papers from my pocket and began to turn them over in search of the forgotten appointment.

I found it. It was a lecture by a Fellow of a Learned Society, and it was to take place at the rather unusual hour of six o'clock. No doubt this was in order that the learned speaker might get his paper over by half-past seven, leaving his learned listeners free to dine. A taxi slowed down in front of me.

"Society of Arts," I said to the driver.

A minute later I was on my way to see Derwent Rose for the second time that afternoon.

I will tell you in a moment the subject of that lecture I had so suddenly decided to attend. First, a word as to my attitude at that time towards new discoveries and new thought in general. I was enormously, wistfully interested in them. Instinctively, at that time, I stretched out my hands to them. I had lived long enough in the world to realise that such events as Trafalgar and the French Revolution were mere events of yesterday, and the possibilities of an equally near to-morrow haunted me. I shrank from the thought that while the dead stones of the Law Courts and Australia House would still be there after I had gone, I should not at least be able to make a guess at the stream of Life, uncradled yet, that would beat and press and flow along those channels in so little a time, the new blood of London's old unchanging veins. One begins to think of these things when one is fifty.

So, at a minute or so to six, my taxi set me down in the Adelphi, when I might have been a happier man had it taken me straight to Waterloo.

And now for what that lecture was all about.

My meaning will perhaps be clearer if I give an extract from a leading article in The Times of slightly later date. On a subject of this kind I would rather use an expert's words than risk the inaccuracies that might creep into my own.

"Human beings," the article begins, "differ not only in the knowledge they have acquired, but in their dower of intelligence or natural ability. It has long been accepted that the former property may continue to increase until the natural faculties begin to abate, but that the latter has a maximum for each individual, attained early in life.... Intelligence, as opposed to knowledge, is fully developed before the age of schooling is over. Sixteen years has usually been taken as the age at which, even in those best endowed, the limit of intelligence has been reached. Obviously the standard varies in different individuals; the degree of intelligence passed through by the more fortunate at the age of ten may be the final attainment of others, and all intermediate stages occur.... Mr H. H. Goddard, an American psychologist of international repute, classifies the intelligence of his countrymen into seven grades, but believes that in exceptional cases, amounting to four and a half per cent. of the population, a superlative standard is reached at the age of nineteen. On the other hand, seventy per cent. of the citizens of the United States have to carry on their lives with the intelligence of children of fourteen, and ten per cent. with that of children of ten."

It was to hear these conclusions of Mr Goddard's expounded by a fellow-savant that I had come that afternoon to the Society of Arts.