With hindsight, we can see that so many seeds which were to blossom in historic change were planted at that time. Macmillan made the tour of Africa, the first British prime minister to visit the continent, at a crucial moment. African countries were beginning to obtain self-rule. Macmillan visited Ghana, which had become independent in 1957, and then went to Nigeria, whose independence date had already been agreed. Sudan had become independent in 1956. The question in everyone's mind was whether there could be any part of Africa ruled by whites, or was every state on the continent to have majority rule?
At home, the main news was that Prince Andrew was born and Princess Margaret announced her engagement to a photographer called Antony Armstrong-Jones. The Government decided to fund a supersonic passenger aircraft, later to be known as Concorde.
Elsewhere, there were more significant stirrings. France was threatened by a rebellion by its colonists in Algeria. In the United States, Martin Luther King had been arrested, and a young senator from Massachusetts, John F Kennedy, declared his intention to run for President. In Cuba, President Castro nationalised all private businesses.
South Africa itself was in turmoil. A 42-year-old black lawyer, Nelson Mandela, was on trial for treason, along with 155 others. At home, his young wife, Winnie, had just miscarried. He was perturbed by the militancy of the Pan-Africanist Congress, which had just split from the African National Congress.
The National Party government had been in place for 12 years. It was pressing ahead with apartheid, with a panoply of laws which constricted every aspect of life for blacks. They had just been banned from 'white' universities.
When the British Prime Minister stood up in the all-white South African Parliament in Cape Town on 3 February 1960, the dark green leather benches were lined with senators and MPs. He had not given South Africa's Prime Minister, Hendrik Verwoerd, a copy of his speech beforehand, but no one expected fireworks.
He lulled his audience into a sense of wellbeing, praising 'the great beauty of your countryside, with its farms and forests, mountains and rivers, and the clear skies and wide horizons of the veld'. But he went on: 'The most striking of all the impressions I have formed since I left London a month ago is of the strength of this African national consciousness. In different places it may take different forms. But it is happening everywhere. The wind of change is blowing through this continent.
'Whether we like it or not, this growth of national consciousness is a political fact. We must accept it as a fact. Our national policies must take account of it. . . . This means, I would judge, that we must come to terms with it. I sincerely believe that if we cannot do so, we may imperil the precarious balance between East and West on which the peace of the world depends.
'As I see it, the great issue in this second part of the 20th century is whether the uncommitted peoples of Asia and Africa will swing to the East or to the West . . . What is now on trial is much more than our military strength or our diplomatic and administrative skill. It is our way of life.'
Macmillan then sidled up to the main thrust of his speech, claiming in this shrinking world that he had a duty to talk frankly to South Africa. 'It has been our aim', he said, 'to create a society which respects the rights of individuals - a society in which men are given the opportunity to grow to their full stature, and that must in our view include the opportunity of an increasing share in political power and responsibility; a society finally in which individual merit and individual merit alone is the criteria for a man's advancement, whether political or economic.'
South Africa was stunned. Benjamin Pogrund, a young journalist covering the tour, said he remembers the normally cool voice of Dr Verwoerd shaking with rage as he tried to find words to answer Mr Macmillan. 'Mr Prime Minister, you have set me a considerable task,' he spluttered. 'We have problems enough in South Africa without your coming to add to them . . .
'We never presume to criticise the application of policies in areas for which you are responsible,' he said. 'But on an occasion like this, we can say we differ from you . . . In South Africa, justice must be done to the black man but also to the white man.'
Stung by the impertinence of an Englishman criticising the Afrikaner government on its own territory, the South African Foreign Minister, E H Louw, asked whether Mr Macmillan would dare to criticise De Gaulle over Algerian policy or talk about race in the United States.
In South Africa, the speech had little effect on the Government. Apartheid legislation went ahead. So did repression. The following month, 67 black demonstrators were shot down at Sharpeville and the ANC and PAC were banned. Shortly afterwards, Nelson Mandela proclaimed the armed struggle and went into hiding.
For the rest of Africa, Macmillan's speech did not predict a wind of change. It was already blowing. Ghana and Sudan were free and British troops were withdrawn from Egypt. Britain tried to retake the Suez canal in 1956 and failed. The United States and the Soviet Union would no longer tolerate any imperialism save their own.
There was no question of holding on to most British territories in Africa. The only question was when they would be 'ready' to govern themselves. The timetable was invariably dictated by political agitation on the ground.
But what the speech did do was set British policy unequivocally against 'white Africa'. Macmillan was saying that no part of the continent can be considered the exclusive preserve of whites.
What had led him to this conclusion? On his way to South Africa Macmillan had also visited the two Rhodesias, now Zimbabwe and Zambia, and Nyasaland, now Malawi. The colonists and Britain hoped to make these three territories into a federation, but the black population suspected it would result in a strengthening of white rule. Dr Hastings Banda, the Nyasaland leader, was in prison accused of plotting murder and treason. Visits to these countries may have strengthened Macmillan's view that resisting nationalism was impossible, but he had probably already made up his mind.
Someone who now accepts that he may have had a pennyworth of influence on Macmillan was a young man of 25 just down from Oxford, who completed a four-month trip through Africa just before Macmillan's tour. His name was Peter Brooke, currently the Secretary of State for National Heritage.
'It was an extraordinarily interesting time,' Mr Brooke said yesterday. Through his father, who was a minister in Macmillan's government, he had secured introductions to British colonial officials, while teachers at Oxford gave him contacts with many of the nationalist leaders. 'There were these two conveyor belts through Africa, and you either joined one or the other. I was able to join both. Both sides found it very useful to send messages to each other.'
When he got back, he wrote a report and gave it to his father. 'I don't know if Mr Macmillan ever actually saw it, but my father certainly discussed it with him. The Wind of Change speech was not a surprise to me, I could certainly see it coming.'
In October 1959, Macmillan had replaced Alan Lennox-Boyd as Colonial Secretary with Iain Macleod. As one commentator put it later, 'Macmillan believed in the winds of change, Macleod believed in gales of change.' The policy of cracking down on African nationalism was reversed and leaders such as Hastings Banda and Jomo Kenyatta found themselves transported from jail cells to tea with the governor. Within weeks of Macmillan's speech a constitutional conference was putting Kenya on the road to independence and the idea of a Central African Federation was dead. While Zimbabwe had to wait another 20 years for independence, and democracy in South Africa considerably longer, the Wind of Change speech committed the British Government to that path. Looking back on the speech now, it is perhaps ironic that the slow speed at which Britain travelled that path was a main factor in discouraging the new Asian and African states from establishing closer ties with the West and Britain.
And the copy of the speech sold yesterday?
Reader, I bought it.