As I set off down the road to town. I met many familiar faces, some Dowayo, some townsmen of Fulani or southern extraction. Politely, they enquired after the well-being of my wives and my millet crop. I did the same to them.

Inevitably, the first visit was to the chief of police, armed with all relevant documents.

Arrival in a West African town involves a European in a number of "formalities" that are neglected at his peril. They imply a curious mixture of self-importance and self-abasement. The average visitor will be amazed that the authorities should care one way or the other about his presence in their fair town. But should he fail to comply with the regulations, he is liable to be "discovered" as a spy or worse. So there is a fairly depressing circuit whereby one's presence is announced, rather as in earlier days Europeans would leave their visiting cards at strategic locations.

It had come as a great surprise to me when I visited Africa for the first time that I was unable to recognize individual Africans, being overwhelmed by superficial differences. It is rather like one's experience before a gallery of paintings of gentlemen in periwigs. Once one has got to the third, the others have disappeared from the memory. I was pleased now to be able to remember the names of people whom I had not seen for some time, until I came to one man who clearly knew me well but was a total blank in my recollection. With embarrassment, I realized that the problem was that he had changed his shirt. Most Dowayos only possess one shirt for everyday wear so, inevitably, they wear the same one all the time. Although they normally wash themselves on the way home from the fields, they almost never wash their clothes, simply wearing them to the point of disintegration and sometimes beyond. The beginner learns to recognize people by their clothes rather than their features.

Africa is hard on feet.

At the police post, there were two or three cheerful young men in baggy khaki uniforms, lounging around, having removed their boots to ease their feet. They were pointing out the various scars and wounds on their toes and heels, each one recalling a past injury or adventure.

"This is where I was bitten by a snake. All were amazed that I lived."

"Here is where I fell from my motorbike during training. The pain was very great."

A solitary prisoner was humming to himself as he painted the white stones that edged the flagpole. Above, the flag hung limply in the still air.

I was greeted by one of the recruits I knew from my last visit, an earnest Christian who was doing a correspondence course in French language. "Welcome. You have returned. What is the French word for someone who owns a grinding mill?" He chewed on a pencil and looked worried.

A corporal appeared from inside, distinctly less jovial than the loungers. His first move was to warn me that I was on government property and must take no photographs. Since I had no camera with me, this was a redundant instruction, but one accepted with due meekness. We proceeded to an inspection of my passport, with much suspicious scowling and holding up of stamps to the light. It was regrettable that the chief had departed on a mission of importance and delicacy to Garoua. Only he could take the step of allowing me to sign my name in the large book kept for aliens. How long would he be? Should I wait? This was not foreseeable but they would call the police headquarters in Garoua to verify whether he had left yet. A large radio was produced from inside the cupboard and the corporal began shouting into it amid bursts of hiss and static. A faint voice, as of a drowning man, could be heard saying something with great insistence, then in a brief pause could be heard to ask very clearly, "What do you want?" to which the corporal replied, "Who?" before the static closed in again like fog.

At that moment, a somewhat raddled Land-Rover drew up in a cloud of dust. Its green canvas top had been replaced by one of sky-blue and domestic manufacture, giving it a holiday-camp air. From this, disembarked the chief, a trifle hot and dusty but with the air of a man having come from a job well done.

"Adverse meteorological conditions," announced the corporal with finality, folding down the aerial. We both looked at the perfect blue skies over the mountains. It seemed unpolitic to say more, so I prepared to take my leave.

"I can't possibly talk to you now," he declared. "I've been to get urgent supplies. Come back tomorrow at eleven."

As I moved off, I peered in the back of the machine. As I had guessed, it was full of beer. Subsequent investigation revealed a rumour that the vehicle was used to haul beer down to the villages on the River Faro, some thirty miles away, otherwise devoid of drink. There, it was claimed, it sold for fabulous prices.

If this was so, then it was one of the police chief's more benevolent functions and he doubtless deserved the small profit so riskily gained.

In many parts of Cameroon, when the colonial forces arrived, they found a system whereby Fulani overlords ruled over pagan peoples. They found it convenient to generalize this system to parts where Fulani incursors had not reached, as at Poli. There is now a Fulani chief in the town who sits on the native court and claims jurisdiction over the area. Local Dowayos resent this very much and have as little to do with him as possible. As far as they are concerned, they were never defeated by the Fulanis. He would certainly not be welcome in their villages.

At the other end of town, the dank and depressing sous-préfet's office that I recalled had been spruced up by the application of a coat of whitewash. White-robed, clerkly figures shuffled in sandals from room to room with handfuls of papers. Admittedly their gait was hardly swift but it was the first time that anyone had been seen moving about at all in that building. The clerk who controlled admission told me that the sous-préfet was not available. Being a Dowayo, however, he revealed that he might be found if I dropped in on the town chief.

On my previous visit, he had not exactly endeared himself to me. As the proprietor of the mail truck, he had a virtual monopoly of transport between Poli and the big cities. Being very close to the old sous-préfet, he had worked hard to ensure that no bus service was permitted, no petrol sold, no one else allowed to carry passengers. Because the presence of a foreigner would attract the attention of the police to his always illegally overloaded truck, he had always made it as difficult as possible for me to travel on his vehicle, going to such lengths as changing the pick-up points or days of departure when I was out of town. A further source of friction had been his determined attempts to make me take out membership of the one political party permitted in Cameroon -- an operation on which he received a commission.

However, time having blunted our antipathy, I resolved to seek out the sous-préfet in his lair. I had the awful fear that somewhere in the hills the rite of circumcision was even now being carried out as I wasted time in town.

The sous-préfet rose and greeted me. He grinned and addressed a few words in Fulani to the town chief who scowled, drew forth the bottle and poured me a small quantity in a glass stamped "Souvenir from Cannes". We settled ourselves and the sous-préfet began to discourse in perfect French on his plans for the town. His eyes gleamed enthusiastically behind his glasses as he told of piped water and the re-installation of mains electricity (a convenience that had been allowed to lapse since the departure of the French). He was determined to have a telephone before two years had passed. "My job is to animate," he explained. "I have already explained to my friend here", he indicated the chief, "that his house may have to be demolished for my telephone exchange." He giggled wickedly to which the chief returned a wan half-smile.

After much hand-clapping outside the chief's house, a small boy appeared and scuttled off to announce my arrival. In due course, I was shown into a small round hut with a floor of gravel. The walls were painted with geometric Fulani motifs and the overall effect was of a clean and pleasant dwelling.

Stretched out on rugs on the floor were the chief and the sous-préfet. They were listening to Arab music on the radio. As I entered, the chief tucked a bottle of whisky deftly into his robes. It looked like a movement refined by many years' practice.

The ethics of anthropology are not easy. The anthropologist normally attempts to influence the people he is studying as little as possible but knows that he must have some effect. At the best, he may restore to a demoralized, marginal people something of a sense of their own worth and the value of their own culture. But, by the very act of writing the standard monograph on any people, he presents them with an image of themselves that must be coloured by his own prejudices and preconceptions since there is no objective reality about an alien people. The use they make of this image is unpredictable. They may reject it and react against it. They may also change to conform more closely to it and become ossified actors portraying themselves. Either way, innocence, the sense that something is done because this is the only way things can be, is lost.

"I am determined to make the Dowayos active. You will please supply relevant information."

During the colonial era, anthropologists always had a very uneasy relationship with the authorities, who wanted to use them to change people. Now, it seemed, it was happening to me. "Why are the Dowayos so lazy?" he asked.

He waved at me a copy of a book by Mrs Gandhi. "I have been reading this book by the daughter of Gandhi. She says many good things about the evils of colonialism."

I told him that Mrs Gandhi was not Gandhi's true daughter. He looked shocked. "But how is this possible? This is dishonest. Are you sure?"

"Why are you so energetic?" I retorted. He laughed.

Thereafter, he questioned me on almost every occasion we met whether or not Mrs Gandhi was indeed the true daughter of Gandhi. I began to wonder myself, my former certainty sapped by his anxious inquiries. It seemed that the matter was crucial to the value of her book. When I returned to England and was met by friends at the airport, they must have thought it odd that the first thing I asked them was: "You know Mrs Gandhi? Well, is she the true daughter…?"

I mentioned to the sous-préfet that I had just been to see the police chief and wondered whether he knew of the surreptitious beer business in which he was engaged. He giggled. "There was a time when he made you sweat a little."

He was referring to a time when I had got lost in the bush at night and, heading for the nearest light, had ended up behind the house of his assistant. The police chief had immediately been firmly convinced that I was spying and given me an anxious moment or two as he interrogated me.

I thanked him profusely and withdrew, liking him even more than before, glad that he had confounded all those who had been convinced that the dogged stubbornness of Poli and its inhabitants would swiftly break his optimism. The town chief had not said a word and only grudgingly shook hands when I left.

"He is a good man," said the sous-préfet, "perhaps a little overzealous at times." He grinned, leaning forward, and prodded me with the collected wisdom of Mrs Gandhi. "I kept my eye on him, you know. I wouldn't have let anything happen to you."

In the street, the first rains had begun to fall, big wet drops running along the surface of the dirt as if over hot iron. I trudged on in the thick dry-season dust, the street suddenly full of little boys who screamed and swooped with joy, holding out their robes for the sheer pleasure of being wet and cool.

By the time I had reached the bridge to the mission, the river had become a raging torrent and there was no possibility of crossing. Such was the force of the water that your legs would simply have been washed out from under you. Besides, I was not eager to plunge my pristine feet, laboriously debugged in England ("See, this is where I had riverworm. Here they removed jiggers."), into this, the first flood of the year. Notoriously, this was the spate that washed downstream a whole year's accumulated filth and pollution.

When I finally arrived at the mission, darkness was falling. The only dry clothes I could find were long Fulani robes that Jon and Jeannie had bought as a souvenir. Marcel and Ruben went into hysterics as soon as they saw me and mercilessly followed me around calling out, "Lamido, lamido' ("Chief, chief").