When I was home in Britain on holiday last summer, I spent an evening looking at photos my father had taken when he stayed with us in Beijing in the spring of 1966. Of all these interesting scenes of the past, the one I exclaimed at was a photo of Chang An Jie at Tiananmen. The photo showed one car and two bicycles! This made me reflect on the changes that have transformed Beijing since I came to the city 37 years ago. In those days, the bicycle was king. What sheer joy it was to cycle along with the hundreds (not thousands) of fellow pedallers (骑车人), never in fear of life and limb as one is now. I bought my first bike in 1963. It cost me 150 yuan-in those days three or four months' salary for the average city dweller. Such changes! Good or bad? Today, cycling is hazardous but bikes are easily affordable. Gone are the old wooden houses I remember in south Beijing and fast disappearing are the small, overcrowded courtyard houses lacking running water, central heating and bathroom. Very many Beijingers now live in more convenient, better-equipped flats in high-rises. But these very high-rises are swallowing up the unique character of the old city of narrow hutongs, age-old siheyuan and close-knit communities. I loved years ago to cycle to Beihai to visit my friends (I then taught at China Foreign Affairs University). In spring I rode through the blue-green wheat fields, in summer through fields of tall maize (玉米). Further west beyond Beijing Foreign Studies University there were the vegetable fields of the Evergreen Commune (四季青公社) and the rice paddies glistening in the summer sun. But now, as Beijing stretches out further and further, west, east, north, south, there's decent housing for families, busy offices for employment and large department stores and supermarkets where, if you have the money, there's little you cannot buy. What is the principal purpose for the author to write this article?