When I visited India as a tourist 47 years ago I was told that the population of Delhi was about 3 million. I went there again late in November to do some work. The population now, so far as it can be counted, is 22 million. The contrasts, of splendour with slums, of wealth with poverty, and efficiency with unpredictable improvisation, were as apparent in 2017 as they were in 1970.