Since London was considerably bigger than New York and Berlin during this period, it is hardly surprising that more sources are available on London than on the other two cities. But London also has the edge in terms of quality. In particular, there are the incomparable riches of Charles Booth's Life and Labour of the People in London, 17 vols. ( London, 1902-3), and of the Booth Collection at the London School of Economics, which contains the notebooks on which the work was based. Other outstanding sources for London include Richard Mudie-Smith, ed., The Religious Life of London ( London, 1904), with its comprehensive data on church and synagogue attendance; the collections of visitation returns for the London, and for the Rochester and Southwark dioceses, which are respectively at Lambeth Palace Library and at the Greater London Record Office; and the tapes and transcripts of interviews conducted by various oral historians. These latter have been my most important London source. In particular, Paul Thompson and Thea Vigne's project on Family and Work Experience before 1918, tapes and transcripts from which which are held at the Department of Sociology, Essex University, are of immense value to anyone researching the social history of Britain in the early twentieth century. Though religion was not one of the principal themes of the project, information was systematically collected on such subjects as churchgoing and Sunday schools, and much information about religion and irreligion emerges incidentally. I have discussed this material and some of the problems in its interpretation in Hugh McLeod, "'New perspectives on Victorian working‐ class religion: The oral evidence'", Oral History, 14 ( 1986), pp. 31-49.
There are three areas in which Berlin has the advantage over the other two cities so far as sources for a study of this kind are concerned. First, it has in the Evangelisches Zentralarchiv an outstanding church archive, with material compiled by the Prussian church authorities on many aspects of church life. Second, the fact that the state took a closer interest in the religion of its citizens in Prussia than in England or the United States meant that a wider range of statistical information about religious affiliation and practice is available for Berlin, and that some types of records exist that have no parallel in the other cities. The Statistisches Jahrbuch der Stadt Berlin, published annually, included an extensive section on religion, so that long runs of statistics are available for Berlin when often only more fragmentary data are available for London or New York. Information is also available about those changing denomination, or leaving the church altogether, as they were required to complete forms, some of which have been retained in parish archives. And third, numerous histories of Berlin parishes are available, and they tend to be of higher quality than their counterparts in London and New York. Two other kinds of source, which are also available for London and New York, but seem to me to be of exceptional quality in Berlin, are city mission journals (I found Blätter aus der Stadtmission invaluable), and writings by clergymen, describing their work or commenting on aspects of religion in the city—horbar;here I found books by two pastors of north Berlin parishes, the conservative Eugen Baumann and the radical Günther Dehn, very helpful.
In New York I was able to find much more evidence than in the other cities on the social composition of religious denominations and of specific congregations. There were two reasons for this: first, the invaluable surveys conducted in the years around 1900 by the Federation of Churches and Christian Workers in New York City published in Sociological Canvass, 3 vols. ( New York: 1897- 1901)