How has a Christian church been aligned towards the East? Conclusions from statistical analyses of churches built between 300 and 1300

摘要

Historically nearly nothing has been handed down about the techniques for how a Christian church was built to a certain axis angle. The main aim of the study was to investigate whether church axis angles have been aligned in a west-east direction by either 'astronomical' or 'equinoctial date' orientation. Axis angles of 3014 churches were measured using Internet satellite maps. Multiple regression analyses provided statistical evidence for both astronomical and equinoctial date orientation, whereby probable technical aids (e.g., gnomon, astrolabe) came into use and not direct observations of the sunrise. The left-skewed distribution of church axis angles can be related statistically to an 'Easter window' orientation. However, the statistical analyses also allow for the conclusion that most of the angle orientations of the church axes were rather 'roughly estimated'. No axis angle could be significantly assigned to sunrise angles on a saint's day; however, larger samples are necessary to finally reject this hypothesis. When churches are located on or in Roman masonries, their axis angles often coincide with the orientation angles of the Roman walls, indicating a pragmatically adopted alignment. Taken together, in most cases attempts were made to align churches towards the sunrise at the equinoxes, as requested by the ecclesiastical authorities.