The technical description of a woodwind instrument invariably requires detailed information about the dimensions of the instrument's bore. These data are necessary for both basic organological research and that aspect of restorution which requires the reconstruction of missing parts. The article discusses the technical and statistical aspects of bore measurementsand deals with the problem of compensating for the effects of anisotropic shrinkage. A translation of a 19th century German text on the musical implications of the adjustment of bore dimensions is appended. -- AATA