^{1} In this article the following abbreviations will be used Callebat—Callebat, Louis, Vitruve De L' Architecture Livre VIII (Budé, ed.; Paris, 1973)Google Scholar.

GdM—de Montauzan, Germain, Les Aqueducs Antiques de Lyon (Paris, 1908)Google Scholar.

Smith—Smith, Norman A. F., ‘Attitudes to Roman Engineering and the Question of the Inverted Siphon’, *History of Technology*, 1976, pp. 45–71Google Scholar.

MAGR—Grenier, Albert, Manuel de l'Archéologie Gallo-Romaine (Paris, 1960), 4, 1Google Scholar.

Plommer—Plommer, W. H., Vitruvius and Later Roman Building Manuals (Cambridge, 1973)Google Scholar.

SAT—Forbes, R. J., Studies in Ancient Technology (Leiden, 1964), 1Google Scholar.

Ward-Perkins—Ward-Perkins, J. B., ‘The Aqueduct of Aspendos’, *PBSR*, 1955, 115–23Google Scholar.

Other abbreviations are as in *L'Année Philologique*.

The following will not be abbreviated but will be referred to, and may be found of value for reference

Ashby, T., The Aqueducts of Rome (Oxford, 1935)Google Scholar.

Babbitt, and Doland, , Water Supply Engineering (New York, 1955)Google Scholar.

Belgrand, M., Les Aqueducs Remains (Paris, 1875)Google Scholar.

Blanchet, A., Recherches sur les Aqueducs et les Cloaques de la Gaule Romaine (Paris, 1908)Google Scholar.

Casado, C. F., Aqueductos Romanes en España (Madrid, 1972). (see n. 50, *infra*)Google Scholar.

Grimal, P., Frontin: les Aqueducs (Budé, ed.; Paris, 1961)Google Scholar.

Grimal, P., ‘Vitruve et la Technique des Aqueducs’, *R.Phil.*, 1945; 162–74Google Scholar.

Kretzschmer, F., ‘La Robinetterie Romaine’, *RAE*, 1960, 89–113Google Scholar.

Mortet, V., ‘Recherches Critiques sur Vitruve et son Œuvre; IV, Vitruve et l'Hydraulique romaine’, *RA*, 1907, 75–83Google Scholar.

Stehlin, K., ‘Über die Colliviaria oder Colliquiaria der Römischen Wasserleitungen’, *Anzeiger für schweizerische Altertumskunde*, 1918, 167–75Google Scholar.

Van Buren, A. W., *RE* VIII A, *s.v. Wasserleitungen*, 472–5 (1955)Google Scholar.

Van Deman, E., The Building of the Roman Aqueducts (repr. Washington, 1973)Google Scholar.

For a commentary on current studies on aqueducts and a general bibliography of the field the reader may find of interest a study at present in the press: Hodge, A. Trevor, ‘A Plain Man's Guide to Roman Plumbing’, EMC XXVII, N. S. 2, 3 (1983)Google Scholar. (This journal is also known as *Classical Views*, University of Calgary.)

Special mention must be made of the first three authors listed, Callebat, de Montauzan and Smith, for together they form the indispensable basis of any study of siphons. Each is marked by a wide interest and knowledge of the subject as a whole, but does have a specialised approach—Callebat is primarily interpreting a literary text, de Montauzan giving an account of the archaeological remains, while Smith is a historian of hydraulic engineering and an authority on the technical aspects. It will thus be seen that, taken together, they form a particularly powerful combination. I need scarcely mention my own debt to these three sources, for even a quick glance at my footnotes and references will make it plainer how much I owe to them than could any formal acknowledgement here. I must, however, express my gratitude and indebtedness to Prof. D. R. Townsend, of the Faculty of Engineering, University of Ottawa, a specialist in hydraulics, and to Eng. Herenguel, of the Société du Canal de Provence, for much valuable assistance on technical matters: they are in no way responsible for any mistakes in this account, which remain entirely my own contribution.