Oval Domes: History, Geometry and Mechanics

An oval dome may be defined as a dome whose plan or profile (or both) has an oval form. The word Aoval@ comes from the latin Aovum@, egg. Then, an oval dome has an egg-shaped geometry. The first buildings with oval plans were built without a predetermined form, just trying to close an space in the most economical form. Eventually, the geometry was defined by using arcs of circle with common tangents in the points of change of curvature. Later the oval acquired a more regular form with two axis of symmetry. Therefore, an “oval” may be defined as an egg-shaped form, doubly symmetric, constructed with arcs of circle; an oval needs a minimum of four centres, but it is possible also to build polycentric ovals. The above definition corresponds with the origin and the use of oval forms in building and may be applied without problem until, say, the XVIIIth century. Since then, the teaching of conics in the elementary courses of geometry made the cultivated people to define the oval as an approximation to the ellipse, an “imperfect ellipse”: an oval was, then, a curve formed with arcs of circles which tries to approximate to the ellipse of the same axes. As we shall see, the ellipse has very rarely been used in building. Finally, in modern geometrical textbooks an oval is defined as a smooth closed convex curve, a more general definition which embraces the two previous, but which is of no particular use in the study of the employment of oval forms in building. The present paper contains the following parts: 1) an outline the origin and application of the oval in historical architecture; 2) a discussion of the spatial geometry of oval domes, i. e., the different methods employed to trace them; 3) a brief exposition of the mechanics of oval arches and domes; and 4) a final discussion of the role of Geometry in oval arch and dome design

Khâ-m-uas et le régime sénorial

Daressy Georges. Khâ-m-uas et le régime sénorial. In: Bulletin de l'institut égyptien, tome 1, 1900. pp. 5-6

Deuxième note sur la prétendue maison de saint Louis à Mansourah

Daressy Georges. Deuxième note sur la prétendue maison de saint Louis à Mansourah . In: Bulletin de l'Institut d'Egypte, tome 1, 1918. pp. 135-149

Séance spéciale du 31 mars 1921

Daressy Georges. Séance spéciale du 31 mars 1921. In: Bulletin de l'Institut d'Egypte, tome 3, 1920. pp. 105-106

Quel est l’âge du Sphinx ?

Daressy Georges. Quel est l’âge du Sphinx ?. In: Bulletin de l'institut égyptien, tome 7, 1906. pp. 93-97

Séance du 19 avril 1920

Daressy Georges. Séance du 19 avril 1920. In: Bulletin de l'Institut d'Egypte, tome 2, 1919. pp. 132-133

Moustapha pacha, le prisonnier d’Aboukir

Daressy Georges. Moustapha pacha, le prisonnier d’Aboukir . In: Bulletin de l'Institut d'Egypte, tome 11, 1928. pp. 43-70

Séance du 4 novembre 1918

Daressy Georges. Séance du 4 novembre 1918. In: Bulletin de l'Institut d'Egypte, tome 1, 1918. pp. 181-183

L’antiquité des statues de Chefren

Daressy Georges. L’antiquité des statues de Chefren. In: Bulletin de l'institut égyptien, tome 1, 1900. pp. 6-9