Abat-jour, a name given by architects to a sort of window or opening designed to let light into any subterranean floor used for kitchens, pantries, cellars, etc. These are commonly called soupiraux. [1] They get light from above by beveling the supporting wall, which can be either in talus or glacis, with more or less of an incline as the thickness of the wall permits. They are usually wider than they are tall. Since their exterior forms have no relation to the overall proportions of the building, they are the only sort of window where proportion is a matter of indifference, though some architects have affected in the Attic order [2] to insist upon making windows longer on one side than the other, in imitation of the abat-jours; this can be seen in case of the Tuileries Palace [3] on the façade facing the great courtyard. [4] Doing this should be avoided, however, for it was unreasonable to use there a form of window in the upper stories that was, as it were, meant for soupiraux .

We also call abat-jour windows the great stained-glass window of a church, or the large multi-paned window of a grand salon or gallery, [5] when a sloping surface has had to be made for the window at the upper or lower cross-bar of its embrasure, to compensate for the inequality of height that can occur with the interior or exterior décor of an edifice; as we see in the Invalides, [6] in the vestibule, and in the gallery of the château of Clagny. [7]

1. The singular form is soupirail.

2. L’ordre attique refers to the neoclassical style of using of short pilasters beneath a cornice with architrave, as in the palace of Versailles.

3. The Tuileries Palace was built in the 16th and 17th century at the end of the great axis of which the Champs-Élysées is the best-known part. It was the royal residence in Paris of many French monarchs from Henri IV through Napoléon III, and thus of Louis XV during the preparation of the Encyclopédie, but was burned down in May 1871 by supporters of the Commune and entirely demolished in 1883.

4. The arc du triomphe du Carrousel, which still stands, was approximately in the center of the vast courtyard referred to here.

5. Blondel uses for both windows the term vitrail (plural vitraux), usually translated as ‘stained-glass window,’ but not all vitraux employ stained glass. Stained glass was not used in the window in the gallery of the château of Clagny referred to at the end of the article.

6. Blondel is presumably referring to the Église Saint-Louis des Invalides and the adjacent royal chapel with its famous dome, beneath which since 1861 the remains of Napoléon repose in an enormous sarcophagus. As one of the most important expressions of French classicism, this is one of the most celebrated monuments in Paris, begun by Hardouin-Mansart and Bruant in the late 1670s and finished only in 1706.

7. The Château de Clagny, especially famous for the gallery mentioned here, was built in the 1670s by Jules Hardouin-Mansart (with gardens by Le Nôtre) for Madame de Montespan, Louis XIV’s most famous maîtresse en titre. It stood near the Château de Versailles. The Château de Clagny was demolished in 1769.