Marie Antoinette's

...there is to be some sort of a Masquerade, but as it differs very much from anything you understand by a Masquerade, it will be necessary I shou'd explain it.

Everybody was allw'd to come in that paid the price, which, as it was very low, the Company was of all sorts, but not in the Boxes; they all belong to the people of fashion.

Everybody was allowed  (like the Masquerades at Florence) to be in their usual dresses or in Mask, so the Company was composed of Masks & no Masks, but the principal part of the Masquerade consisted of twenty Gentlemen who came in at first all as Shades, & concealed in their shadow dresses the Materials for erecting a Temple, which rose in a few minutes opposite to the Box of the Princess de Carignan & in large letters were wrote 'A la Beaute.'

The Shades then became ancient dresses of the different Nations & very fine ones. They all proceeded to the box of the Princess of Carignan, who was a very fine mask, & all the Ladies who were with her were in different dresses: they were all presented with large noesgays of Artificial flowers, after which they returned where they had erected their Temple, which disappear'd as quick as it rose.

I love the image presented of the twenty men, who clearly preplanned the event knowing the Princess de Carignan was going to be in attendance.  They planned to arrive as Shades in long robe like costumes, so that they could easily hide the fabric and items needed to create a 'temple' which I imagine included sheets with the words le beaute on them. All directed at the pretty lady, imagine if it were you!