Source: Mary Mayo Crenshaw (ed.), An American Lady in Paris, 1828-1829: The Diary of Mrs. John Mayo (Boston, Houghton Mifflin company, 1927), pp. 50-51
Text: One fine morning we went to see the Diorama. This novel exhibition is intended to show correct delineations of nature and art, and differs from a panorama in that, instead of a circular view of the objects represented, you have the whole picture at once in perspective. The interior of the building resembles a small theatre and such is the effect of the various modifications of light and shade that the optical deception is complete. Four different pieces are at present exhibited: The passage of the Alps by Mount Saint Gothard. Nothing can be more picturesque and romantic, it is the most perfect representation of nature that can be conceived. You behold in the distance a part of Saint Gothard, covered with eternal snows, the blue summit of Val Briditto on the left and on the right a part of Monte Piottino. The length seems immeasurable, and now and then an eagle is seen wheeling round and round until it is lost in the clouds, which is done by some sort of machinery which we cannot discover. There is water really falling down the cataract, and you hear the noise of it and see the mist rising from it. I am convinced the reality can be no more stupendous than this representation. The next piece is a view of the interior of a cathedral at Rome, the third is a part of the ruins of the Coliseum, which Mr. Mahan (one of the gentlemen who went with us) said was perfect. He had recently returned from Italy, where he had seen it, and he was struck with the truth of the execution. The fourth and last was a beautiful exhibition of the Place of Saint Mark in the city of Venice. They were all extremely fine, but nothing in my opinion could be compared to the scene in the Alps.
Comments: Mrs. John Mayo, born Abigail De Hart (1761-1843) was the daughter of promiment US lawyer John De Hart and was married to Virginia planter John Mayo. Although her publication is given to be a ‘diary’ there are no dates and really a travel book. The diorama was a visual spectacle presented in an elaborate theatre, able to accommodate around 350 people. The audience would viewed a large-scale landscape painting on a screen 70ftx45ft whose appearance would alter through the manipulation of lighting and scenic effects. A turnable would then rotate the audience around to view a second painting. The Diorama premiered in Paris in 1822 and remained on show to 1828.
Links: Copy at Hathi Trust