|Curtis's Acoustic Chair|
While researching another topic entirely, I came upon Mr. Curtis’s Acoustic Chair. This is another of the items that were familiar enough to people at the time to become the subject of witticisms, while being completely new to me.
“Mr. Curtis, about 1830, by the aid of several mechanics, brought out his acoustic chair, which was stated to possess such wondrous power, that His Majesty could sit in his palace, at Windsor, and hear communications from his ministers at Whitehall. Whether our present Sovereign does not require her ministers to keep at such a distance, and, therefore, has not patronized Mr. Curtis's acoustic chair, or whatever other cause may have operated, probably will never be known, but that gentleman's name does not appear to be continued in the list of Her Majesty's household.”— William Wright, A Few Minutes' Advice to Deaf Persons (1839)
Mr. William Mullinger Higgins’s Philosophy of Sound and Musical Composition (1838), whose relevant pages I show above, contains the shortest and easiest-to-understand explanation I came upon.
You can learn more of the technical details in the Mechanics’ Magazine of January 14, 1837 here.
Another illustration (of the chair at home) and explanation appeared in The Mirror of Literature, Amusement, and Instruction on 18 February 1837 here.
Clicking on the image will enlarge it. Clicking on the caption will take you to the source, where you can learn more and enlarge images as needed.