Unidentified photographer / artist
1835, 22 August
Camera Lucida

Magazine page
Google Books
Published in "The Dublin Penny Journal", Vol. IV, No.164, August 22, 1835, p.61
 
Q. How does the camera lucida act in the formation of pictures ?
 
A. The camera lucida, one of the most elegant of optical instruments, consists of the following arrangement ò CDFG is a glass prism, having four sides inclined, as seen in the figure. The side CD being exposed to the object to be delineated, rays pass through it and fall upon the sloping side DF; from this they are reflected to the side FG, and finally pass out of the prism to the eye at E. Now, from the direction in which rays enter the eye, it receives them as if coming from an image at A'B'. Accordingly, if a sheet of paper be placed below the instrument, a perfect delineation of the object will be formed upon it, which may be easily traced off with a pencil.
 
The instrument is mounted on a convenient brass frame, which is so constructed as to allow the prism to approach to, or remove from, the paper, according to the size which the picture is required to have.
 
LL/34608