4" x 3" refrigerator magnet features an 1855 black and white advertising broadside for Root's Daguerreotype Photography Studio in Washington, D.C. The original ad is in the Library of Congress collection

Root was located at 290 Pennsylvania Avenue, at the NW corner of 11th street, above Sylvester's Drug Store. They produced daguerreotypes, talbotypes, stereoscopics, crayon, portraits and miniatures.

I found a reference on the web indicating that the proprietor was Marcus A. Root, although his primary studio was in Philadelphia. Another reference said he acquired another photographer's studio, in New York, so perhaps this D.C. shop was another acquisition. Marcus had a younger brother who was also a photographer, Samuel, but I haven't found anything to suggest that he had a studio in Washington. The ad flier was printed in Philadelphia by Chandler Printing House.

Daguerreotypes were the first practical photos. The process was developed by Louis Jacques Mande Daguerre in 1939. They were popular from around 1840 to 1860. A daguerreotype was a plate of silver-coated copper that was exposed to daylight while still in the camera, for as long as 20 minutes. It was then developed with mercury vapor and immersed in sodium chloride. Without a negative, there was no way to make duplicates. The result was fragile and glass framing was customary for protection. Crayon Daguerreotypes were vignette daguerreotypes in which the outer edges of the image were blurred by using wire shapes during the exposure process. The process was patented by J. A. Whipple (1822–1891) and promoted by Marcus Root. Stereoscopics were made by using a stereoscopic camera to take the picture. The camera produced two views, one for each eye. When viewed with a stereoscopic viewer, the two images are joined and the image simulates the dimensional depth seen by the eyes. Talbotypes were paper prints made by a process invented by William Henry Fox Talbot in 1841, originally patented as the calotype. Using a negative, silver nitrate coated writing paper was exposed to sunlight. Talbotypes were short lived, probably because they were prone to fading.