the developing process. In 1881, he published his discovery. Berkeley's formula contained pyrogallol, sulfite, and citric acid. Ammonia was added just before use to make the formula alkaline. The new formula was sold by the Platinotype Company in London as Sulphur-Pyrogallol Developer. Nineteenth-century experimentation with photographic processes frequently became proprietary. The German-born, New Orleans photographer Theodore Lilienthal successfully sought legal redress in an 1881 infringement case involving his "Lambert Process" in the Eastern District of Louisiana. Popularization The daguerreotype proved popular in response to the demand for portraiture that emerged from the middle classes during the Industrial Revolution. This demand, which could not be met in volume and in cost by oil painting, added to the push for the development of photography. Roger Fenton and Philip Henry Delamotte helped popularize the new way of recording events, the first by his Crimean War pictures, the second by his record of the disassembly and reconstruction of The Crystal Palace in London. Other mid-nineteenth-century photographers established the medium as a more precise means than engraving or lithography of making a record of landscapes and architecture: for example, Robert Macpherson's broad range of photographs of Rome, the interior of the Vatican, and the surrounding countryside became a sophisticated tourist's visual record of his own travels. In 1839, François Arago reported the invention of photography to stunned listeners by displaying the first photo taken in Egypt; that of Ras El Tin Palace. In America, by 1851 a broadsheet by daguerreotypist Augustus Washington was advertising prices ranging from 50 cents to $10. However, daguerreotypes were fragile and difficult to copy. Photographers encouraged chemists to refine the process of making many copies cheaply, which eventually led them back to Talbot's process. Ultimately, the photographic process came about from a series of refinements and improvements in the first 20 years. In 1884 George Eastman, of Rochester, New York, developed dry gel on paper, or film, to replace the photographic plate so that a photographer no longer needed to carry boxes of plates and toxic chemicals around. In July 1888 Eastman's Kodak camera went on the market with the slogan "You press the button, we do the rest". Now anyone could take a photograph and leave the complex parts of the process to others, and photography became available for the mass-market in 1901 with the introduction of the Kodak Brownie. Stereoscopic photography Charles Wheatstone developed his mirror stereoscope around