Lithography was invented by Alois Senefelder in the Kingdom of Bavaria, now part of Germany, in 1796. It is called a planographic medium, because it uses limestone blocks or metal plates that are left completely flat and not carved (as is done in etchings or wood cuts). For many years artists made few lithographs due to technical difficulties with the media. In the 19th century, printer Godefroy Engelmann successfully resolved those difficulties, allowing artists to implement the use of lithography. When making a lithograph, the artist draws an image directly onto the stone or plate with a greasy material such as a crayon. After additional steps to prepare the surface, a solution of gum Arabic in water is applied to the stone, the gum sticks only to the non-oily surface. Water is sponged over the stone where it adheres to the gum Arabic coated areas and is repelled by the greasy image. Next an oily ink is spread over the surface which adheres only to the image. Finally, a sheet of paper is placed on the surface and both are run through a press which applies even pressure over the surface, transferring the ink off the image onto the paper. James Whistler described his lithographs as "Songs on Stone." He created 179 lithographs, many of atmospheric subjects that were not entirely successful with his audience of the time. His print, plus the print by Honoré Daumier in the LIMNING LITHOS exhibition were created in the early years of artistic lithography of the 1800s. The remaining thirteen artists in the exhibition were mid-20th century lithographers. Among those exhibited are Social Realist artists, Joseph Hirsch, Raphael Soyer, and Marion Greenwood; maritime artists, Gordon Grant and Stow Wengenroth; and Lili Réthi who specialized in architectural images. LIMNING LITHOS may be seen in the Gladys Lux Historical Gallery on the second floor of the LUX Center for the Arts from January 4, 2018 to May 2, 2018. The exhibition is curated by Susan Soriente, Print and Historical Collections Curator, LUX Center for the Arts.