In Photography and Invisibility, Douglas Nickel identifies two different photographic techniques that corresponded to two different ways of seeing and recording the world in the 19th century. Explain these two different approaches to vision and their influence on artists by making explicit reference to Nickels essay and to the following images: Peter Henry Emersons At Plough, the End of the Furrow, 1887, photogravure and Eadward Mubridge, Horse Galloping, 1887, collotype.MLA formating, cover page, reference page, 4 pages