Lord Rosse invited me to peruse the Castle's archives of correspondence to the Earls from astronomers of the 19th century.  I was especially interested in letters to the Fourth Earl from J. L. E. Dreyer (who worked for a few years as an observing assistant at the Leviathan) and E. S. Holden (who would become the first Director of the University of California's Lick Observatory.)  Since flash photography is forbidden, I placed letters of interest on this table to take maximum advantage of ambient sunlight.