The Treble Almanacs are three books in one: Firstly 'John Watson Stewart's Almanac' for the year, principally Irish information. Everything that there is to know about Ireland in 1818, from schools to army lists, mail and stage coaches, farming, Sunday schools, and so on. An immense amount of information in 239 pages.
Second is 'The English Court Registry', which includes all of the major people from the King, to Members of Parliament, Lords, Officers in the Navy and Army, etc. 243 pages.
And last 'Wilson's Dublin Directory', which contains a complete list of streets, lanes, alleys, etc. and a very comprehensive list of merchants and traders, extending to over 200 pages for Dublin alone.
A wealth of information and a snapshot in time.