This is just additional information in conjunction with BrutalSleeper's solution, which does a great job of describing the location. This is just to make sure you don't miss it by advancing the level with the dumbwaiter ride.
You want to be sure to find the Constitution BEFORE you go up the dumbwaiter... Not sure if it's too late at that point, but you should find it (as described in BrutalSleeper's solution) after that first elevator ride up... Just go straight (and then right) as you leave the first room, not left... It seems you have plenty of time to find it, as I went left, cleared the floor and still came back for it.
Thank you to Stoiss for the following: "It should also be noted that the paper is on a book to the right of the furnace."