I just can't resist things like this, which were central to the lives and work of the people who once owned them, this one seeming a bible of sorts for a George F. Ingham, who I presume was a machinist of some kind. Plus I just find the blue of these blueprints so gorgeous, and all the better for all of the very precise columns and grids of measurements and calculations packed onto them. Covering a spectrum of types of rivets, wire, screws, bolts, gears, pipes, etc etc, including dimensions and strengths, plus charts of common logarithms, trigonometric functions, etc.--perhaps good for showing to the student who finds math pointless! With a leather cover and brass clips holding it all together, and handwritten notes on the backs of some of the pages. 

 6 1/4" x 3 3/4" x 3/4". About 40 blueprint pages. All in very good condition. Great patina to the leather, with a burn to the reverse side bottom corner, it seems surely incurred on the job!