Pocket Ref by Thomas J. Glover
Want to know the melting temperature of a metal? Here it is, you can look it up in Pocket Ref. Sure you could find the information on line, but it’s faster to use Pocket Ref, and you know it’s accurate.
It’s got minerals and their hardness, spec.s on nuts and bolts. Someday, you’ll have an urgent need for this kind of information, and Pocket Ref will save the day. An excellent gift for the tool-nut in your family.