The "Langer Encyclopedia," as the professional academics call The Encyclopedia of World History originally edited by the late William L. Langer, is basically a history of everything--and an outstanding reference volume. Want to know why the English called their 10th-century king Ethelred "the Unready"? See page 181. Or what the Ottoman Empire's constitution of 1876 said? See page 531. Or when women in Honduras got the vote? See page 955.

This book covers everything from aegis cruisers to M1A1 tanks. It is a good book. It doesn't go into detail about weapons but it does mention a weapon's stregths weaknesses and performance specs.