The reported pressures are converted to modern piezo transducer numbers using Burrard’s formula if originally expressed as Tons/sq. inch by LUP (Lead [Crusher] Units Pressure), or by adding 10-14% if expressed as PSI by LUP

Reported pressures varied significantly depending on pre-WWI British, between the wars U.S. (mostly Coxe's data), and post-WWII frown