A pair of slide rules – one in wood, one in plastic – used to compare the power of various explosives, tested on a device called a ballistic pendulum.
From Nobel’s Explosives, Ayrshire.
Explosive Testing Slide Rules
A pair of slide rules – one in wood, one in plastic – used to compare the power of various explosives, tested on a device called a ballistic pendulum.
From Nobel’s Explosives, Ayrshire.