BRL Nuclear Weapon Effects Computer (ca. 1960)
The Nuclear Weapons Effects Computer No. 1 was manufactured by Blundell Rules Limited of Weymouth England. Since the company moved to Weymouth in 1956 and changed their name in 1964, it probably dates from 1960 plus or minus a few years. A slightly different (later?) version was marketed as Computer No. 2
Its purpose is to predict a variety of consequences of a nuclear explosion. The magnitude of the burst is specified (in kilotons or megatons) and the calculator estimates, for various distances from ground zero, the damage to buildings, the crater dimensions, the percent of the population killed, trapped, and seriously injured. The back of the slide rule has a table that estimates the extent of the main fire zones.
Size: 5" diameter