Slide rule for e.g. fuel consumption calculation - has logarithmic scales representing fuel tank capacity distance travelled and average consumption

摘要

The slide rule consists of a body (1) in which a sliding scale plate (2) is inserted. On one of its edges, the body has a logarithmic scale (3) which faces another logarithmic scale (4) running in the same direction and drawn on the sliding plate. A moving pointer (5) on the sliding plate corresponds to a further logarithmic scale (6) which is drawn on the opposite edge of the slide rule body and runs in the same direction as the other scales. If the slide rule is used to calculate the fuel consumption of a vehicle, scale (3) represents the capacity of a full tank of fuel, and scale (4) is set to the distance covered. Scale (6) then indicates the rate of fuel consumption.