The A070 Tendency Barometer is mounted on a sandblasted solid glass frame. The crisp modern look is accented by the colorful measuring tubes.
The Tendency Barometer was patented on December 23, 1818 by Alexander Adie. It consists of two liquid filled, mercury free tubes. One tube in a U-shaped which is open ended and filled with a red fluid; and one closed thermometer tube filled with a blue fluid, mounted parallel to each other.
When the fluid levels are the same, the weather is changing.
When the red fluid level is below the blue fluid level, the weather is fair (high pressure pushes the red fluid down in the tube).
When the red fluid level is above the blue, stormy weather is predicted (low pressure allows the red fluid to move up the tube).
The thermometer measures in both Celsius and Fahrenheit and the barometer measures in inches and millibars/hPa. The overall instrument measures 18 inches high by 4.7 inches wide and weighs 2 pounds.
USA Orders Only (no international, APO and FPO orders, please).
This item can only ship GROUND SHIPPING. Do not choose Air shipping.
Generally leaves the warehouse in 1-2 business days.