Barometers Realm

Predictive scales were popular among a wide range of people: from enthusiasts who observed the weather as a hobby to farmers and sailors. One company that achieved significant success in producing such devices was the British firm Negretti & Zambra. Founded in 1850 by Henry Negretti and Joseph Zambra, the company specialized in the production of scientific and optical instruments. They became widely known for their high-quality barometers, thermometers, and astronomical and meteorological devices. Negretti & Zambra produced instruments for Her Majesty Queen Victoria, Prince Albert, and King Edward VII. Their products were sought after in both scientific circles and among everyday consumers, thanks to the precision and reliability of their instruments.

In 1938, after Ernest Heath conducted 5,295 observations, it was determined that the accuracy of the forecasts had reached 90%. This meant that out of all the observations, only 15 forecasts were incorrect, and 495 were partially correct. These accomplishments solidified the company’s reputation as a manufacturer of reliable and accurate meteorological instruments.

One of the company’s innovations was the production of mechanical weather predictors, more complex devices with an internal system for inputting and analyzing data. These instruments could be placed on a desk or windowsill, alongside a barometer, to provide forecasts for the next 12 hours. For instance, the "tabletop synoptic," released by Negretti & Zambra, became popular. It allowed users to input data on pressure and wind direction to receive a weather forecast. The mechanical device, just 14 centimeters tall, was made of wood, giving it a warmth and tactile appeal. On the front of the case was a brass plate with carefully engraved scales. Two manually adjustable metal disks allowed users to enter data about the current wind direction and atmospheric pressure, recreating the original method of operation.

To get the forecast, the user would turn a brass knob on the case, which set the mechanism in motion, and the result would appear in a small window. This return to manual operation not only emphasized historical continuity but also symbolized a reconnection with physical interaction in weather forecasting, especially in an era dominated by digital technology.

The weather predictor presented here from the late 20th century, produced by the Nauticalia brand, is a replica of the 19th-century weather predictor by Negretti & Zambra. It has the same design and identical forecasts that appear in a dedicated window. However, its pressure scale for inputting values is engraved in millibars rather than inches of mercury, as in the original version.