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Object Overview
The surveying aneroid barometer, crafted around 1880 by J.H. Steward, exemplifies a remarkable blend of engineering and functionality. Its brass casing, painted black, conveys a sense of rigor and durability, embodying the spirit of precision and the challenges of field research.
An adjustable rotating magnifying glass along the entire rim draws particular attention, designed for the most accurate reading of the scale — an intricately thought-out engineering solution. Moving along the serrated edge, the magnifying glass allows the viewer to see even the smallest scale divisions with incredible clarity.
The barometer is equipped with a vernier, operating on a rack mechanism and controlled by a knob positioned on the top of the device. This setup provides the finest adjustment and measurement accuracy, enabling the surveyor to capture each subtle atmospheric change even in challenging conditions.
The dial, crafted from vitreous enamel, features two scales: a barometric scale in centimeters of mercury and an altitude scale in meters ranging from 300 meters below sea level to 3000 meters above sea level. This dual scale highlights the instrument’s versatility, perfectly suited for cartographers and surveyors, allowing them not only to record atmospheric changes but also to precisely determine altitude above sea level. This aneroid barometer stands as a testament to the fusion of art and science, where masterful craftsmanship meets practicality to create tools that help explore the surrounding world with utmost precision and attention to detail.
7214
aneroid capsule tensioned on a C-spring
brass, enamel, glass, nickel silver, steel
This barometer is not only a testament to precise engineering but also to specialized design aimed at capturing subtle shifts in gradients, levels, and more. Surveying barometers like this one were specifically developed to easily detect minor changes, making them invaluable for approximate surveying and leveling work along roads, railways, canals, waterways, and mines, where readings needed to be taken quickly and accurately.
The mechanism of these instruments is compensated and manufactured to the highest standard, eliminating any slack in the indicator needles and ensuring stability. This particular model, with its black-painted brass casing and adjustable magnifying glass, represents the pinnacle of surveying precision. The magnifier, moving smoothly along the serrated rim, aids in the exact reading of the dual scales on the silvered brass dial, with barometric measurements in centimeters of mercury and altitude in meters up to 3000 meters.
Controlled by a handle on top and equipped with a vernier on a rack mechanism, the barometer allows for the finest adjustments, ideal for surveyors in the field. These barometers were constructed to withstand rugged conditions while offering uncompromising accuracy, helping engineers and surveyors track even the slightest atmospheric changes, essential for the meticulous work of shaping and understanding landscapes. This surveying barometer, in its masterful fusion of art and science, is as much a scientific marvel as it is a piece of enduring beauty.
J.H. Steward was a British company founded by James Henry Steward in London in 1852. It specialized in the production of optical and scientific instruments, including microscopes, telescopes, compasses, and barometers. The company also manufactured devices for military purposes, such as instruments for reconnaissance, night marches, and artillery targeting.
In 1913, the company was registered as J.H. Steward Limited. Its products were in demand among British and foreign governments, as well as by the National Rifle Associations of England, India, Canada, and the colonies.
In 1975, the company ceased operations permanently.