Category: Pressure

Hysteresis and the Watkin Hicks Mountain Barometer
Aneroid, Barometers, Barometers in Action, History of Aneroid Barometers, How do I repair an aneroid barometer, Is my barometer working, Pressure, Surveying, Technology, Testing Barometers, Vavasseur Antiques - Antique & Vintage Aneroid Barometers, Barographs & Other Scientific Instruments, Weather | August 28, 2023
Hysteresis and the Watkin Hicks Mountain Barometer
This scarce development of the aneroid barometer or altimeter, patented by Colonel H.S.S. Watkin in 1898, was born of poorly performing pressure sensing capsules. It had been known for some time that a first reading before an ascent of some high place would not agree once the observer returned to the same elevation even if the barometric pressure had not...
August Work in Progress
Aneroid, Barographs, Barometers, Conservation, History of Aneroid Barometers, How do I repair an aneroid barometer, Pressure, Restoration, Vavasseur Antiques - Antique & Vintage Aneroid Barometers, Barographs & Other Scientific Instruments, Weather | August 8, 2023
August Work in Progress
Another fine instrument of particular interest, this large barograph is something quite special, and although unsigned, is undoubtedly the work of Negretti & Zambra. Let’s examine the evidence for this. First, the instrument is listed in the Negretti & Zambra catalogue of 1910 in the section Self-Recording Aneroid Barometers: item 82, a “Self-Recording Barometer, with a tall cylinder taking a...
The Quest for Greater Resolution in Aneroid Barometers II
Aneroid, Barometers, Barometers in Action, History of Aneroid Barometers, Pressure, Restoration, Testing Barometers, Vavasseur Antiques - Antique & Vintage Aneroid Barometers, Barographs & Other Scientific Instruments | August 6, 2023
The Quest for Greater Resolution in Aneroid Barometers II
As a follow up to Patent No. 2457 lodged by Daniels, this piece is certainly of significance. The Daniels instruments sought to display greater resolution with the introduction of a geared sub-assembly greatly magnifying the small rotational movement of the primary arbor, that connected by a fine chain to the secondary lever - the result being that the main dial...
Two Extraordinary Altimeters, and the Trail to the British Nuclear Bomb
Aneroid, Aviation, Barometers in Action, Conservation, Featured, History of Aneroid Barometers, Pressure, Restoration, Technology | July 24, 2023
Two Extraordinary Altimeters, and the Trail to the British Nuclear Bomb
Sometimes the most obscure and almost unrecognisable objects appear, and with all the interest in Christopher Nolan’s epic docu-thriller Oppenheimer,  I decided to put pen to paper. Some years ago I was perusing an online auction and came across an instrument I recognised as a barometer or altimeter made by Negretti & Zambra. Puzzling, though, was the scale, calibrated in...
The Quest for Greater Resolution in Aneroid Barometers I
Aneroid, Barometers, Barometers in Action, Conservation, History of Aneroid Barometers, Pressure, Restoration, Surveying, Technology, Vavasseur Antiques - Antique & Vintage Aneroid Barometers, Barographs & Other Scientific Instruments | May 11, 2023
The Quest for Greater Resolution in Aneroid Barometers I
As marvellous an invention as the aneroid barometer was, it had many shortcomings, most of which were approached by various instrument makers over the 100 years or so of production. Resolution, perhaps expressed as the reading to the highest number of decimal places, was an illusive goal. The problem relates to the expansion and contraction of the cell over a...
Conservation & Restoration Services
Aneroid, Barographs, Barometers, Barometers in Action, Bourdon, Compasses, Conservation, How do I repair an aneroid barometer, Is my barometer working, Pressure, Restoration, Technology, Testing Barometers, Vavasseur Antiques - Antique & Vintage Aneroid Barometers, Barographs & Other Scientific Instruments | April 28, 2023
Conservation & Restoration Services
Barometer repairs or restoration services? We undertake barometer and barograph repairs, restoration and servicing at reasonable rates. We handle aneroid and mercury barometers, barographs, and other scientific instruments. “I had two early instruments which were ‘showing their age’ and needed rejuvenating without losing any of their original looks.  The team at Vavasseur would appear to live and breathe pocket instruments and I would recommend...
Antique Pocket Hypsometers II - Hicks Hypsometer
Aneroid, Barometers, Barometers in Action, Conservation, History of Aneroid Barometers, How do I repair an aneroid barometer, Is my barometer working, Pressure, Restoration, Testing Barometers, Vavasseur Antiques - Antique & Vintage Aneroid Barometers, Barographs & Other Scientific Instruments, Weather | April 22, 2023
Antique Pocket Hypsometers II – Hicks Hypsometer
A very  rare leather cased, lacquered and oxidised brass hypsometer No 590 by J. Hicks, London, c1900 Comprising four draw telescopic top section, the third draw marked "J. Hicks, Maker, 8, 9, & 10 Hatton Garden, London, No 590," first draw with heat shroud. Spirit burner with integral pushfit end cap, threaded wick cover, wind and flame shroud with lower...
New Test Control Unit in Laboratory
Aneroid, Barographs, Barometers, Conservation, How do I repair an aneroid barometer, Is my barometer working, Pressure, Restoration, Technology, Testing Barometers, Vavasseur Antiques - Antique & Vintage Aneroid Barometers, Barographs & Other Scientific Instruments | April 21, 2023
New Test Control Unit in Laboratory
An addition and a development of the Calibration & Flow Control Unit Mk1 The lack of availability of this equipment commercially left me with no alternative other than to design and build in-house. In any event I had my own ideas and requirements. This control unit manages a number of parameters in a readily visual way leaving aside the need...
Antique Pocket Hypsometers I - French Hypsometer
Aneroid, Barometers, Barometers in Action, Pressure, Technology, Testing Barometers, Vavasseur Antiques - Antique & Vintage Aneroid Barometers, Barographs & Other Scientific Instruments, Weather | April 12, 2023
Antique Pocket Hypsometers I – French Hypsometer
The term 'Hypsometer' is essentially applied to a device or system, perhaps mathematically based, that enables the determination of heights or elevations. It has been applied to aneroids and various trigonometrically based instruments. In this instance we are dealing with the instrument more generally recognised as a hypsometer, in essence a device not unlike a telescope however lacking lenses, the...
March Work in Progress
Aneroid, Barographs, Barometers, Bourdon, Conservation, History of Aneroid Barometers, Pressure, Restoration, Vavasseur Antiques - Antique & Vintage Aneroid Barometers, Barographs & Other Scientific Instruments, Weather | March 31, 2023
March Work in Progress
Another fascinating instrument from the storeroom, and at last I can give it the attention it needs. This Negretti & Zambra barothermograph was absolutely filthy, caked in dust and grime, and working to a point but not much more. Nonetheless, I could see that this would come good with careful conservation techniques. I always start a project like this by...
February Work in Progress
Aneroid, Barographs, Barometers, Barometers in Action, Compasses, Conservation, History of Aneroid Barometers, How do I repair an aneroid barometer, Is my barometer working, Pressure, Restoration, Testing Barometers, Vavasseur Antiques - Antique & Vintage Aneroid Barometers, Barographs & Other Scientific Instruments, Weather | February 16, 2023
February Work in Progress
Many might wonder what might be next on Vavasseur Antiques. “Work in progress” is a constant state, since almost all the items we offer are comprehensively re-built, serviced, and/or benefit from conservation. Consequently through-put is sometimes slow. This does mean though that the things we offer are ‘proper,’ as described, and as original as possible, not the product of the...