For sale, an early Victorian rosewood stick barometer with double Vernier and bone float by JB&J Ronchetti of Manchester. This rare instrument is constructed of quality rosewood with a square moulded pediment above a v sectioned scale plate with gothic style engraving reflecting three weather indications, Fair, Change & Rain and showing 27 to 31 degrees of barometric pressure. Above is engraved the makers name of JB & J Ronchetti. This feature allows for the left hand Vernier to be set on a certain day and the right hand Vernier to be set on the other side at the following days reading.Thus it allows the owner to keep an accurate record of the ongoing changes to the weather. Below the glass fronted scale plate are two bone knobs which operate the Vernier markers (both replacements) and below them is a removable thermometer with silvered scale showing readings for both Fahrenheit & Reaumur. The rosewood cased and glazed fronted thermometer was intended to be removable to allow the user to measure temperature in different areas of the household as required.
The base of the barometer has an urn shapes cistern cover with its original bone float. These floats are a seldom encountered feature on stick barometers and only found on the highest quality examples. Thought to have been invented by the famous instrument maker, Jesse Ramsden, the float was considered to be a solution to eliminating errors in the cistern level of the barometer and to zero balance the scale for correct reading. The brother makers John Baptist & Joshua Ronchetti were third generation Italian immigrants whose family settled in Manchester in the late eighteenth century and began to trade as scientific instrument makers. Originally living in Tavernerio in Italy, they were one of numerous Italian families that moved to England during the period.
The brothers took over their fathers business (Charles Joshua) in the late 1830s after he went on to set up a weather proofing factory in the Clayton area of Manchester. The brothers according to a notice in The London Gazette had previously formed a partnership which was dissolved in 1837 and had been trading from the centre of scientific instrument making in London during the period at No. 2 Hatton Gardens, very close to where Negretti & Zambra would open for business thirteen years later. It suggests that the offer of their fathers business at 43 Market Street, Manchester was a better opportunity than their dealings in London and they continued in business until 1851 whereafter it is thought that they then took over the weather proofing factory.
This is a superior quality instrument dating to circa 1840. Jason Clarke Antiques are happy to discuss carriage, condition or for any other queries, alternatively, you can also message me and I will endeavour to come back to you as soon as possible. I have a number of beautiful antiques for sale, so please feel free to browse my other items. The item "VICTORIAN ROSEWOOD STICK BAROMETER WITH BONE FlOAT BY JB&J RONCHETTI MANCHESTER" is in sale since Wednesday, November 8, 2017.This item is in the category "Antiques\Science/Medicine\Scientific Instruments". The seller is "jason750_1" and is located in newbury, Berkshire. This item can be shipped to United Kingdom.