Derek & Tina Rayment Antiques

Teaching young dogs old tricks

Nearly every week we have phone calls from people who have found us on the internet and enquire if we are able to help them as their barometer has suddenly stopped working and they are desperate without it.

Of course we are delighted to do so and in most cases it is a very simple and straightforward repair and adjustment that rescues the situation. It is interesting to note that in these instances the client really does use and depend on their barometer because over the years everyone seems to have switched to modern technology and the TV weather forecast. This has in most cases made the antique barometer just a decorative object. However if you go back in time to when these domestic instruments were made in the thousands, they were, at that time, an essential item just as important as the timepiece.

A very interesting development has taken place recently with the Met Office publicly requesting that they need help and information from individual owners of weather instruments, so that their forecasting can be more accurate and localised. We are so used to images on the television of warm fronts and cold fronts rushing across the screen, with isobars and wind direction, rain clouds etc, that most people disregard their own barometer as being inadequate. However, at last the powerful Met Office have realised that local information is vital to get an accurate forecast.

Let us consider the aneroid barometer which was invented in the mid 19th century specifically because it is smaller and more portable, and indeed more accurate as a scientific instrument. The whole point about the aneroid is that you can easily adjust it to obtain an accurate reading of the air pressure.

Air pressure drops at a fixed rate, basically 1/10th inch for 100 feet. If the pressure at sea level is 30 inches, at 500 feet it would be 29.50 inches. This makes a lot of difference to the reading and forecast on the barometer dial, and in order to get an accurate forecast the first thing to do is to reset the reading, if necessary.

To get a local pressure reading, go online and google ‘atmospheric pressure’ and your locality or nearest town. It is possible that the reading given may be in metric, so you will need to convert that into inches. If necessary we can help here as we have a conversion chart, the reason being that a barometer dial is graduated in inches.

It is very easy to reset the reading as there is a set screw on the back of the case, behind the dial and a small screw driver can be used to turn the set screw head, which will turn the hand on the dial. Once you have an accurate reading of the pressure the barometer will sit on the wall and work away happily.

The reason the Met Office are asking the public to get involved is that weather is affected by local conditions. The air temperature is often higher in highly populated areas. Altitude and local terrain is also a factor, affecting wind direction and pressure.

When the Victorians made the huge quantity of domestic barometers, there was no TV or radio, and it was intended to be a local forecast of a very simple principal. High pressure and a rising barometer foretold good weather, and low pressure and a falling barometer foretold changeable and unsettled weather. Again it must be understood that it is a forecast of what will happen in the next 12 to 24 hours, not necessarily what is happening outside at the moment you check your instrument.

In conclusion it is a pleasant thought to realise that the Met Office have at last acknowledged that the domestic barometer is not just a decorative object, but if set up correctly can be an important addition to their own service.

Teaching young dogs old tricks