Exceptionally Rare Barograph

This is one of the very few surviving barographs of this unique design. Manufactured by CB Goerz of Berlin circa 1920, its principal advantage is that it records on a continuously rotating chart with a set of magnets behind. The diaphragm stack is linked to a fine chain which is held by the magnets and are then moves on the chart in sequence with the barometric pressure. There is also a barometer dial, in millimetres linked to the same movement. After seven days the chain will reach the bottom of the the chart and start recording again from the top.  A much more detailed description of the instrument can be found in Philip Collins' book on Barographs. The one illustrated in his book (see pics) is now owned by a respected colleague.  I acquired this particular instrument about 25 years and it came with what can only be described as a 'commercial' wooden case (as shown in the picture). I would imagine this would have made and installed in a public or scientific office. I commissioned  the beautiful polished oak case (at £1200) to match as close as possible to the diaplay model.   Ideal for a specialist collector with the ability and time to fine tune the instrument and set it working again.