In 1978 Bert Bolle had written a book titled ‘Barometers’, which was translated in German and English in 1980. Three years later he wrote a scientific sequel to his first book and invented some modifications in mercury barometer systems. In 1984 Bert's wife Ethne talked about starting something like a barometer museum in their 18th century country house. Bert gave it some time to think about, and the next year he thought the time was ripe to give the idea a go. His aim was to create a collection based on loans of barometers from private collectors and museums in the Netherlands. To obtain these loans, a massive publicity campaign should be the best remedy. Knowing that the press would not be very impressed by just a castle in the air, Bert decided to launch something spectacular first, an appliance that would be impressive and definitive, as the centre point of the Barometer Museum to be. When writing his barometer books, he had become impressed and inspired by the 17th century pioneers with their huge instruments. He would love to create his own water barometer! The old country house had three stories, with ample height, and above the centre of the main hall was the highest spot of the building: a leaded glass cupola of which the top part was over 12 metres from the hall floor. A perfect environment for such an enormous instrument.
Although there was no literature available about how to make your own water barometer, Bert knew in detail what had been built in the former centuries. He also had the advantage of the 20th century technology, which e.g. enabled him to abandon the lead pipes that had been used in the old days. Schott Ruhrglas in Germany made beautiful strong glass pipes in any size, and could supply a huge glass cistern too. Instead of filling the barometer from the top, a modern rotary vane vacuum pump could be used. Timer relays would make the pump alternately let the water go down in the pipe, or rise and so forth. There was a calibrated digital barometer of extremely high accuracy on the market to check the readings from the water barometer register plate. Those modern blessings challenged Bert to go on with his idea.
After a long period of investigation, Bert could started designing the barometer. Initially he made sketches and drawings by hand, later he used his Apple Macintosh computer. It is amazing how sophisticated the graphical Mac-programs already were in 1985.
Meanwhile the Barometer Museum Foundation was set up and a Committee of Recommendation was established, consisting of curators from the Netherlands and abroad, scientists in the barometer world, and last but not least former prime minister Piet de Jong of the Netherlands. It had become time to make a 'shopping list' for the water barometer.
Bert Bolle's ‘shopping list’
Bert Bolle chose a 90 mm glass pipe, consisting of four sections. Those pipes would be fitted to a huge oak plank of 9 metres height. The top 3 metres would be made in Perspex. A glass cistern of 60 cm diameter would hold 150 litres of water, enough to make the barometer work. Finding the wood for such an enormous plank was the first problem. Fortunately Bert knew a wood dealer who had just supplied a Dutch ship builder with extremely long sheets of French oak. The wood dealer managed to buy two sheets back, and offered to make the plank according to the design. Schott Ruhrglas in Germany came with generous quotations for the pipes and the cistern. Finally Bert had his 'shopping list' ready:
One French oak plank being about 9 M long, about 40 cm wide, abut 40 mm thick, and about 1 M wide at the base.
One steel top cover for the plank mentioned above.
One Pyrex glass cistern manufactured by Schott, Germany, 60 cm diameter.
One Pyrex glass cover of 12 mm thick, in two parts, for the glass cistern.
One rubber seal for the cistern cover.
One analogue and one digital thermometer for the glass cistern.
One aluminium stand for the glass cistern.
One circular collar with oak finish in two halves to fit around the stand of the glass cistern.
Four Pyrex glass pipes being 9 cm thick, three of them being 3 M long, one of them 2.50 M long.
One Pyrex glass cap for the top pipe.
Four aluminium fitting sets with rings for the flanges of the glass pipes.
One steel bracket to hold the pipe system.
Various small stainless steel parts, e.g. bolts, nuts, washers and rings.
One transparent Perspex plate of 3 M long, about 40 cm wide and 25 mm thick.
Two Perspex brackets, 25 mm thick.
One 6 mm thick white Perspex register plate, same size as the Perspex plate above.
One rotary vane vacuum pump, manufactured by Leybold Heraeus, Switzerland.
One Secuvac safety valve, manufactured by Leybold Heraeus, Switzerland.
One water detecting safety device.
One computerized multi-channel timer.
One camera plus monitor.
One relay cabinet.
Various cables.
A lot of money was saved, as Bert did a lot himself, and there were some good friends with helping hands. In total over 600 hours were involved to get the barometer completely installed and working. Fortunately the companies who supplied the materials, tried to help the Barometer Museum Foundation with discounts, but nevertheless over 10,000 Dutch guilders needed to be spent. Nowadays, if the barometer should be totally rebuilt, all materials would cost between 15,000 and 20,000 Australian dollars, not counting the hours and the fact that the German glass factory will stop producing their special industrial Pyrex glass pipes and cisterns within a couple of years time.
From mid 1985 all materials were acquired and prepared for their final use. In November of the same year, the barometer was erected and made its first test run.
