Friday, 28 May 2010
The flyers and the campaign ribbon pictured are both currently on display at Abbey House Museum in the "Park Life" exhibition until the end of December 2010.
Tuesday, 18 May 2010
An x-ray of a wheel, in this case the great wheel, from John Harrison's precision pendulum-clock No. 2, reveals some interesting details about its construction, and some hints as to Harrison's roots as a joiner in a largely rural area. First, the movement is made almost entirely of oak. There are some small components made of lignum vitae, a very dense and waxy tropical hardwood from the West Indies and Central Amercia. Its waxiness means that it has a very slippery, smooth surface. Harrison used them for friction reduction without lubrication and he probably learned about this material from ship's carpenters in Hull and on the Humber estuary.
The construction of the wheels of the Harrison clock movement is very similar to the construction of the wooden wheels seen in the machinery of wind and water mills.
The grain of the wooden teeth is aligned radially, like sunbeams. For Harrison's clock wheels and cogs this was done by gluing blanks of wood into a groove cut into the edge of the wheel, and then forming the teeth. If the wheel had been formed from one piece of wood, the teeth at the short grain parts of the wheels would have snapped off. Whilst there is no direct evidence that the Harrisons worked on windmills, the fact is Lincolnshire had hundreds of them, a good supply of wind readily available from the North Sea, to power the windmills that ground the wheat that grew in the flat lands of Lincolnshire. An interesting feature is that Harrison used very slow growing quartered oak for the main body of the wheels. The annual rings are very close together, so the wheel is both very stable and light. The wood for the teeth is, however, from fast growing oak. It is denser and therefore stronger, strength where it is needed. Harrison really knew his onions when it came to materials, an engineering approach to woodworking. My own tests comparing the weights of slow grown and fast grown oak show that the slow grown is a considerable 27% lighter than the fast grown oak. The picture below (picture credit Jeff Darken) is a cog from Harrison's precision pendulum-clock No. 2. The inner construction is shown in the x-ray at the top of this blog entry. The roller pinions are of lignum vitae. There is an earlier blog entry about this clock, search under Conservation.
A BBC documentary on John Harrison is available on iPlayer until 24/05/2010
And a Yorkshire Post article
The Science Museum's website included a section on Making the Modern World; the subject of navigation and the technologies developed to enable precise navigation and mapmaking features on the link below:
The Science Museum also has one of Harrison's earliest clocks, before he began his longitude experiments:
Monday, 17 May 2010
Here the inner carcase has been withdrawn, and another carcase within (like Russian dolls) has also been taken out.
Panels, which run in tapered sliding dovetail grooves, slide out to reveal more secret compartments.
Another panel, whose catch is released by a pin through a hole, slides away to reveal another carcase.
You can appreciate that these secret compartments can only be demonstrated as a special offer, and by someone who knows what they are doing. Part of the point of the Dummies' Guide was so that more staff at Temple Newsam House would know how to demonstrate the secret compartments correctly and safely, so hopefully this will become a regular tour feature.
Wednesday, 12 May 2010
Tuesday, 11 May 2010
Students from the clocks programme at West Dean College, near Chichester, have been undertaking condition assessments on clock movements at Temple Newsam House, under the guidance of their tutor Matthew Read. The plan is to get more of the clocks on display at Temple Newsam House into working order, to give visitors a richer experience when visiting the house.
Thursday, 6 May 2010
Wednesday, 5 May 2010
This hanging from our collection is believed to celebrate the passing of the Great Reform Act of 1832. The act was passed after many years of petitioning and popular agitation about the abuses and corruptions within the system for electing MPs. New boroughs were created, in the emerging industrial cities in the north, by taking away seats from the ‘rotten boroughs’, where hardly anyone lived. The act also widen the electorate giving more men the vote (No women quite yet!).
Although the origins of this hanging are unclear it is the imagery found on the hanging and also the history of these types of textiles that bring us to believe it is making a political statement supporting parliamentary reform. The central panel of the hanging appears to depict the heads of Lord John Russell and Earl Grey who pushed the act through Parliament. The hanging is made using a technique known as inlaid patchwork, whereby woollen cloth is inlaid and sewn together to make up the design. The technique was usually worked by tailors recycling the off-cuts of their trade. Tailors, in 1832, would had been one section of society that probably benefited from the Great Reform Act.
This hanging is currently in Bautzen, Germany as part of a touring exhibition of Inlaid Patchwork. But it will be returning to Leeds, as the exhibition is coming to the Art Gallery at the end of August.