Princes Street tram works bus diversion map #Edinburgh

Princes Street will be closed to buses from 3rd September 2011. The closure will be in place till June 2012. The main difference to previous closures is that The Mound will also be closed to buses. This means that services like the 23 and 27 will be going via Waverley Bridge and St Andrews Square.

You can download a map showing all the temporary stops in George Street showing which services stop where here (single A4 sheet - pdf file):

Princes Street Bus Diversions Map

Can't print in Chrome - solution

My copy of Chrome has been refusing to print in Google Documents. The print preview doesn't work and I get a message saying that the Chrome PDF Viewer needs to be enabled. When I checked it was already active. I tried disabling and enabling it again, but that did not help. I then enabled the Chrome NaCl plugin and that fixed it. You will find it in the plug in list near to Chrome PDF Viewer. I suspect that this might be because the new preview system runs natively in the browser.

Hope this helps someone else.

What is the difference between a trumpet and a cornet?

Cornets and trumpets developed from different origins. The trumpet developed from the natural trumpet, which eventually had valves added to it. The cornet is derived from the french post horn which had stoelzel valves fitted to become the cornopean, before having modern valves and becoming the cornet. The cornet had valves about 30 years before the trumpet did. The cornet was always in higher keys such as C, Bb and A. The first valve trumpets were in F or E or Eb (lower pitch than a modern Bb trumpet). At this point trumpets had a greater proportion of their length cylindrical bore compared to the cornet which was more conical, but when trumpets started being built in Bb and A (the same pitch as cornets) there was very little difference in these proportions. Some of the earliest Bb trumpets were originally sold as "cornets" because trumpet players were not keen on moving from the big F trumpets they were used to. Manufacturers then started making Bb trumpets made to look like F trumpets with false, unconnected, tubing to make them look bigger.

I recently measured three cornets and a trumpet to see how much of them was conical and cylindrical bore. You can see the results here. The differences were marginal. The main difference is the shape of the bell flare and how it flares out rather than the proportions of cylindrical to conical bores. Long model cornets have bells more similar to trumpets. Some trumpets (e.g. the Wild Thing) have bells which are more similar to cornets.

Modern cornets and trumpets are very similar and not really separate instruments at all. The main thing which makes them sound different is the mouthpieces used. Cornet mouthpieces are usually conical like a french horn mouthpiece and trumpet mouthpieces are cup or bowl shaped, giving a brighter sound.

Update: Someone has drawn my attention to this article and its accompanying measurement chart which seems to support my assertion that the proportion of cylindrical to conical is not significantly different between trumpets and cornets.