Laying out the pins on the neck of the harp

In 2011, Michael Billinge wrote an interesting observation on the layout of the tuning pins on the neck of the Downhill harp. Talking about the way the tuning pins become more spread along the cheek band, as the angle of the neck becomes higher in the bass, he writes: “instead of an even change across the range, as might normally be expected, he seems to have done this in a series of blocks or groupings”

In his footnote, Billinge gives a list of the gaps between adjacent pins, and the way that they increase in steps. My chart below gives a visual representation of his data:

Pins spacing on the neck of the Downhill harp (mm) (data from Michael Billinge)

What made me think of this was that I was doing the same work this week on the Carolan harp. I tagged points on the laser-scan corresponding to the cheek-band holes in the left side (string side) cheek band, and then calculated the distance between each one. Plotting a graph of these distances showed clear groups of similarly-sized spaces.

Tuning pin spacing on the neck of the Carolan harp (mm)

Billinge does not say what the error margin on his measurements are, and so it is difficult to analyse them further. On the Carolan harp, the error on the picked points is less than 0.1mm, but the selection of what points to pick is much less accurate than that, since the scan is quite messy around the tuning pin, with lots of scanning artefacts. I would estimate the accuracy of my measurements as perhaps ±1mm

You can see on my graph that there is a certain amount of zig-zagging, alternating around an average value. I saw this also on the spacing of the string shoes on the belly, but I explained that as an artefact of the alternating shoe design. I’m less sure how to understand this alternating spacing on the neck.I have not done such a detailed measurement of any of the other harps, but the point positions of the tuning pins as used to generate the string charts for the Kildare and the Mullaghmast harps can be used to analyse the pin spacing. The accuracy here is perhaps more like ±3mm. The Kildare seems to show some evidence of grouping, but the Mullaghmast pins are clearly spaced incrementally, with each pin a little further from its neighbour than the previous one.

Pin spacing on the neck of the Kildare harp (mm)


Pin spacing on the neck of the Mullaghmast harp (mm) (cropped, the largest spacing is 116mm)

We could follow Billinge by averaging each group on the Carolan harp, and calculating a standard deviation from the average:

Pins 1-3: 17±1.5mm
Pins 3-6: 14.5±6mm (too erratically placed to say much)
Pins 6-12: 13±1.5mm
Pins 12-19: 14.5±1.5mm
Pins 19-26: 18.5±1.5mm
Pins 26-30: 22±1mm
Pins 30-32: 26±1mm
Pin 32-33 crosses the opened neck-pillar joint.
Pins 33-36: 28.5±1mm

I think this kind of analysis can give us ideas about the working methods of the old harp makers. We can imagine the makers of the Downhill and the Carolan harp, working with dividers to lay out groups of pinholes on the metal cheek-band, as well as using dividers to lay out the string-shoes equally spaced on the soundboard.

What then of the Mullaghmast harp, with its progressive spacing? A different school of harpmaking?

My header photo shows a rendering from the laser-scan, showing two points picked for holes 9, 8, 7, 6, 5, and 4. The position of each hole was calculated as an average of the positions of the two points. The background grid is 1mm x 10mm. The messy damage around hole 3 and the break in the neck is visible in the top-right corner.

3d photography as a measurement tool

The bass end of the Carolan harp (which was sometimes called the Rose Mooney harp) is very damaged, and there has been a lot of movement inside the bass joint. However it’s not possible to measure this movement from the outside, because of the later repairs with iron straps and canvas bandages completely covering this part of the harp.

I had an idea to try and make stereo pair photographs of this part of the harp, to see if I could use them to measure the amount of movement both downwards (towards the bass end of the soundbox) and backwards (towards the back of the harp).

Continue reading 3d photography as a measurement tool

Harpe bardique

I have been discussing stringing possibilities of a harp made by a French harp maker, supposedly as a copy of one of the old Gaelic harps. Analysing its string lengths I noted that its scaling was suspiciously slow.

(Scaling is the technical word used to describe the ratio of string lengths across the range of a harp or other stringed instrument; a slow scaling means the strings increase in length more gradually as you move from treble to bass.)

Then I remembered that I had come across this slow, even scaling before, on harps modelled after the “Bardic harp” of Gildas Jaffrennou.

Continue reading Harpe bardique

Opening up the harp

I have been thinking for a few years now about the shape of the inside of my harp, in light of the new information we have from Karen Loomis’s PhD research at the University of Edinburgh.

When I commissioned the harp from Davy Patton in 2006-7, the thing we were most lacking was info about the inside – the shapes of the joints, and the profile and thickness of the soundbox. Basically, we had to make a lot of educated guesses.

Since then, we have the CT-scans and other technical studies of the Queen Mary harp that Karen has been working on, and many of our guesses have turned out to be pleasingly correct, such as our choice of timber – willow for the soundbox, and a bent limb for the pillar – but we were quite wrong in our decisions on how to shape the soundbox interior.

Luckily, we had erred very much on the side of leaving the wood too thick, so last week I took the harp to Natalie Surina, of Ériú Harps in Oughterard, Connemara, for her to cut a lot of wood from inside the soundbox.

Continue reading Opening up the harp

“Like medieval clockwork” – copying the missing Queen Mary harp iron tuning pins.

When I was commissioning my replica of the Queen Mary harp in 2006, I paid attention to the 30th tuning pin, which is obviously a later addition, shorter, made of iron, split end, different drive, and off the main row. This pin is now missing but I made a copy of it based on descriptions and old photos. I made the 29 brass pins with their scores on their shafts copying the museum photo of the 21 pins now in the harp, and for the 8 missing pins I made the same design of brass pins without scores.

If I had been more on the ball back then I would have noticed that those same old photos and descriptions I used for the 30th pins, also show the missing 8 from the main row, and those missing 8 are plain iron not decorated brass, and 5 of them have split ends.

So today’s project was to make 8 handmade iron pins, and install them in the harp. The contrast of the iron and brass pins is subtle but interesting in appearance, reminding me of my initial reaction to the handmade decorated pins: “like medieval clockwork”.

I broke the lowest gold B string taking it off but there was enough spare to rewind the toggle and reuse it. The string had thinned where it went over the pin – presumably a gradual process over seven years since I fitted it in 2007.

Pins

The past week or two have continued the making things theme. I have done a series of tuning keys as test-runs; I have made a page advertising them which I will send out for my 1st May Emporium Update.

I also have made the set of pins for my HHSI Student Downhill harp, and today while it was here with my student who has it, I fitted the pins – pulling each of the old steel pins out in turn and then replacing it with a new brass pin. I had to shim all of the brass pins because for some reason they are marginally smaller than the steel pins, and I used thin brass sheet to make the shims. Plenty of the antique Gaelic harps have brass shims in their pin holes and I find it works well.

We instantly noticed how much better the harp worked to tune, with the new pins – the key fits much more snugly on the new pins with their tapering drives, giving a much more positive touch to the tuning. And the new pins look rather good with their decorated drives. I am very pleased with the result.

I have always thought that handmade pins with tapering drives work so much better than machine made steel pins with parallel drives, but inertia has meant I have not bothered doing anything about it until now. Hardly anyone has handmade pins on their harps, even top players with quality decorated instruments. I can only think of 3 or 4 off the top of my head.

I am going to make a few more pins and then I think I will make a page advertising them for sale for the 1st June update! I think that this would make a fantastic upgrade to anyone’s harp, to replace the pins!