This article was published in the Winter 2005 issue of the BVMA newsletter. There are 4 pages.

Divide and Rule

In the first of a two-part article, Hans Pluhar observes Stradivari's drawings and measurements, and tries to answer some of the questions he raises.

The original idea for this article was to write about my experiences using Stradivari's method for placing the eyes of the f-holes in my own making. I was then going to add a little comment on his original drawings. But in the preparation for this article, I became more involved and it was apparent that it was a more complicated matter than just writing a little comment. That's why I've decided to write two separate articles, this first one, my observations about the Stradivari f-hole placing drawings and, at a later stage, about my adaptation of this system.

The more I study the drawings, as shown in Stewart Pollen's book The Violin Forms of Antonio Stradivari, the more questions arise, and certainly more questions than answers. But there are one or two interesting details I found that I would like to share with you. Maybe it's easiest stating the obvious first. The drawings I'm talking about (illustrations 28 to 33 in The Violin Forms) are actual tracings of rib structures, not of a mould. You can see this best and most easily when looking at the corners where sometimes the two lines don't join up, and the thickness of the rib mitre is shown. The drawings show the positions of the eyes of the f-holes in relation to the outline. This could be for documentation for future use or simply to be able to take some divider measurements off the drawing for use in placing the actual f-holes on the top. But the principle is straightforward, I think. Changes from model to model or from violin to violin can be made very easily by altering any of the parameters independently of each other.

The problem, though, that has puzzled me for a long time is that the measurements within the sketches don't seem to make that much sense. They don't seem to match up with the moulds also shown in the book. The moulds are very exact photographs of the originals. Of course, shrinkage may have occurred over the many years since they were made, and also the size of the paper changes with time and humidity. As Pollens explains when he writes about how the photographs were taken, the paper drawings couldn't be placed under a sheet of glass to shoot them absolutely flat, neither could the original measurements be taken. Therefore it was difficult to enlarge them to life size. When it came to the measurements in the enlarging process, they had to rely on tracings of the paper patterns that Sacconi had made. So until we know the real measurements for certain we will be left in the dark.

But for now, I'm going to work on the basis that they are pretty close to original and take it from there. At first sight the G-form drawing is the most useful for studying purposes. It is preserved with both left and right side and has no ink drawings that could cover up any useful information such as divider or compass markings (these are represented in the drawings as pin prick dots). In Fig. 1 I have given numbers for easy reference to the most obvious and important pin pricks. The most obvious problem here seems to be the width of the bouts. They seem too wide. Second, the marked line in the middle does not represent the centre of the rib structure. It is quite far off, about 3 mm on the top and 2.5 mm on the bottom.