Originally Posted by Timo Nieminen
I can't tell for sure from the description whether he gives the centre of percussion (i.e., the centre of percussion as defined by all non-sword people) or the closest-to-the-tip node of vibration (which is often called the COP by sword people).
The key to what is actually measured is that last word, "vibration". I think the measurement is a measurement of the node of vibration, but I'm not certain.
Sweet spot and center of percussion are terms from Baseball. I have serious doubts, that we can use such terms for describing swords. Because the specification is quite different.
At least a Baseball bat is no static device.
Also the point of balance means not much or nothing. For example the POB of the shamshir (1kg) is ~18 cm away from the guard. On my European rapier (1kg) the POB is ~5cm away from the guard. But the Shamshir is clearly mor agile and more flexible to use than the rapier. So what does the POB says?
Theory (!): In a two dimensional coordinate system we have two axes, the x and y-axis.
If we describe the POB we use the lengthwise axis, which is normally the x-axis. But the POB on the y -axis is also important! The POB should be as close to the cutting edge as possible! This leads to a more stable blow. Maybe this is one reason for the 38 fullers, next to a lower weight.
I found out for myself, that all modern technical terms are pretty useless to describe a sword. So I tried to avoid modern technical terms in my text.
Tons of technical descriptions are nothing compared to a real test blow.
I tried out the usability of many different sword types (normally without cutting tests), so I'm pretty experienced in this field. Nowadays I can hold a sword, make some blows in the air and I can say, what it is designed for (for example once I tried out a long Afghan Kyber knife/sword and it was clear within seconds that this is a cutting weapon, despite its sharp and long point. Later I found out, that this is absolutely true).
My concluison: Modern technical terms are between not ideal and useless to describe an ancient edged weapon.