My study of Adolphe Sax's instruments and other instruments from the 19th century has made it clear that saxophone necks were shorter at that time. Wide-chambered mouthpieces were in common use, making an obvious fit to the then larger truncation.

This is kind of an offshoot from my study into the history of saxophone bore profiles. In order to arrange the instruments, ancient and modern, in a graph vertically correctly over one another, it was necessary to do this not by aligning them by neck entrance 1, but by tone hole positions. When I did this, it turned out that necks were not at all of uniform length. On the contrary: the necks of the older instruments turned out to be shorter than those of the modern! The accompanying shift to a narrower mouthpiece also begins very early. Already in the later 19th century mouthpieces start to get narrower. Not with big steps, but nonetheless.

As far as I now can see, there is not any clear point in time or well defined development in the process. Yet, when we arrive in the mid 20th century in France the shift is obvious; the American saxophone being somewhere in between the 19th century and the modern. The Asians follow the French. It goes for all types of saxophones (S, A, T, B), but not to identical proportions 2.

If you're familiar with historic saxophones, you might have noticed that the old sopranos look really short and, like the altos, carry only a wee bit of cork on their necks. If you have a sensitive eye, you might have noticed the neck of the 19th century altos to be both a little bit thickish and on the short side. Likewise, you might have noticed that the old baritone seems to have a smallish crook compared to the present. At the same time, the upper bow starts right above tone hole 20 for Eb3 – as it does to this day.
The drawing on the right illustrates what is going on. While the total acoustical length remains the same for the original saxophone (on top) compared to the modern (below), there is a shift in length of the instrument itself. The red glob represents the mouthpiece, replacing the truncated black part of the cone. We note that the mouthpiece volume decreases proportionately to the increase in length of the instrument, the overall total remaining the same.
Apart from a great many mechanical differences between the historic saxophone and the modern, this shift in neck length, combined with the shift in mouthpiece volume is a major feature in the difference in the acoustics between the original instrument and the modern.

A 19th century Royet soprano and the Buffet-Crampon S1. The instruments are aligned by tone hole position. It is obvious how much shorter the neck of the older one is.

but why?

You might wonder about the reason for such a remarkable shift in instrument design. There is a number of reasons. A neck needs to hold the pressure node of the highest playable note. Both the soprano and the baritone originally were keyed up to Eb3 only and their necks just covered that range. So for both these instruments the neck just had to get longer when keys to F3 were added. The same holds true for the addition of the key for F#3. But another and probably more important reason is intonation. A longer neck offers a better control over correct intonation, especially of the higher range. Since intonation was a subject of critisism in the early decades of the saxophone, a longer neck came as a blessing. Various builders after Sax experimented with it. Already in the 19th century a somewhat narrower mouthpiece came along with it.
The price to pay was a more slender tone, some loss of dynamics and richness in lower partials – what had been a major selling point of the saxophone in the first place. Now of course I wanted to test this in practice...

Which is what I do in practice when measuring a saxophone. For length measurements you simply have to take a zero somewhere...

I'm redrawing my bore profiles at the moment in order to make this development visible. As for the shift in mouthpiece design, please consult in the MEASUREments section the pages on the beginnings of mouthpiece manufacture.