Clinton 1851 Model Flute Analysis
This analysis stems from a restoration project on a very rare flute by the mid 19th century English maker Clinton. The instrument is believed to be of the type that Henry Potter entered into the Great Exhibition in London in 1851 on behalf of Clinton. You may first wish to read the associated article about Clinton before proceeding with the analysis.
What can we expect to see in the Clinton?
From the historical record, we expect to find a conical flute, fingered essentially the same as were other conical flutes of the time. But we expect to see the known defects of the 8-key flute dealt with, and the good points retained. It would do us well to review the features and failings of post-Nicholson 8-key flutes before we see how Clinton fared.
Previous improved systems
Several systems had been invented post Nicholson to improve on the common 8-key. We should review the directions they took ...
Boehm's 1832 Conical
While making dramatic improvements to the stretch and intonation problems, this instrument was not popular in England. Detractors complained about its unfamiliar fingering and weak tone.
Siccama's 10-key design kept all the best 8-key features, improved intonation generally and reduced stretch. It was a very influential instrument, and lead ultimately to the Pratten's Perfected design of 8-key. It did not deal with the flat C# and F# notes, nor offer significant improvement to the third octave response.
Some later manufacturers of the Siccama system added a Brille mechanism to improve the C#. The Brille consists of a duplicate upper c hole closed when either or both of L1 or L2 are covered.
Boehm's 1847 Cylindrical
This is the instrument that caused Clinton to get into flute development in the first place, so it's of particular relevance. We find that Boehm's ingenious invention has solved all the technical failings of the 8-key. So why was Clinton unimpressed? For the same reason that many of us are today. The new cylindrical design brought a markedly different tone to the flute. Instead of dark and focussed, the new tone was bright and open. The mechanism was also no doubt frighteningly complex to those familiar with building and maintaining 8-key and similar designs, adding considerably to cost. It was also more intrusive and noisy.
So, How's the Clinton?
That's the question. We'll get to it below, after we examine the instrument closely.
An examination of the subject
Let's look closely at the flute to see how it might work.
The Clinton 1851 model flute with the Rudall Rose Patent head.
What did we find?
Firstly, a major dilemma. While the body proclaims:
and the Foot agrees:
the barrel argues:
RUDALL & ROSE
More to the point, the head is unmistakably a Rudall & Rose Patent Head. So was this normal, an option, a replacement or a mistake? Determining that would have to wait for the restoration.
Turning now to the body and foot, we find a lot of the key-work is straightforward:
More interesting stuff is happening in the upper axle group. There are four holes, which correspond to the notes C#, B, a sharp Bb and A. Note that these are in addition to the usual side-mounted C and Bb keys mentioned above.
Closer examination reveals:
Note also the third hole, partially obscured by the touch for L3. It is normally open, and closed by either L1 or L3. It is mounted a little higher on the flute than the Bb hole and is also distinctly bigger than that hole. It appears intended to provide added venting to C and C# notes. It will be interesting to see what improvements this might bring.
The overall system
The schematic diagram below illustrates the overall system used in Clinton's 1851 model. The ring key on L1 and the key to the left of L3 (both shown in blue) are connected together by being pinned to the key-shaft.
(Schematic diagram by Tim Gallagher, Seattle)
The rule at the top of the schematic marks where the vents for each note are placed. The large gap between E and the foot notes suggests we will see some flat-footedness in the response.
Fortunately, with the exception of the missing bits, the body of the flute was in good condition. The story of making replacement keys and pads can be found at Broken and Missing keys, Impossible pads. For reasons that will become apparent, we won't go into the details of the repairs to the head here, but at The Rudall & Rose Patent Head.
Remaining restoration involved freeing up jammed keys, replacing worn cork tenon wrappings and key buffers, and resoldering a loose axle tube on the Eb key. A replacement insert for hole L2 also had to be devised. Fortunately, the dimensions of the cavity and ring key pretty much dictated what this had to look like.
With the restoration out of the way, attention could turn to determining how good a flute this was ...
The Patent Head Mystery
The big question of course was "Did the Patent head by Rudall & Rose really belong to this flute?" Was this normal, an option, a replacement or a mistake?
There were no visual clues apart from the makers' names:
Examining the intonation produced by the pair tells another story:
The blue 470 Hz trace is the response with the slide closed, the yellow 440 z response with the slide fully extended (31mm) and the pink 455 Hz trace with the slide set halfway.
Clearly the fully closed performance is unacceptable:
With the slide fully extended, the response at 440 Hz is much better, but still not good. All indications are we need to go still lower. This is consistent with our understanding of pitch at the time - the options were High Pitch at over 450, or Low Pitch at 430.
Backing up this objective evidence was the performing qualities of the combination. Although all leakages and other problems had been ruthlessly rooted out, the flute performed very poorly. The reason for this is clear and significant. It has to be remembered that, as a Patent Head slide is moved, the stopper is moved at the same time in a pre-determined relationship. If the head isn't right for the flute, it's extremely unlikely that stopper and slide will ever be in the right relationship. A wrongly set stopper gives very unfocussed performance - just what this flute-head combination displayed.
The flute, but with a more normal head
With that experience behind us, the flute was fitted to a McGee flute head and barrel combination. These results were recorded:
Obviously the exact slide extensions needed to produce the pitches above will probably not reflect those of the original. But we can see clearly that the best response comes around the 430 to 435Hz mark, as evidenced by:
How this is determined is the subject of Determining Best Pitch.
The 430-435 pitch range seems perfectly credible. British Low Pitch was 430Hz, with 435Hz the standard on the Continent.
The Third Octave
Once a likely pitch and slide extension for the lower octaves had been obtained, attention could be given to the response of the third octave. This set of fingerings produced the best result:
Illustrating the deviations graphically ...
This is indeed a fabulous result for the period. Notes up to the bottom of the fourth octave could be easily achieved, with one exception. A6 (third octave A) is notoriously hard to control on late conical flutes. It was achievable, but not easily.
So, the Verdict?
In a nutshell, a very fine flute indeed. Clinton has kept the main feature that endears us to the English 8-key - the dark, focussed, powerful tone. And, although his new mechanism is more complex than the collection of keys on an 8-key, it is not greatly so. There remain few interactions between the keys, and so little to cause difficulties in construction and maintenance.
Clinton has also dealt with every one of the failings of the common 8-key flute listed above, and dealt with them successfully. The flute is capable of playing accurately and responsively from low C4 to C7, using the familiar 8-key fingerings, with only a few notes more than 10 cents off ideal pitch. Only one note, A6, proves hard to play and this it has in common with all the later conical designs.
So how did he do it?
Looking first at the power issue, compare these bore dimensions:
We can see that while Boehm, no doubt obeying his German sensibilities, adopted a bore smaller than those in general use in England, Clinton went to the other extreme. Indeed his bore is bigger than any of the other flutes we have so far examined, including the mighty Prattens (not yet invented).
Now let's review the list of weaknesses that Clinton had to overcome, assigning his solutions to the problems:
Other points of interest
|One of the interesting features of this flute - chamfering of the tone holes. This is a technique more commonly associated with oboe makers - the very small holes of the oboe in conjunction with the high sound levels tending to produce unacceptably high levels of noise and intermodulation products at the sharp edges of the tone hole.|
The use of this technique on some but not
all tone holes of this flute suggests some careful
thought and consideration has gone into it.
If you can assist us with any information about this flute, or have queries you'd like us to answer, please contact me!