Richard Carte’s
Comments regarding the 1847 Boehm Patent

We continue the series of articles examining statements made by English flute designer and maker Richard Carte.  Carte comments on two issues in Boehm's 1847 patent which invite our attention.


The main thrust of Carte’s 1851 “Sketch of the Successive Improvements in the Flute”, which was to stand as his major written contribution to the historical record with respect to flute development, was the promotion of his own newly-developed flute designs.  These designs utilized the 1847 Patent taken out by John Mitchell Rose of the firm Rudall & Rose on behalf of Theobald Boehm.  The Patent was fairly general in its application, but incorporated the metal cylinder-bored version of the Boehm flute which had been realized by Boehm in 1847 following a period of intensive study and experimentation. 

Carte very much appreciated the tonality and intonation made possible by the Boehm Patent as applied to the flute, but was firmly convinced that the associated fingering complexities presented an insurmountable sales barrier.  His own designs reverted in large part to the old fingering of the 8-key flute with a substantial number of additional facilities thrown in. His “Sketch” was largely devoted to a consideration of the fingering difficulties of the Boehm instrument and to the promotion of what he claimed as the superior attributes of his own system allied to the Boehm Patent.

Issue No 1 - the Extent of the Patent

In the “Sketch”, Carte had occasion to base his side of an argument directly upon the content of the 1847 Patent.  In doing so, he  made the following statement:

 “Boehm's (1847) patent relates only to the Flute, and does not extend to the material of which it is formed” [our emphasis]

This must surely stand as one of the most inexplicable statements ever made in relation to the flute by a person as closely informed as Carte undoubtedly was, or should have been.  If we refer to the actual Patent specification (still available at a very reasonable charge from the Patent Office in London), we find the following wording:

The invention consists in: 1) Constructing flutes of all descriptions, clarionets and other similar wind instruments, of metal instead of wood or other materials; by which such instruments are more easily kept in tune , and are less liable to crack from heat.”  [our emphasis]

The above paragraph clearly does not relate “only to the flute” and most definitely doesextend to the material of which it is formed”!  Carte has made two obvious mistakes in one sentence.  He had been closely familiar with the 1847 Boehm flute since its introduction – indeed, he had openly utilized the Patent himself in the development of his own 1851 Patent flutes which formed the main subject of his “Sketch”, to the extent that his 1851 Patent flutes were specifically marked as incorporating Boehm’s patent as well as Carte’s own. It thus appears to be simply inconceivable that he could not have known the true state of affairs regarding the contents of the patent. It may be fascinating to speculate upon the reasons for Carte’s extraordinary lapse, but the present authors will leave that to others.

It is of the greatest interest to note that until now, no-one appears to have noticed or commented upon Carte’s unmistakable and readily demonstrable gaffe.  Given the readiness of mid-nineteenth century commentators to seize upon each others’ errors and attempt to make capital of them, this is perhaps surprising.  The best explanation that we can offer is the notion that perhaps people simply didn’t bother to read the “fine print”, which in this case would have required going to the trouble of obtaining a copy of the actual Patent specification.  There appear to be other examples of this lack of attention to the details.

Issue No 2 - the Parabola

One of the key features of Boehm’s Patent as it applied to the flute was the design of the head-joint, which is described in the Patent specifications as being “conical, or rather in the form of a parabola”.  This feature was a major selling point in Carte’s marketing strategy for his own 1851 Patent flutes, which utilized this technology.  Carte used the term “parabola” to characterize this component of the flutes on the new bore, both in his “Sketch” and in his promotional materials.  However, it is beyond dispute that he was not strictly correct in likening the form of this joint to a parabola, and it also appears highly improbable that he could have been unaware of this.

In his long-unpublished 1847 “Essay”, to which Carte undoubtedly had access through his close relationship with George Rudall, Boehm himself stated merely that the basic form of his head joint “approached the parabola” and terminated in a “hemisphere”.  The combined form in no way resembles a parabola, as Boehm clearly recognized given his qualified use of the term “parabola” and his use of the two distinct forms in describing the overall configuration. Furthermore, in the wording of the British Patent taken out on Boehm’s behalf by John Mitchell Rose, the form of the joint is described as “conical, or rather in the form of a parabola”, as noted earlier. There is also a cylindrical portion at the tuning slide end of the head joint. So, as described by himself, Boehm’s head-joint was in fact a combination of hemisphere, near-parabola and cylinder.  Taken as a whole, it cannot truly be considered to be a parabola, or anything like it.  The following sketch should help to make this clear:

The blue trace in the graph above shows the dimensions of one of Boehm’s own heads, No 21, in the Dayton C Miller collection in Washington.  The vertical section at X = 0 is the stopper face, the open end at the right is where the head plugs into the body. 

The orange trace shows a classic parabola (of the form y2 = kx) of the same diameter at the open end, and the same overall length.  It looks a little odd here because the horizontal and vertical dimensions are different in the opposite way to what we are familiar with – the parabolic satellite dishes and lighthouse lamp reflectors we know have large diameters and small depths, while this has a small diameter and considerable depth. 

Clearly the two traces have little in common, indeed the head is closer to being a cylinder than a parabola.  It can be seen however, that if the length of the orange parabola curve were to be greatly magnified, but the right hand ends kept in the same place (i.e., the left hand centre of the parabola is now 100 screens off to our left), the orange and blue traces would largely coincide.  This is presumably what Boehm meant when he talked of the bore of the head “approaching” the form of the parabola – he was referring to a specific portion of a parabolic curve, not the curve as a whole.  It is extremely difficult to believe that, as a player and designer of flutes using this head-joint, Carte would not have been aware of this. 

(At this point, an extremely interesting side matter presents itself – Boehm’s mention of his head-joint design terminating in a hemisphere.   We are not currently aware of an extant Boehm flute that has a hemispherical cavity rather than the usual flat-faced stopper, but the green trace in the graph above would presumably illustrate what it would look like.  It seems to suggest that Boehm might have been aware that the stopper cavity acts indeed as a cavity and not a resonant column, although this is not borne out in his writing.  In any event, Carte himself makes no mention of the hemispherical termination and it certainly would not convert the head taper into a parabola.  Interesting however - if any reader is aware of such a stopper applied to a Boehm flute, we would be grateful for any information.)

However, even this question of the stopper does not alter the fact that if we take the whole of Boehm's head-joint into account (the stopper, whether hemispherical or flat, the intervening curved portion and the cylindrical portion approaching the main bore), the form of the head-joint as a whole immediately loses any resemblance whatsoever to a parabola. In that respect, the various historical detractors of the use of the term “parabola” stand on unassailable ground and Carte’s unqualified use of the term to describe the form of the Boehm head joint is undoubtedly not correct.

Compounding the felony

Although the unqualified use of the term “parabola” to describe Boehm’s head joint has been openly criticized in the past, we feel that Carte might have got away with using the term “parabola” as a commercial “label” as long as he clarified the use of the term in the manner set out above, which he did not do.  But even so, this is really an error of little consequence, and if Carte had stopped there we might feel that there would have been little to quibble about – we could set it down to a simple example of commercial “spin” on his part, as others have done before us.  But he did not stop there – in his “Sketch”, for reasons which are unclear, he chose to launch into a pseudo-scientific explanation of the manner in which the “parabola” head joint functioned, as follows: 

"The parabola-head-joint seems to effect that for propagating sound, which the parabolic reflector does for propagating light. The vibrations are concentrated in, and propelled from the one, as the rays of light are concentrated in, and transmitted from the other, both with superior velocity and power."

Well, really ………!!! Scientists from well before Carte's time would have been amazed to find that both the speeds of sound and light, traditionally taken as constants, were capable of enhancement through use of the parabola!  OK, you begrudge, let's ignore the claim about velocity.  But what about power - couldn't the reflective powers of the parabola increase the effective power emanating from the instrument?

Unfortunately, not at this size.  Waves can only be successfully reflected by things at least several times their wavelength, so we'd need a dish some metres across to see substantial gain at flute frequencies.  And in any case, as we have noted earlier, the head-joint as a whole bears very little resemblance to a parabola, a fact of which Carte could hardly have been ignorant. Therefore, the comparison with a parabolic light reflector has no factual or theoretical basis whatsoever, as Carte must surely have been aware unless he was unbelievably ignorant regarding the whole issue.

Indeed, Carte’s own words elsewhere in the “Sketch” confirm that he was in possession of evidence to suggest that the above “explanation” was unfounded.  Commenting on the fact that his new Patent flutes were available either with the Boehm cylinder bore (with "parabolic head") or the Improved Conoidal bore (with cylindrical head) developed by John Mitchell Rose, Carte claimed that the tone of flutes built to his system using Rose’s new conoidal bore was:

so much ………improved that it becomes a matter of opinion whether the wooden flute, with parabola and cylinder, or with this improved conical bore, is now the better”

It would appear that the old cylindrical head gave the much-vaunted “parabola” a good run for its money if this was the case! Indeed, anyone who has ever tried a modern cylinder flute with a cylindrical head will have noticed that it is more powerful than with the Boehm-tapered head.  Tuning suffers though, as does the quality of the notes as, with the cylinder head, the harmonics are badly out of tune.  Again though, a mortal blow to Carte's parabolic propagation claim.

The most basic consideration of Carte’s explanation set out above reveals it to be meaningless mumbo-jumbo, presumably intended to impart a scientific spin to the flutes which Carte was promoting in his “Sketch”. We have noted in our Historical Veracity essay that the motivation for incorrect statements is immaterial when testing such statements for their accuracy – the only point that matters is setting the record straight. 

On the basis of this examination, Carte’s comment regarding the function of the “parabola” head is complete nonsense and also reinforces the view of his unqualified use of the term “parabola” in his sales patter as another misrepresentation. Even if it could somehow be proved that these were honest errors and that Carte truly believed what he wrote (which is undeniably possible), it would then reflect a surprising level of ignorance on Carte’s part and would call both his powers of observation and his fundamental understanding of acoustics into serious question.


Prepared by Adrian Duncan and Terry McGee.  Thanks to the Library of Congress for supplying the data on the representative Boehm headjoint illustrated above.


On to Carte’s Claim to Priority as an English-born Player of the Boehm Flute

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  Created December 2006