Frédéric Kastner’s Exploding Organ
What do you get when you combine physics, chemistry and music? The answer for one Victorian inventor was a musical instrument called the pyrophone. The clue to how this amazing contraption worked was in the name: pyro, coming from the Greek word for fire, as in pyromaniac, one who cannot resist starting fires.
Georges Eugène Frédéric Kastner was born at Strasbourg in France in 1852 and died in 1882 at the age of thirty. As well as being a physicist and chemist, he was also a musician, being the son of the French composer and musicologist Jean-Georges Kastner. From an early age the young Kastner showed a strong interest in all things mechanical. He was especially interested in the mechanics of railway engines, leading to a fascination for steam, gas and electricity, three motive forces of the Victorian age. Alongside his growing interest in science, he was also tutored in music by his father. Kastner’s interests and studies came together when he filed a patent that combined his knowledge of physics, chemistry and music to create the pyrophone, also known as the gas organ, or sometimes the fire organ.
Frédéric Kastner, inventor of the pyrophone.
In any conventional organ – as well as other types of wind instrument – air is blown across a cylindrical tube or pipe to set a column of air vibrating, which, in turn, creates a musical note. In such cases, the air is introduced to the tube or pipe from an external source. The difference with the pyrophone was that the force that started the air vibrating for notes to be created was internal, in the form of a small explosive burst of flame within a tube or pipe.
Musical flames
This highly unusual form of organ was based on a known aspect of physics that recognised the fact that when a flame crosses a glass tube under a certain pressure, it produces a sound akin to a musical note. The theory of combining light with sound in this way was already established before Kastner came onto the scene, with proposals for chandeliers and candelabras that incorporated what were known as singing flames.
In applying this theory to the development of a musical instrument, Kastner, in a patent filed on Christmas Eve 1874, stated:
It is well known that if a flame of hydrogen gas be introduced within a glass or other tube, and if it be so placed as to be capable of vibrating, there is formed around this flame – that is to say, upon the whole of its enveloping surface – an atmosphere of hydrogen gas, which, in uniting with the oxygen in the air of the tube, burns in small portions, each composed of two parts of hydrogen to one of oxygen, the combustion of this mixture of gases producing a series of slight explosions or detonations.
If such a gaseous mixture, exploding in small portions at a time, be introduced at a point about one-third of the length of the tube from the bottom, and if the number of these detonations be equal to the number of vibrations necessary to produce a sound in the tube, all the acoustic conditions requisite to produce a musical tone are fulfilled.
This sound may be caused to cease either, first, by increasing or reducing the height of the flame, and consequently increasing or diminishing its enveloping surface, so as to make the number of detonations no longer correspond with the number of vibrations necessary to produce a musical sound in the tube, or, secondly, by placing the flame at such a height in the tube as to prevent the vibration of the enveloping film.
The mechanism that allowed two flames to unite or diverge to produce a musical note.
Kastner added to this theory with the discovery that two flames introduced into a tube, one third of the way along its length, remained silent when they burned together, but if they were made to separate, the resulting vibrations in the air within the tube produced a musical note.
Taking this thinking a step further, and in order to turn this sound-making device into a musical instrument, Kastner proposed a series of tubes of varying lengths, with holes set at different distances from the top. When a hole was uncovered, the flames burnt together and were silent. When the hole was covered, the flames separated and produced their sound. The sounds emitted also changed in tone according to the distance between the flames and the holes. Thus, by controlling the covering and uncovering of the holes by means of a series of keys on an organ-like keyboard, a musical scale could be produced.
The pyrophone, as illustrated in Popular Science Monthly, August 1875.
The sound of the pyrophone
All of this is a fairly simplified explanation of how the pyrophone worked. The notes and the harmonics produced were also reliant on the size of the tubes and the intensity of the flames. It was suggested that tubes could also be made with a series of holes to be covered and uncovered as needed, in much the same way as holes are covered and uncovered in a wind instrument such as a clarinet or flute. Describing the sound produced by the pyrophone, in 1875, a correspondent in Popular Science Monthly wrote:
The sound of the Pyrophone may truly be said to resemble the sound of a human voice, and the sound of the Aeolian harp [a device in which the wind blowing through strings in a box produced an ethereal sound]; at the same time sweet, powerful, full of taste, and brilliant; with much roundness, accuracy, and fullness; like a human and impassioned whisper, as an echo of the inward vibrations of the soul, something mysterious and indefinable; besides, in general, possessing a character of melancholy, which seems characteristic of all natural harmonies.
Fuel sources to produce the flames in the pyrophone varied. In describing his device, Kastner spoke about the use of hydrogen, but pyrophones were also made to run on propane and even petrol.
Surprisingly perhaps, the reaction to Kastner’s instrument was mostly enthusiastic. The eminent nineteenth-century German composer and conductor Wendelin Wessheimer was an enthusiastic proponent of the pyrophone, whilst many scientific journals of the day sung its praises. L’Année Scientifique and Le Journal Officiel de l’Exposition de Vienne declared that the instrument was ‘one of the most original instruments that science has given to instrumental music’ and that it could ‘produce sounds unknown till the present time, imitating the human voice, but with strange and beautiful tones, capable of producing in religious music the most wonderful effects’.
Kastner’s own pyrophone.
Rather more humorously, the British Review advocated that the pyrophone might be especially valuable in winter as a means of not only producing music, but also for warming small apartments, and it was suggested that perhaps an economical stove may be added to the instrument for culinary purposes.
Other unusual instruments
Whilst the pyrophone must have been one of the most unusual music making instruments of the age, it was not alone in its weirdness. Xylophones, for example, which had been around for many years, began to come to the attention of musical audiences, although they were played in a vertical upright position, unlike the modern equivalents in which the metal plates that produce the notes when struck are laid out horizontally.
The Aeolia harp was a Victorian update on the Aeolian harp, which dates back to the Ancient Greeks. In the original version, wind blowing through between seven and twenty-one strings contained in a box produced the sound. But, recognising that it was easy for the strings to go out of tune, the Victorians came up with the Aeolia, in which eighty metallic reeds were divided into four groups of twenty harmonic chords. These stood in a box that rotated on a stand in a breeze. The chords were played one after the other as the box rotated and from whichever way the wind was blowing. Their sound was directed into another tube that combined the harmonies.
Nineteenth-century musician Honoré Baudre built a geological piano, whose sound relied on the already known fact that when certain flints are struck together, they produced a musical note. With this in mind, Baudre spent about thirty years travelling the world in search of enough flints to make up several musical scales when struck. According to the pitch of each, the flints were suspended on wires from a metal frame above a soundboard. They were struck by other flints held in the hands to produce the tune.
A similar theory was applied to other rocks and stones that produced various pitches as they were struck. Although the theory had been around for a few centuries, it was in the Victorian era that stonemason Joseph Richardson spent thirteen years collecting enough stones in the Lake District to make his version of the instrument, called a lithophone. Along with his sons, Richardson toured the north of England to give concerts, with a tour that culminated in 1848 with an invitation to perform for Queen Victoria at Buckingham Palace.