The tonograph is a device invented by Italian scientist Luca de Samuele Cagnazzi and presented at the Terza riunione degli scienziati italiani, held in Florencein September 1841. , Milan. The original device was donated by its inventor Cagnazzi during the Third meeting of Italian scientists. After then, the instrument went lost, but in 1932 ca., thanks tothe work of a scholar, it was found in a cellar and exhibited at the Museo Galileo, located in Piazza dei Giudici, Florence. The original device is now stored in the Museo Nazionale Scienza e Tecnologia Leonardo da Vinci, Milan. A copy of the device was commissioned by Count Celio Sabini and it's now displayed at the museum Archivio Biblioteca Museo Civico'', located in Altamura.
Working principle
The tonograph is a device consisting of a hollow brass cylindrical section closed at one end and equipped with a hole. The cylinder is in all respects similar to that of the organs. Through bellows, operated through one's feet, the air flows through the cylindrical tube making a sound. Inside the cylinder there is a piston whose position is regulated by a thin rod and, as the position of the piston changes, the length of the cylinder also changes. As the plunger changes, the instrument will generate a different sound. A graduated scale makes it possibile to "measure" the intonation and inflection of human voice, by matching one's voice with the sound made by the device. The scale provided by Cagnazzi, apparently, also related to the harmonic and diatonic scale employed in music. Cagnazzi assumes that there is roughly an inverse proportionality between the length of a closed cylindrical tube and the sound's frequency. Based on this assumption, he came to define the width of the scale and he related the scale of the device with the scale of musics. The device was meant not only to measure, but also to preserve the tones and inflections of human voice. Therefore it also represents, in a broad sense, a device which helps store some kind of information. During the presentation of the device, which took place in 1841 at the Third Meeting of Italian Scientists, during which the device was donated to the department, Professor Giovanni Alessandro Majocchi praised Cagnazzi for his invention, as it provided declamation schools with a way to precisely and successfully store the tone and intensity of human voice. The diatonic and chromatic scales of music didn't have enough notches to accurately represent the tone and intensity of human voice. During the presentation, chemist Giuseppe Gazzeri objected that a mechanical device could never make a sound similar to the human voice, as the material of which the human phonation system is made and the materials of which a mechanical device is made are intrinsically different. '', Altamura. Majeri himself replied to Gazzeri's objection by explaining that sound is described by three factors, namely tone, intensity and timbre. The tone depends on the sound's frequency, the intensity is the "strength" of a sound, while the timbre depends on the material of the "sounding body". Different sounds such as a double bass and a bell may have the same tone and intensity, but they are often perceived as different sounds. The difference is given by the timbre. Since intensity and tone but not timbre are meaningful and employed in acting schools, Gazzocchi's objection, according to Majocchi, is unreasonable "by itself".
Example of use
An example of the use of the tonograph is provided by Cagnazzi himself. The syllables of each word and each sentence of a text to are pronounced slowly enough, so as to imitate the voice with the device. Once the sound of the voice seems closest to the human voice of the syllable, the corresponding value on the scale is transcribed below the syllable. At a lower level, the number of bellows pressures carried out for each word is also added. The "measurement" of the voice requires a lot of diligence and a certain number of attempts before reaching a precise measurement. Luca de Samuele Cagnazzi provides an example of the use of the tonograph based on a notable verse by Ennius : From the example above, it's clear that the purpose of the device is to help store the features of human voice, its tones and music. Cagnazzi himself shaped his experiment based on the information provided by Cicero on how the above verse was pronounced in the classical era. Cagnazzi faces the impossibility of faithfully reconstructing the tones and inflections of the voice that the Ancient Greeks and the Romans used in their survived works. The same inventor, in the first part of his essay Tonografia escogitata made some acute observations on both linguistics and music; he also explained, in the preface, the purpose of his work as well as of his invention:
Previous attempts
According to what reported by its inventor, there had been some previous attempts to faithfully transcribe the tones of acting. Some attempts had been carried out by the Académie des inscriptions et belles-lettres of Paris. Its perpetual secretary Charles Pinot Duclos wrote that abbot Jean-Baptiste Dubos proposed to create a group of experts in the field of music, in order to identify and distinguish fractions of the human voice's diatonic scale. Nevertheless the Académie didn't succeed in the above purpose, since human ears basically can't go beyond a certain level of precision without a proper device. The failure led the Académie to jump to the conclusion that distinguishing between fractions of the diatonic scale was simply impossible, and alternative methods, based on science and mathematics, weren't taken into account. Cagnazzi compared the Académie to the fox in Phaedrus's fable, who said that the grapes were unripe since he couldn't reach it.
