On the other hand in 1811 a baby was born in the family of certain organ builder living in a southern French city Montpellier after some years' refuge in Spain. The grand father of this baby, formidable organ builder Jean-Pierre was friends with Dom Bedos, author of the famous treatise : "L'Art du Facteur d'Orgues".
If one talks about the instrument of Jean-Pierre, one must know that his voicing after the tradition of the "Midi" (south France), is much more warm and powerful than that of so called "French classic organ" known to foreign countries. He got married with a girl from Barcelona, Maria Francesca Coll. This marriage destined their children to succeed maternal name added to paternal name after a Spanish custom. One of their children Dominique Cavaille-Coll thus came to be father of our Aristide (1811-1899).

In 1832 he stays in Toulouse to make his study of mathematics. When Rossini came in this city to present the opera "Robert le Diable", Aristide got an extraordinary chance to demonstrate and explain about his recent invention to this famous musician. This instrument named "Poikilorgue (varying organ)" is a kind of Harmonium or Reed Organ which produces a effect of "expression (crescendo, decrescendo etc.)" adopting Free Reeds and a single set of bellows driven by a foot pedal. It has another foot pedal which does not drive bellows but compress and regulate the air of reservoir connected to them. A real Poikilorgue can be seen nowadays in a 
private Harmonium museum in Liestal (near to Basel, Switzerland, CH-4410). 
Surprised with the intelligence and imagination of young Aristide, famous Rossini suggested him strongly to go up to Paris, the capital of France. Thanks to him who was kind enough to write some letters of introduction for the eminent persons in the capital, he got started for Paris in 1833 with his elder brother Vincent and his father Dominique. Three Cavailles settled down in this way at 11 quai Voltaire, Paris VII^e (near to Pont du Carrousel). Encounter with Rossini opened the door to the adventure of Aristide. 

There he presented himself to some important figures such as Cherubini who would be one of the members of the new organ committee for distinguished basilica of St-Denis (north suburb of Paris) to announce the bid only some weeks after the arrival of our three provincials. The chance is always with him. The decision to build a new organ has been waited for 33 years after the dismantling of the old one damaged by the vandalism during the revolution. Aristide hit on the announcement of the bid when he came here all by chance to admire this basilica of prestige in such a way as if the history has been longing for him. With all inventive spirit he made up the estimate for a revolutionary instrument only in several days. The result was there. 

The committee set their heart on this young builder unknown for this moment beside his competitors in first order, which is thanks to his estimate of incontestably great quality (and maybe also to the acquaintance of some members already impressed by his divine spirit). This is the way our symphonic engine has started. 

By 1837 he finished construction of the instrumental part in collaboration with his family. And he was waiting the completion of organ case entrusted to the architect of the time Francois Debret. Setting up the case, however, was delayed toward 1839 by the restoration of the basilica. Paradoxically this delay brought another chance to Aristide faced on a big problem of heavy touch to resolve. 
In the instrument of such a great dimension, he put all the improvements which is radical but reasonable with providential view :

The advantages of this pneumatic device (called Barker lever) attributed firstly to its touch as agreeable (light) as and analogous to that of the mechanical action of a classic organ. 
When one touches a note of a keyboard, a tracker pulls directly the corresponding pallet of the wind chest. The initial resistance which an organist perceives is the air resistance to the pallet which opens against the wind. The touch of the organ with Barker lever, it is given by the intake valve of this device which is much smaller than a real pallet of the wind chest but which opens against the wind as the real pallet does. The air introduced into the pneumatic lever inflates this so as to augment the force enough to open the pallet. This is the principle of Barker lever with which Aristide achieved his opus 1 in 1841.   

The reason why Aristide is regarded as one of the best organ builders can be explained with his intuition to such a good technology as this. His manner is much more radical than his contemporaries but always reasonable.

Bibliography :
- Claude Noisette de Crauzat / "Cavaille-Coll", Ed. Flute de Pan, 1984.
- "L'Orgue, cahiers et memoires, No.48", Association des Amis de l'Orgue, 1992.
- Loic Metrope / "Les Grandes Orgues Historiques de St-Roch", 1994.
- Pierre Pincemaille / "Le Grand Orgue Cavaille-Coll de Basilique de St-Denis (CD)", SOCD 116, 1994.

In the next page (publication in november 1998), I'm going to explain the character of organ music from the "Second Empire Epoch" and the foundation of French Organ School of the 19th century.