Autograph letter signed, Marcel Pagnol to a physicist [probably Marcel Boll]

Marcel Pagnol (1895-1974), autograph letter signed, Cannes, Hôtel Carlton, n.d. [between 26 April and 10 May 1955], to a physicist [probably Marcel Boll]; in black ink.

2 pages, Quarto (270 x 208 mm).
A delightful letter in which Pagnol, president of the jury of the Cannes Film Festival, relaxes from the screenings by putting to a physicist a problem of thermodynamics concerning the compression of ether.

« Mon cher maître,
Comme d’habitude, je lis le matin quelques pages de thermodynamique, pour changer d’idées, et je ris de notre cher abbé Mariotte, dont la loi ne s’applique qu’au baccalauréat – Loi mère du gaz parfait, qui la suivrait filialement, s’il existait.
Je vous demande encore une fois la solution d’un calcul élémentaire : Soit 1 gramme d’éther à 193°, au dessus de son P.C, sous la pression critique de 35 Kgs.
Combien de Kgm faudra-t-il dépenser pour comprimer cette vapeur sèche à 100 Kgs ? (θ constante)
2° L’éther pur est-il conducteur ? Peut on le chauffer en vase clos, sans air, avec une résistance nue ?
Cela me distraira du Festival, que je préside consciencieusement.
Affectueusement,
Marcel Pagnol
Hôtel Carlton
Cannes. »

One word struck through on the first page, folds from posting.

Pagnol presided over the jury of the eighth Cannes Film Festival, held from 26 April to 10 May 1955. A contemporary report shows the Festival Palace and the Carlton as his two places of work.
At thirty, before Topaze and Marius, he had considered devoting himself to science and had begun a work he intended to call Éléments d’une thermodynamique nouvelle. He later invented water pumps and various machines, building models and prototypes in the workshop he kept in each of his residences.

The problem posed is accurate in its data: the critical point of ether lies at around 194°C and 36 atmospheres. The « abbé Mariotte » is Edme Mariotte (c. 1620-1684), whose law relates the pressure and volume of a gas at constant temperature. The « Kgm » is the kilogram-metre, an old unit of work.