In July 1816, the Company of Encouragement for the National Industry had launched a competition with the purpose of finding calcareous stones (i.e. limestones) in France, which could be used in lithography. The award for this competition was 600 francs. M. de la Chabeaussiere, who had been informed of the competition, told Claude Niépce about it, who then remembered the limestone on which his nephew had engraved his drawings.
Claude immediately asked Nicéphore to send a sample of this stone, and also to find information about its origin and the possibilities of exploiting the quarry where it came from.
Nicéphore wrote to his brother on July 8th, 1816: “As soon as we shall be back to St.Loup, my dear friend, I shall perform the task you ask me to do on behalf of M. de la Chabeaussiere. I shall do it, as you might know, with a double pleasure as it will please you and oblige him. I will join to this letter the little oval stone that Isidore used, and which could be put to use right away for this new type of engraving.”
Following this, Niépce explored the region in search of a limestone quarry.