The scientific observatory of Dr. Jules Janssen was built on the summit of Mont Blanc in the mid-1890s. The mountain infantry of the French army (the Chasseurs Alpins) claimed the summit position on the cover of Le Petit Journal in 1901.
Source: “Les Chasseurs alpins au Mont Blanc,” Le Petit Journal, supplément Illustré, vol. 12, no. 559 (4 Août 1901): 241. General Collection, Beinecke Rare Book and Manuscript Library, Yale University, http://hdl.handle.net/10079/bibid/9351941