CHAPTER XIII

MARCUS A. ROOT. _The Camera and the Pencil_; or the Heliographic Art, its theory and practice. Philadelphia, 1864.

_Pennsylvania Arts and Sciences._ A quarterly published by the Pennsylvania Arts and Sciences Society. Vol. 2, p. 25. Philadelphia, 1937.

RICHARD BUCKLEY LITCHFIELD. _Tom Wedgwood--The First Photographer._ London, 1903.

GEORGES POTONNIEE. _Histoire de la Découverte de la Photographie._

Paris, 1925.

_The History of the Discovery of Photography._ Translated from the French by Edward Epstean. New York, 1936.

LOUIS JACQUES MANDE DAGUERRE. _Historique et Description des Procédés du Daguerréotype et du Diorma._ Paris, 1839.

CHARLES LOUIS CHEVALIER. _Guide de Photographie._

Paris, 1854.

VICTOR FOUQUE. _The Truth Concerning the Invention of Photography._

Nicéphore Niepce; his life, letters and works. Translated by Edward Epstean. New York: Tennant & Ward, 1935.

_La Vérité sur l’invention de la Photographie._ Nicéphore Niepce, sa vie, ses essais, ses travaux, d’après sa correspondance et autres documents inedita. Paris, 1867.

HENRY RENNO HEYL. “A Contribution to the History of the Art of Photographing Living Subjects in Motion and Reproducing the Natural Movements by the Lantern,” _Journal._ The Franklin Institute. Vol. CXV, p. 310. Philadelphia, 1898.