Hippolyte Fizeau was a student of François Arago at the Paris Observatory. His first major contribution in the field of photography, announced to the Académie des Sciences in 1840, was the introduction of gold toning, an improvement in processing which became standard practice from then on. He became interested in the possibility of achieving multiple engraved copies directly from the daguerreotype original and in 1841 presented his preliminary experiments at the Académie. In 1843 he produced a series of daguerreotype views taken from his window in the rue du Cherche-Midi in the Quartier Saint Sulpice and succeeded in achieving an improved direct etching process, examples of which appeared in later parts of Excursions Daguerriennes published by Lerebours in early 1844.