When Audubon first came to the United States, he brought with him all his drawings of French birds, and a few pieces which may belong to this early period have been described.[154] Done in a combination of crayon and water color, they represent a European Magpie, a Coot and a Green Woodpecker, the latter especially, which bore the number "96," showing evidence of care and skill. The year passed at "Mill Grove" was not particularly fruitful, but during the Couëron visit which followed in 1805 and 1806, Audubon said that he made drawings of "about two hundred species of birds," all of which he brought to America and gave to his Lucy. After finally reaching this country in the latter year, these studies were continued, with an alacrity that seldom failed, until 1822, when he began to revise much of his earlier work, substituting water colors more completely for pastels, pencil and crayon point. In writing to Bachman in 1836, Audubon thus referred to the work of his apprenticeship: "Some of my early drawings of European birds are still in our possession, but many have been given away, and the greatest number were destroyed, not by the rats that gnawed my collection of the 'Birds of America,' but by the great fire."[155] When the naturalist was in Philadelphia in 1824, in search of a publisher and sadly in need of funds, he made the acquaintance of Edward Harris,[156] who looked at the drawings he had for sale and said at once that he would take them all and at Audubon's own prices. Upon his leaving that city, this generous friend, we are told, pressed a $100 bill in his hand, saying: "Mr. Audubon, accept this from me; men like you ought not to want for money." "I could only express my gratitude," continues the naturalist, "by insisting on his receiving the drawings of all my French birds." The worthy Harris cherished this large series of Audubon's early studies and added to it many specimens of his later work. The entire collection remained in his family unbroken and unimpaired until 1892.[157]