I'm not sure just when I first came across one of Watteau's red, black and white chalk drawings, but I remember being instantly taken with them. The Metropolitan Museum has Seated Woman, 1716-17, which is both excellent and fairly typical. The Getty has four of Watteau's works in this medium.
This photo of several windmills in Holland is very appealing, no? It's by Corry DeLaan, of Munich, Germany. Note that you can change the background to the photo by clicking on one of the grayscale-squares in the upper left corner of the Photoblink screen.
This etching of the Choir in St Paul's Cathedral, London, strikes me as very fine. It was made in the 17th century by Czech artist Vaclav (Wenceslaus) Hollar. (The zoom feature is essential to a proper appreciation of it.)
The National Gallery of Art has mounted an exhibition called the John Wilmerding Collection: "American Masters from Bingham to Eakins," and has placed a generous selection of works online. The exhibition can be approached in a number of ways --