During William A. Harper's brief life, he focused his artistic pursuits on representations of the landscape around him, from France, where he studied and lived for part of his life, to Mexico, where he died. He portrayed scenes ranging from fields, hillsides and seascapes to built structures such as terraces, patios and staircases. In "Staircase," Harper uses cool tones as well as impasto brushwork and scumbling to delineate sleek steps, aging walls and winding vines. In the foreground of this quiet and unpopulated scene, a thickly painted potted evergreen anchors the bottom of the steps that leads the eye to two small busts on pedestals hidden under a protective awning.

百度翻译： http://fanyi.baidu.com

　Impasto is a technique used in painting, where paint is laid on an area of the surface in very thick layers, usually thick enough that the brush or painting-knife strokes are visible. Paint can also be mixed right on the canvas. When dry, impasto provides texture; the paint appears to be coming out of the canvas.

　The impasto technique serves several purposes. First, it makes the light reflect in a particular way, giving the artist additional control over the play of light in the painting. Second, it can add expressiveness to the painting, with the viewer being able to notice the strength and speed by which the artist applied the paint. Third, impasto can push a piece from a painting to a three-dimensional sculptural rendering. The first objective was originally sought by masters such as Rembrandt, Titian, and Vermeer, to represent folds in clothes or jewels: it was then juxtaposed with a more delicate painting style. Much later, the French Impressionists created pieces covering entire canvases with rich impasto textures. Vincent van Gogh used it frequently for aesthetics and expression. Abstract expressionists such as Hans Hofmann and Willem de Kooning also made extensive use of it, motivated in part by a desire to create paintings which dramatically record the action of painting itself. Still more recently, Frank Auerbach has used such heavy impasto that some of his paintings become nearly three-dimensional.

百度翻译：http://fanyi.baidu.com