IF HARVARD STUDENTS can be considered a fair sampling of the art public, it's going to be a while before artists like Richard Long gain broad acceptance. Long's Installation" in the courtyard of the Fogg Museum received little more than skeptical glances and cursory remarks from students drifting out of Fine Arts 13 last week.

The reaction was predictable--the sculpture consists simply of flat, irregularly shaped pieces of stone arranged in a circle on the floor. Long and others who create so-called environmental art have met misunderstanding and hostility from the press and the public since the movement got underway in the 1960s. The category of environmental art includes such diverse and controversial projects as Christo's "Running Fence," which stretched along miles of the California coastline, and Robert Smithson's full-sized "Spiral Jetty" in the Great Salt Lake in Utah.

Journalists have been quick to criticize the works, suspecting that somehow the artists are playing a big joke on us all. Ironically, the main support for environmental art has come from within the art world itself. Artists creating works which were deliberately too big, too awkward, or too temporary to be bought, sold and exhibited on the gallery/museum scene were offered museum shows and commissions throughout the world. By some feat of ingenuity, the masterminds of the art business managed to make the unmarketable marketable.

Long is a notable case in this art-historical irony, a man who became a professional artist almost in spite of himself. The young Englishman did not start out at the easel, studiously painting still lifes and landscapes. Instead, his art came out of his life, out of his long walks in the wilderness, out of the miles he has traversed in places as diverse as England, Africa and the Arctic. His first works of art were direct factual documentations of his wanderings--maps and photographs carefully recording the trips. Sometimes Long would establish a program; in "164 Stones, 164 Miles" he walked across Ireland, placing a nearby stone on the road at every mile along the way.

Long became interested in the idea of leaving a tangible record of his path on the landscape. He would gather together local materials such as stones, branches and brush, arranging them in circles or lines often reflecting the contour of the terrain. In "England" Long picked flowers out of a field, leaving a green X of plain grass. Long's groupings are all of a temporary nature--patterns in sand that wash away with the tide, clumps of desert grass that will be scattered by the wind. Long's two photographs of man-made structures are significant: Windmill Hill, home of "the first inhabitants of England to make permanent changes in the landscape," and Coalbrookdale, "the birthplace of the Industrial Revolution."

Long's indoor works are a strange contradiction in terms. The pieces are similar to those done outdoors--circles and lines in stone and wood. While the coarse raw materials seem out of place on smooth, polished gallery floors, the simple geometric forms work well in architectural frameworks. In Long's works, nature does not rebel against enclosure; rather, all is calm and ordered. Circles are centered in rooms, and lines of stones parallel the walls. The indoor works have none of the geographic specificity of the outdoor pieces; they can work in any number of interiors. In a rare case, an exhibition at the British Pavilion in 1977, Long created a piece unique to the museum space, a line of stones that travelled in and out of rooms and eventually out the door.

Understanding Long's art is a process of absorption. By nature a reticent and thoughtful man, Long makes little effort to verbalize his intentions in conversation or in writing. He is interested in the relationship between the public and private aspects of art. He sees installations like the one at the Fogg as a way of "making public what I've done in a very private way." One senses the gap in this tenuous communicative linkage--Long's message is not easy to decipher.

Instead, Long's expression creeps into our minds by way of our senses, by contemplation of the subtle calm and simplicity of his method. Long's work is about man's eternal search for order in the chaos around us. He feels impelled to wander in nature, building his own rational and controlled systems from the material around him. The pieces are man-made, yet not artificial. Long is sincerely interested in "the invisibility of art." The phrase is no scrap of artistic rhetoric; it is, rather, the heart of Long's mind. Long is an artist who is, he says, striving "just to reflect the natural state of things."