There are several reasons why "Buildings on Paper: Rhode Island Architectural Drawings, 1825-1945" has a far more general appeal than the title suggests.

One is, of course, Newport, the fabulous vacationland for the wealthy, a veritable museum of late-19th-century American architecture at its most presumptuous, and in some ways its most skilled level of achievement. The plutocrats who summered there naturally hired the best architects in the East to build their mansions, and more than a third of the drawings in the show are devoted to those "white elephants," as Henry James called them, so "queer and conscious and lumpish."

Even without Newport, the smallest state contributed more than its share to the story of distinguished American building in the 120 years covered by the show. This would be even truer were the exhibition to extend back in time to the colonial and federal periods; but, alas, the amateur architects of that earlier time worked with only the most rudimentary sort of preliminary drawings, so we start here with elevations for several notable Greek Revival buildings and continue through the 19th-century parade of styles up to the beginnings of modern architecture.

The most recent building represented in the survey, now showing at the Octagon, is the elegant 37-room mansion on Fishers Island designed in the late 1930s by Richard Neutra for the John Nicholas Brown family. The drawings for this house, a masterpiece of modernism with its open, split-level plan and its sleek fac,ade of ribbon windows and silver-gray painted wood, will be of more than usual interest to many Washingtonians because it was the boyhood summer home of J. Carter Brown, director of the National Gallery of Art.

Not only does this experience explain something about Brown's taste -- "It amused me to realize that I was one of the few people of my generation to grow up in an International Style environment," he remarked the other day -- it also helps to explain the justifiable pride he takes in the key role he played in the design and construction of the gallery's East Building, and the obvious relish with which he approaches his role as chairman of the Fine Arts Commission.

Enthusiasm for architectural excellence ranks high in the patrician tradition of the Brown family, and their splendid commissions make up a major leitmotif of the exhibition. (This accounts for the inclusion of the Neutra house, even though Fishers Island, located between Rhode Island and Long Island, actually belongs to New York state.) Here, again, the tale would be even more telling if it went back further in time, for Joseph Brown (the brother of J. Carter Brown's great-great-grandfather) was one of the preeminent architects in 18th-century Providence.

Even so, the list of Brown family buildings in the show is distinguished. It starts chronologically with an elevation for a massive stone carriage house designed for John Carter Brown in 1853 by Thomas Alexander Tefft, a talented, eclectic Providence architect, and culminates with two especially impressive buildings.

The first is a perspective drawing by the Boston firm of Shepley, Rutan and Coolidge of the John Carter Brown Library at Brown University (1898-1904), an incisive neoclassical monument. The second is a beautiful rendering of the chapel for St. George's School in Middletown, R.I. (1920-28), by Ralph Adams Cram. This building, commissioned by the young John Nicholas Brown for his prep school, is one of the best examples anywhere of the strong massing and textural niceties of the "College Gothic" style popular in the 1920s.

Even when not directly associated with a commission, the Brown name crops up. One of the earliest buildings in the show, and also one of the more impressive of the public structures in it, is the Providence Arcade, an enclosed mall in the Greek Revival style designed in the late 1820s by Russell Warren and James Bucklin of Providence. John Nicholas Brown was influential in saving this notable building when it was threatened with demolition in 1944. In 1977 the landmark was handsomely restored, and today it is a showcase in the revitalization of downtown Providence.

The exhibition does not provide much evidence of the vigorous vernacular architecture of mid-19th-century industrial mills that Henry-Russell Hitchcock celebrated in his pace-setting photographic exhibition of Rhode Island architecture in 1939. The simple reason is that in their day no one seemed to rate these buildings very highly. Consequently, drawings for them did not survive.

Public buildings and major commercial structures were more esteemed. The State Prison and County Jail designed by Thomas Alexander Tefft in 1855 is especially interesting as an example of how certain architectural motifs -- in this case the pairs of high, unbroken vertical windows arrayed across a severe neoclassical fac,ade -- become attached to certain building types. Similar windows, called Davisean windows at the time after the the architect A.J. Davis, who first employed them in a design for a lunatic asylum two decades earlier, can still be seen all over 20th-century Washington, most recently in Gyo Obata's design for the D.C. Superior Courthouse.

Tefft also designed the Union Depot in Providence, a brick building in a Romanesque Revival style that demonstrates the strong reaction against the Greek Revival that had set in by mid-century. Hitchcock rated this building, since demolished, very highly. It was, he wrote, "without much question the finest early station in the New World."

The exhibition's strongest suit, however, is residential architecture, and Newport is the star of this story. Besides illustrating architectural history, the Newport drawings trace a fascinating social history as well: the development of American wealth from modest to truly awesome proportions, a sequence, as Hitchcock described it, running "from 'cottage' and 'villa' to 'mansion,' from 'mansion' to 'manor house' and 'chateau,' and finally in the last burst of the Nineties, from 'chateau' to 'palace.' "

Newport was a popular resort in 1839, when George Noble Jones commissioned Richard Upjohn to design a summer cottage on a dirt lane running south from Newport, and a cottage, in Upjohn's popular rural Gothic style, is precisely what he got. By the time Stanford White was commissioned to add on to the house in 1880, the dirt lane had become Bellvue Avenue and the cottage was considered an "estate." Like most of its prepossessing neighbors, it was given a name: "Kingscote."

Cornelius Vanderbilt called his house The Breakers. Designed in 1895 by Richard Morris Hunt, who "knew how to house the Vanderbilts at a period when," as Hitchcock noted, "they lived, in the minds of the public, like a new royal dynasty," The Breakers is almost stupefying in its grandeur.

The exhibition, organized by Brown University's Bell Gallery, the Rhode Island Historical Society and the Museum of Art at the Rhode Island School of Design, was researched by architectural historians William H. Jordy and Christopher Monkhouse, who also wrote the impressive catalogue. It continues through Jan. 3 at the Octagon, 1799 New York Ave. NW.