According to Keister:
William F. Foster made his rather large fortune by manufacturing a rather small product: fasteners. He also made kid gloves. His final resting place was the subject of a lot of media attention when it was constructed in 1895. The canopied granite structure, which has a cruciform footprint, was designed by architect John Wooley, who had offices at 111 Fifth Avenue. Wooley’s design broke the mausoleum mold since it did not have walls and a door. Despite using massive blocks of granite, the tomb has a much lighter feel, thanks to its open air construction. The base of the tomb is a single 42 x 24 foot 40 ton slab of granite, which was one of the largest ever quarried in Westerly, Rhode Island, an early center for granite quarrying in the United States. Under the slab are catacombs, which have space for eight permanent residents. Centermost on the massive slab is a double sarcophagus containing the mortal remains of William F. Foster. Sixteen Tuscan columns frame the stone ensemble. In all over 1,100 tons of granite were used in the construction of the 52-foot-high tomb.
The structure takes the form of a canopy tomb rather than a mausoleum, although its sheer size puts it in a classification usually reserved for mausoleums. In the simplest sense, canopy tombs are tent-like structures that shelter a sarcophagus. These structures, usually composed of columns or pillars supporting a dome, are open-air affairs, and unlike mausoleums, they have no doors restricting entry. Copies may be seen in a variety of ancient architecture. They didn’t become part of the European and American architectural repertory until the eighteenth century, when architects began using them for garden pavilions. The decorative potential of these canopied pavilions and kiosks were soon exploited by designers of funerary monuments. The are often seen hovering of a grave or small monument, or sheltering a sarcophagus. The Foster Tomb is among the largest canopy tombs in the world.
When I saw this tomb I recalled from my days living in Geneva another similar, although more gothic in style, canopy tomb: The Brunswick Monument (see below) – itself a copy of the Scaliger Tombs in Verona, Italy. This tomb was built in 1879 for Charles II, Duke of Brunswick (1804 – 1873). It stands right next to Lake Geneva near to the Mont Blanc bridge (Pont de Mont Blanc). The story that is told in Geneva is that he left his fortune to the City of Geneva on the condition that he be entombed facing the lake. The story went on to say (and I don’t know if this part can be verified) that the the fortune turned out to be less than anticipated so they placed him facing away from the lake rather than towards it. See: Lake Geneva 2004 – View from my hotel room for the kind of view that the Duke would have wanted. The monument is right next to the hotel I stayed in).