In 1848, a man named Orson Squire Fowler ignited a homebuilding fad when he dreamed up a  bold new home design, one that might be cheaper, more efficient and even make you happier. 

Inventory of Octagonal Houses in RI - One’s I’ve found to still be there:

• Lemuel C Richmond Octagon House, 41 High Street, Bristol
• Cranston (Battey) Octagon House, 80 Phenix Avenue. The only surviving of 3 once in Cranston. Built around 1854. Today there are four apartments in the building
• East Providence Octagon House, 21 Sunnyside Avenue. Built around 1900 as a bandstand for the short-lived Boyden Heights Amusement Park, and converted to a private residence by 1916.
• Providence, 36 Crescent Street. Eliza H. Dix House, built 1855. 
• Providence, 63 Elmwood Ave. Built 1857 for Silas M. Field, jeweler. Is now a 4 family residence. 
• Providence, 669 Public Street. Now a 4 family residence. 
• Providence, 76 Harrison Street. Modern house. 
• Warwick, 25 South Fair Street, Pawtuxet Village. Built in the 1830s?  
• Albert S. Potter House, 4 Carolina Main Street, Carolina. 
• Riverside, 163 Halleck Avenue. Custom built in 1990. 
• Smithfield, J. S. Sweet Octagon House. Built 1865. 108 Farnum Pike. Need to check this one. 
• Olneyville Octagon House, built in 1988

Houses that appear to have been torn down:

• Bristol Octagon House, Wood Street. No longer there. 
• Central Falls Octagon House, built around 1877 - don’t think it’s still there
• Cranston Ezra Read Octagon House, on Pontiac Avenue. Demolished in the 1970s.
• Cranston Octagon House on Wayland Avenue, on a 1882 map but gone by 1895
• Johnston Octagon House. Built before 1880, located at 745 Hartford Ave near Killingly St. Demolished in the 1960s. 
• Pawtucket Octagon House, located at 42 Park Place. Built in 1856, demolished in the 1950s. 
• Providence, Gano Street. 1906 newspaper article references it. Gone now. Possibly meant another one a street over on Ives. 
• Providence, 343 Williams Street. No longer there. Built pre 1875. Check this one again.
• Providence, Stewart Street. No longer there. 
• Providence, 241 Ives Street. Razed in the 1980s. 
• Providence, Locust Street. No longer there. 
• Providence, 307 Knight Street. Built 1855. Thought to be the earliest octagon house built in the city. Built by Benjamin Merril Hubbard. Went looking for it, but couldn’t find it. Likely gone. 
• Woonsocket, Sabin Pond House. Built 1849. At 315 Grove Street. Gabled Octagon House, very interesting looking. Demolished in the mid 1980s. 
• Woonsocket, 21 (?) Fountain Street. No longer there. 
• South Kingstown, no longer there. 
• Block Island?
• Prudence Island - Not sure of the address!

Episode Source Material

• Albert S. Potter Octagon House - Wikipedia
• The Octagon House Inventory Book
• Octagonal pegs in a square landscape
• 76 Harrison Street, Unit#76, Providence, RI 02909 | MLS #1176582 | Lila Delman
• 163 Halleck Avenue, East Providence, RI 02915 | Compass
• Waltham Watch Company - Wikipedia
• Orson Fowler, the Phrenologist Who Started the Craze for Octagon Houses - New England Historical Society
• The Octagon Houses of Orson Fowler | Amusing Planet
• Phrenology | Thompson | Encyclopedia of the History of Science
• Phrenology in Victorian America (U.S. National Park Service)
• Phrenology – Library News
• Facing a Bumpy History | Smithsonian
• The Fowler Brothers
• The abolitionist, vegetarian, octagon-obsessed utopia that never was | by Meagan Day | Timeline | Medium
• An Eccentric Victorian, His Book and the Giant Pink Pastry of a House He Inspired
• Orson Squire Fowler - Wikipedia. 
• American Phrenological Journal and Miscellany, Volume 11
• When Heads Were Headlines
• Orson Squire Fowler: Phrenology and Octagon Houses 1809-1887 by John H. Martin
• History of watches - Wikipedia
• Battle of the Giant Watchmakers - Business History
• Carolina: Old mill town now a scenic gem