Standard Oil tycoon Charles Pratt had eight children and a strong dynastic streak.  He famously bought 1100 acres of land in Glen Cove, New York to create a compound for his family, giving each child a share of the property.  Ever the efficient businessman, he consolidated estate operations for the various family houses into one compound, called the Pratt Oval, with a central administration building and stable and service facilities for each property.  
 The Pratt Oval, the administrative and service buildings for the Pratt family compound at Glen Cove
Although Pratt died soon after creating the estate, his children embarked on major building sprees, building five famous mansions at Glen Cove, among the most admired houses of their time, using architectural firms such as James Brite, Delano and Aldrich, Walker & Gillette, and Charles Adams Platt.  In turn their children built more houses on the family property, until Depression and World War II took their tolls.  Most of the Pratt houses are today public or semi-public facilities, and the Pratt Oval is just a memory.
But wait—that accounts for the six Pratt sons and one sister, but there was a sixth Pratt child unaccounted for in Glen Cove.  What happened to her?  Where did she live?
In New England of course, almost in the Dilettante’s back yard.   Helen Pratt married Ernest Blaney Dane, a wealthy investor and president of the Brookline Savings & Trust Company, and unlike her siblings who had their beachheads on Long Island and Park Avenue, she lived in Brookline, with a summer home in Seal Harbor, Maine, where also lived the son of her father’s old business partner, John D. Rockefeller.  The E.B. Danes houses were perhaps not as architecturally distinguished as those of her brothers, but they were, nevertheless, impressive by most standards.
‘Roughwood’, as originally built 1889-91 for William Cox
Soon after their marriage, the Danes bought the Cox estate, Roughwood, on Heath St. in Brookline.  It was a very large chateauesque shingle and stone house designed a few years earlier by Andrews, Jacques, & Rantoul.  One of the assistants on the project was a young MIT graduate named Charles Sumner Greene, who would soon move to California with his brother, where they became famous as the firm of Green & Greene.  
 Roughwood’ as it appeared after enlargement by the Danes in the early 1900’s
 The music room wing added by the Danes
After purchasing the estate, the Danes made many improvements, adding an Elizabethan Music Room wing, and an enormous crystal palace style palm house at the other end of the mansion.  
 The garage at ‘Roughwood’.  The true scale of the building is not apparent in this photo.
Early devotees of motoring, they built a large garage, capable of holding nine cars, with a lower level carwash and machine shop, and chauffeurs quarters above.  This garage was published often in its day as a model of modern efficiency.
 The Dane yacht ‘Vanda’ at its launch at Bath Ironworks
E.B. Dane was a devoted yachtsman, and in the summers they went to Seal Harbor on Mt. Desert Island in Maine.  In 1909, they purchased Glengariff on Dodge’s point, a roomy shingled cottage designed by Long Island architect Isaac Green only a dozen years earlier, and demolished it.   

 ‘Glengariff’, Ernest and Helen Pratt Dane’s summer home at Seal Harbor
 In 1911 work was completed on a new and much larger stone and shingled cottage designed by F.L. Whitcomb of Boston, also called Glengariff.  V-shaped, the house dominated the end of the point. The new Glengariff was 40 feet deep and stretched 244 feet from end to end.  Offshore were anchored Mr. Dane’s successively larger yachts, culminating in the 240 foot Vanda, commissioned from Bath Iron Works in 1928.
 Two vintage views of the gardens at Glengariff

A dedicated plantswoman, Helen Dane first had I. Howland Jones of Andrews Jacques & Rantoul lay out terraced formal and informal gardens among the ledges on the rocky steep property—nature tamed by money.  Later, Beatrix Farrand, who maintained an office on her estate at Bar Harbor, was brought in to make changes and improvements, and by 1933, when the Garden Club of America visited Mt. Desert Island, the Dane garden was one of the highlights of their tour.  
 The Dane’s home farm at Seal Harbor
Lacking the Pratt Oval, the Danes purchased land half a mile from the main house for a small gentleman’s farm whose barns, gardens and greenhouses supplied the estate with food and flowers and necessary services. 
 ‘Roughwood’ as it appears today, as the main building of Pine Manor College.  The parking lot to the right is the approximate site of the palm house wing
The Dane estates weathered the great Depression, but by WWII, things were drawing to a close.  The Vanda was requistioned for duty in the war.  The Brookline estate was left in favor of a gentleman’s farm in New Hampshire, where Mr. Dane died in 1942.  The Brookline estate became a private school, and later Pine Manor college.  John D. Rockefeller Jr., in whose view shed Glengariff stood, bought the house for a song in 1946 and had it demolished (His son David later built a house on the property).  The Seal Harbor farm was later used as a riding stable connected to Acadia National Park.
The Pratt estates on Long Island are extensively documented on the blog ‘Old Long Island’, and those posts can be accessed by clicking HERE.
For a fascinating 1919 Country Life article about the Pratt estates at Glen Cove, click HERE
For a New York Times ‘Streetscapes’ article about the Pratt town houses, click HERE

And as always, click on any picture in this blog to enlarge for more detail.