When the great folly builders of the 17th and 18th centuries were erecting statement buildings on the high points of their estates, they can little have known how useful they would be to the Board of Ordnance. The ‘Principal Triangulation of Britain’ was a trigonometric survey, begun in the late 18th century, which by determining precise coordinates of significant landmarks would enable highly accurate mapping. The main landmarks used were church spires, but ‘other remarkable objects’ were picked, and in the first decade of the 19th century over 50 towers, temples, obelisks, summer houses and follies made it into this category.
In the 1760s Sir Thomas Wentworth* (1726-1792) of Bretton Hall, near Wakefield, set about landscaping his park. Initially, he employed Richard Woods, a professional landscape designer, but soon decided he could manage just as well on his own. In the 1770s he added to his grand design without recourse to even the most eminent landscaper of the age: Lancelot ‘Capability’ Brown. A second lake would, he told friends, be completed without the help of ‘Capability or any such pretending Rogues’.