Architectural Study of Abbey Church of St. Leu d'Esserent

American architect Arnold William Brunner's technical drawing documents the vertical elevations of the Abbey Church of St. Leu d'Esserent in Oise, France. The study presents five cross-sectional profiles rendered in ink with cross-hatching, showing the church's interior spatial relationships and structural geometry. Horizontal guidelines and notational marks indicate measurement systems and construction details. This working drawing exemplifies 19th-century architectural practice, capturing empirical study of Gothic ecclesiastical architecture—a primary source for design education and historical documentation in the Gilded Age.