In the Palms Apartment House for the Palms and Book families, Albert Kahn first experimented with the use of reinforced concrete. His design employs steel reinforced-concrete floors with load-bearing limestone walls. Kahn's brother Julius, who was his chief construction engineer, perfected a precise scientific system for reinforcing concrete. Soon after the Palms was completed, he formed the Trussed Concrete Steel Company and created the famous Kahn System. The U-shaped Palms Building has polygonal turretlike end bays, cast-iron bays, and balustrades. Originally it contained eleven luxury apartments.