A single-ram baler is a baling machine that contains one cylinder. After the alfalfa has dried, a tractor pulling a baler collects the hay into bales. Closed door baler&colon; This baler bales clear plastic film. The back of the baler swings open, and the bale is discharged. Allis Chalmers also built many small square baler models. The continuous hay baler arrived in 1914. The first CLAAS straw baler was produced in 1931. These often used air cooled gasoline engines mounted on the baler for power. PAGASA installed its first Doppler weather radar station in Baler, Aurora and another in Baguio. The "Comedia de Baler" of Aurora mounted its first production in 1927. Edgardo Angara was born in Baler, Aurora. The Caraballos ("Caraballo de Baler") start where the Sierra Madre and the Cordilleras meet. At that time a system of communication between Manila and Baler was almost non-existent. Salcedo reportedly visited the towns of Casiguran, Baler and Infanta. The most common type of baler in industrialized countries today is the round baler.