This is an alto valve trombone in Eb made by Moses Slater, 42 Cortland St., New York.  It has an overall length of 23 inches and a 6 inch diameter bell - silver plated and employing early Perinet valves. It comes in a fitted  coffin case lined with velvet. Slater horns are known for their excellent workmanship and quality and represent the state of the art in 19th century instrument manufacturing. This alto still plays with a clear centered sound over a wide tonal range.