A string stop imitative of the orchestral instrument of the same name, usually of 8' pitch, but occasionally found at 4' or 16'. Grove dates it from around 1700 in Germany. While Wedgwood claims that this stop is rarely found outside the pedal, nearly one third of the examples in Osiris are manual stops. Wedgwood describes it as a full-toned Gamba, and Skinner call it the "broadest and richest of all organ strings". Both wood and metal have been used to construct this stop; Audsley preferred wood, while Skinner seems to have preferred metal. Bonavia-Hunt maintains that the best results are obtained from larger scales voiced on heavy pressure (e.g. 6"). He provides two scales (in metal):
Osiris contains 175 examples of Violoncello, 88 examples of Cello, 62 examples of Violoncelle, and 15 examples of Violincello. Eight of these are at 16' pitch, five are at 4', and the rest are at 8'.