Audsley describes this stop as follows: The name to be found in certain important Organs constructed by Walcker, of Ludwigsburg, designating a manual covered stop, of 32 ft pitch. This very grave stop is never carried below tenor C, chiefly on account of the great size of the pipes composing its bottom octave, but also to avoid giving undesirable gravity and dullness to the manual bass. Examples of the Manualuntersatz, 16 ft., under that name, exist in the First Manual division of the Organs in the Cathedrals of Ulm and Vienna. This grave stop has been seldom introduced in English Organs; examples exist in the Greats of the Organs in the Parish Churches of Leeds and Doncaster, labeled Sub-Bourdon, 32 ft. Under the name Contra-Bourdon, 32 ft., Hill has inserted it in the Great of the Organ in the Centennial Hall, Sydney, N.S.W. All these stops commence at tenor C. We have not been able to find a single example in a French Organ. It is worth mentioning, in light of Audsley's final remark, that while 32' stops were not common in classical French organs, they were more likely to appear in the Grand Orgue than the Pèdale. The organ in Saint-Martin, Tours, built in 1761 by LeFèbre, contains both a 32' Montre and a 32' Bourdon in the Grand Orgue.