This instrument, which has always been known by this name, played a less important role in clockmaking than in watch manufacturing and was therefore used in only a handful of good workshops. A point is marked on the bottom plate and a hole is then bored with the same diameter as the pivot of the shaft to be planted. Once this job is complete, the clock frame is placed on the plate of the planting tool by resting the upper spindle in the hole that has just been bored. The lower spindle then knocks a small hole into the opposite plate to determine if the instrument is accurate, the point exactly opposite the hole of the other pivot of the wheels and pinions. Abraham-Louis Perrelet (1729-1826) has been credited with this invention.