Abstract: A learning device for stringed musical instruments having a fingerboard with one or more frets, comprising a top surface having printed thereon a series of musical notes indicators and one or more perforations having dimensions and positioning corresponding to the one or more frets an a bottom surface configured to fasten the learning device to the fingerboard of the stringed musical instrument. The learning device is configured such that when it is fastened on the fingerboard below the strings of the stringed musical instrument the one or more frets protrude from the one or more perforations and the musical notes indicators are positioned at corresponding musical notes positions on the fingerboard.

Abstract: The invention relates to an improvement with apparatus for the decantation treatment of liquid containing therein suspended material and comprising a sludge bed contained within a first network of plates or tubes. This improvement is characterized by the fact that a second network of parallel plates inclined to the horizontal at an angle from 40 degrees to 80 degrees (especially 60 degrees) is positioned within the sedimentation zone, the distance between adjoining plates of said second network being much smaller than the one between adjoining plates of the first network.

Abstract: A manually operated wire or cable bending apparatus comprising a support assembly for supporting a forming die at one end thereof. A drum assembly comprising a pair of spaced apart interconnected weighted members is mounted on the support assembly, one such weighted member provided with graduations thereon from 0.degree. to 360.degree. on one end face thereof, whereas the other said weighted member having a means for swivelly securing a measuring tape which is adjustably mounted on said support assembly. The forming die comprises a forming block pivotally mounted on a rotatable handle, the forming block cooperating with a fixed grooved forming die to bend a wire or cable positioned between the said forming block and said grooved forming a die when a handle to which the said forming block is pivotally mounted thereon is rotated counterclockwise.