which is fastenable to a face 34 of the jaw 14 by means of one or more carriage bolts 36 any number of through extending apertures may be provided in the jaw 14 so as to receive one or more bolts 36 thereby to selectively position the stop member 30 at any desired location along the face 34 fixedly secured to a rearward portion of the u shaped member 32 is a cross extending member 38 having end sections 40 42 which extend outwardly beyond the maximum width of the u shaped member 32 the purpose of this cross extending member 38 will be described subsequently in greater detail the particular positioning of the stop member 30 as shown in fig1 is chosen in those situations where it is desired to have a practice board 26 in substantial parallel alignment with the board holding jaws 12 14 it should be further noted with respect to this first embodiment of the invention that the two supporting carriage bolts 22 24 are positioned on only one side of the upright support 20 thereby to afford ease of attachment of the holding device 10 to the upright support referencing fig3 and 4 of the drawings a modified embodiment of the holding device 10 which is generally designated by the reference numeral 44 will be described this modified embodiment of the invention utilizes a pair of holding members 46 48 which are positionable on.