parallel to the work surface 22 the pin 70 is preferably smooth and extends a distance from the base 50 approximately equal to that of the width of the slide block 12 as viewed in fig5 the pin 72 is threaded to receive a wing nut 74 to releasably secure the slide block in position the jig 10 is supported on the base 50 by slidably mounting the slide block 12 on the pins 70 and 72 with the pins extending through the slot 34 when so positioned the slide block 12 lies adjacent the base 50 and is free to slide along a linear path toward and away from the fence 24 preferably the pins 70 and 72 are closely received within the slot 34 to prevent cocking or canting of the slide block 12 from the horizontal the slide block 12 and consequently the jig 10 can be locked in a desired position by tightening the wing nut 74 on the pin 72 the inoperative position of the jig 10 is illustrated in fig3 see also fig5 7 in this position both the link 16 and the registration block 14 hang downwardly from the slide block 12 consequently all portions of the jig 10 are located below the work surface 22 of the saw 10 this permits the work surface to be freely used in a conventional manner without the jigs 10 interfering with any workpiece positioned on the work surface or extending from the work surface in a direction coplanar therewith the operative position of.