| 摘要 |
A method of using an article to facilitate determination of the location of the balance hole necessary to change the side, finger/thumb and top/bottom weights of a bowling ball from known starting weights to desired ending weights, or to determine a set of ending weights necessary to place the center of gravity of the ball at a desired location. The article may also be used to determine the amount of weight to be removed by the balance hole in order to provide the desired ending weights. The article includes a base sheet, having a set of X-Y coordinates and an arcuate scale printed on one surface, and a linear reference line movable with respect to the base sheet about an axcis through the intersection of the X-Y coordinates. Indicia scales adjacent the X and Y coordinates are marked in uniform increments. The arcuate scale intersects the X and Y coordinates at points appreciably spaced from the intersection thereof and having a radius centered at the intersection. The arcuate scale is marked in equal increments, from O at the Y coordinate to the value equal to one-quarter of the ball circumference (e.g., 63/4'') at the X coordinate. The reference line is preferably printed on a transparent sheet pivotally attached to the base sheet, and an additional indicia scale, in uniform increments equal to those of the X and Y coordinate indicia scale, is preferably printed along the reference line.
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