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A New Method of Measuring Pin-Hole Golds
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I have had made as a model a triangular steel frame with clips to hold a slip of cardboard; this is a rather more elaborate pattern, and consequently more expensive; but if the process is adopted, that is to say, is introduced at the public meetings, this steel frame would undoubtedly be the best. Several could be procured of uniform size with the incision and reference marks accurately cut out by machinery, and could be distributed to the five public societies for use at their respective meetings. One important point in this method of measurement is that the circumference of the gold circle should be sharp and well defined. On close examination the edge of the gold circle tends, at intervals, to become a little ragged and uneven. To obviate any difficulty which might arise if a measurement had to be made to one of these stretches of irregular and ill-defined curvature, it is proposed, merely as a precautionary measure, that, before the targets are used, instead of marking the cross-lines through the centre as is now the custom, to describe a true fine circle from the centre of the gold circle of the exact radius of 121.9 mm. (4.8 inches) which would cut off or pass beyond any projections or depressions on the circumference of the actual gold, and which would serve as a true circumference to measure to. This fine circle can be easily described by having two small holes, which will just admit an ordinary pin, drilled in the base of the steel frame exactly 121.9 mm. (4.8 inches) apart. The frame can be pinned on to the centre of the target by one hole, and then, if the point of another pin is passed lightly through the second hole, by revolving the frame round the central pin a fine and accurate . circle can be traced completely round the jagged edge of the gold. Earlier in this article I had occasion to state that for all practical purposes the diameters of all men's arrows could be regarded as equal, and the same statement applies even more strongly to all ladies' arrows. Careful measurement with a vernier scale of the diameters of many arrows of varying weights and lengths at a distance of 4 inches and 3 inches respectively above the pile give the mean diameter in the first case as 8.00 mm. (.31 inches) and in the second as 7.12 mm. (.28 inches), and the difference between these mean diameters and the diameters of arrows of unusual length and weight is so small that it is most unlikely even in an extreme case if it would cause an error in the ultimate measurement of more than .25 mm. (.01 inches), a difference scarcely visible to the naked eye, and far too small to be detected and noted, considering the conditions and the appliances.
In conclusion I should like to refer briefly to the two articles which have already appeared on this subject in the Archer's Register of 1878 and 1892. In the first the inventor of the present system—Mr. E. W. Hussey—fully appreciates the unimportance of the varying diameters of arrows, except in the two broad divisions already mentioned. "Judex" in 1892, however, is far more ambitious, claiming that this mode of measurement discovered an excess in girth of one lady's arrow in a case where two pin-hole golds were made at consecutive ends.
If the card had correctly fitted either one of the two arrows this astonishing obesity would have been disclosed on the spot, as should also have been the fact that it would be useless to expect any such refined results as those claimed without preparing a second card to fit the other arrow accurately.
The most central of the two arrows might have been as thick as a scaffolding-pole without in the least affecting the result, provided that it was measured with a card that fitted, and it, is precisely on this last condition that any niceties of measurement depend. To ignore the varying "bulks" of the arrows while actually conducting the process of measurement—which must have been the case if only one card was used—and then to assert that this variation in diameter made itself gradually evident in the course of constructing a diagram entirely dependent on this measurement was about as ridiculous a conclusion as could well have been arrived at.