David,
I understand Bryan's point and it is well taken, but in practice I don't think it holds. So long as they were trying to measure along the ground, by the contour method, a 10% error seems entirely reasonable. Have you ever used a measuring wheel? They are notoriously inaccurate because they exaggerate the measurement every nook, cranny and bump they pass over, and also because the user must walk a straight line. Another way to measure on the ground is by pacing, but this too is very inaccurate especially because of the tendency to shorten our gait when walking up or down hills. If they were using surveying equipment, then they were not following Alan Wilson's described methodology. The contour method is akin to measuring by laying a rope on the ground. T here is bound to be some slack.
We apparently:
a) do not know how they measured the 18th at Merion - by pacing it off; using a wheel; using a rope or fishing line, or even using a theodolite.
b) also don't know where the 1930 tee was.
c) don't know if where the graphic artist put the starting point for Jones' shots that is accurately where the tee was.
We do know:
a) that the 18th is 415 yards from where the graphic artist put the starting point for Jones' shots. The 17th is incorrectly done, so the 18th may be too.
b) that the hole is 455 yards from the front of the current back tee beside the 17th green.
c) that contour distance measurement will
not result in a 10% error over 450 yards, if it is competently done.
d) that you definitely need a remedial class in basic math and geometry.
In conclusion, we can draw no conclusion on your assertion that the 18th was mis-measured in 1930, or if it was, why it was. I can conclude it wouldn't have been because of contour measurement, if that was what was used, assuming that the measurer was competent.
As to the Alan Wilson "methodology", I think you read too much into what was stated. See my highlights in red below. He says that the contour approach is better, first because it's more "practical" and "easier" (i.e. they probably didn't have the tools or surveyors to do it in a straight line through the air), and secondly because it "gives a result almost identical with that of the air-line method" (Alan can skip the remedial math class
) So, he recommends the contour approach only "for the sake of practical convenience", but does suggest the use of the air-line approach where the contour requires it. Perhaps, like across the quarry on the 18th.
[italic]The question is constantly asked whether holes should be measured in an air-line or along the contour of the ground. For practical reasons the contour of the ground is usually the better method. In the first place it is much easier, and in most cases it gives a result almost identical with that of the air-line method. If the play is over rising ground followed by falling ground and then another rise, it is true that the contour method slightly increases the length, but as a large part of the play is uphill this seems entirely fair, because the hole plays long even as measured. Of course, in certain exceptional cases the air-line method should be used. Let us take, for instance, a one-shot hole of, say, 160 yards in a direct line, played from a high tee over a deep ravine to a high green beyond. The air-line measurement would be 160 yards. If a contour measurement were used, following down into the ravine and up the other side, it might show a distance of 200 yards, which would be entirely misleading, as the contour of the ravine in no way enters into the shot. In general thenfor the sake of practical convenience, holes should be measured on the contour of the ground; but in the unusual case where the contour does not enter into or affect the play of the shot, the air-line method should be used.[/italic]
The article, authored by Alan D. Wilson, may have drastically understated the impact of using the contour method on rolling terrain. Given that Wilson was a long-time member of Merion and the brother of Hugh I. Wilson, who is credited with designing both Merion Courses, Merion most likely measured using this method.
You have a number of logical fallacies in the last paragraph above. Alan didn't "drastically understate(d) the impact of using the contour method on rolling terrain". He's right and you're wrong. Perhaps they used the contour method, where appropriate and also used the air-line method where it was required. You can't infer the specific from the general.
The defense rests.