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As to your next most recent posting, which again seems to indicate that horizontal magnification of the Moon at the horizon is impossible, the argument that the Moon’s changing distance (you are talking about the changing distance due to the rotation of the Earth?) “exactly” compensates for the change in magnification due to refraction cannot possibly be correct.

...but can we perhaps agree that we’re both right and move on? The practical effect seems much too small to worry about.

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No, Jim, in that post I was not talking about changing distance due to the rotation of the Earth. In the post that followed I was talking about that and may have confused you. I tried to describe the situation clearly and succinctly, but apparently failed. Please reread what I wrote. If that fails again, I’ll put it another way. I was referring to the fact that when the true Moon is slightly beneath your horizon, while the center of the refracted Moon is precisely on your horizon, the true Moon is farther from you than it would be for the location at the intersection of the line connecting you with center of the Earth and the perpendicular to that line connecting to the center of the Moon. To you, the true un-refracted Moon seen by X-ray vision would appear smaller than it would to someone with X-ray vision at that other location because you are farther from the Moon. The greater distance can be calculated through the same cosine formula used for the "magnification". However, with refraction placing the image of the center of the Moon precisely on your horizon, it would appear expanded to exactly the same size as it would appear to the X-ray observer at that other location. Yes, you are correct there is an expansion along the constant azimuth lines, but it exactly compensates for the fact that the true Moon was farther from you than it was for that other location. The Moon seen through X-ray vision at that other location would have appeared 0.5° wide and the refracted Moon that seems centered on the horizon for you would also appear to be 0.5° wide. If the other observer saw a ring of 720 Moons, so would you. To both of you, all of the Moons would appear 0.5° wide.

I’ll certainly agree to your final point.

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