Greetings, fellow dialists Slawek Grzechnik wrote that you can measure the sun's diameter with a marine sextant but that you should try to avoid a mistake when reading negative angles off the vernier.
The mistake here is that Slawek has not yet sold his vernier sextant for a large profit. These sextants, beautifully engraved with silver arcs, went out with the Ark, to be replaced by micrometer sextants at least sixty years and probably more, ago. They are now much sought after by antique dealers. But if you have one to hand it is instructive to measure the diameter of both the sun and the moon at low altitude and convince yourself that the apparent large size of these bodies, e.g. the "harvest moon", is an optical illusion. Frank 55N 1W -- Frank Evans
