Doug, I didn’t answer your second question: "Assuming that in 1850s I had access to a good transit telescope, and a reasonable clock (daily errors about 1 second a day), how would I refine the quarter of a day into several decimal places?”
The formula is: Year = (1 day – transit time difference) / transit time difference Mike Shaw 53º22’N 3º02’W --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
