"A person sailing to our Antipodes westward will lose twelve hours; by sailing thither eastward he will gain twelve hours."
This is quite correct. But if one person lose twelve, and another gain twelve, the manifest difference between them is twenty-four; and yet ESTE goes on to say:
"If both meet together at the same hour, say eleven o'clock, the one will reckon 11 A.M., the other 11 P.M."
This is the misstatement. No two persons, by any correct system of reckoning, could arrive at a result which would imply a physical impossibility; and it is needless to say that the concurrence of A.M. and P.M. at the same time and place would come under that designation. What ESTE should have said is, that both persons meeting { 649} together on the same day, if it be reckoned Monday by the one, it will be reckoned Tuesday by the other. They may differ as to Monday or Tuesday, but they cannot rationally differ as to whether it is day or night.
It may be added that, no matter where these two persons might meet, whether at the Antipodes or at any other place, still, upon comparing their journals, there would always appear a day's difference between them; and if they were to keep continually sailing on, one always towards the west, and the other always towards the east, every time they might meet or cross each other, they would increase the difference between them by an additional day.
Whence it follows, that if two ships were to leave England on the same day, one sailing east by the Cape of Good Hope, and the other west by Cape Horn, returning home respectively by the opposite capes; and if both were to arrive again in England at the same time, there would be found in the reckoning of the eastern vessel two entire days more than in that of the western vessel. Nor would this difference be merely theoretic or imaginary; on the contrary, it would be a real and substantial gain on the part of the eastern vessel: her crew would have consumed two whole rations of breakfast, dinner, and supper, and swallowed two days' allowance of grog more than the other crew; and they would have enjoyed two nights more sleep.
But all this is not an answer to H's question; what he wants to know is whether the day at the Antipodes is twelve hours in advance or in arrear of our day and, whichever it is, why is it?