e engineer was going to proceed to
ascertain the culmination of the sun, that is to say its passing the
meridian of the island or, in other words, determine due south. It was
by means of the shadow cast on the sand by the stick, a way which, for
want of an instrument, would give him a suitable approach to the result
which he wished to obtain.

In fact, the moment when this shadow would reach its minimum of length
would be exactly twelve o'clock, and it would be enough to watch the
extremity of the shadow, so as to ascertain the instant when, after
having successively diminished, it began to lengthen. By inclining his
stick to the side opposite to the sun, Cyrus Harding made the shadow
longer, and consequently its modifications would be more easily
ascertained. In fact, the longer the needle of a dial is, the more
easily can the movement of its point be followed. The shadow of the
stick was nothing but the needle of a dial. The moment had come, and
Cyrus Harding knelt on the sand, and with little wooden pegs, which he
stuck into the sand, he began to mark the successive diminutions of the
stick's shadow. His companions, bending over him, watched the operation
with extreme interest. The reporter held his chronometer in his hand,
ready to tell the hour which it marked when the shadow would be at its
shortest. Moreover, as Cyrus Harding was working on the 16th of April,
the day on which the true and the average time are identical, the hour
given by Gideon Spilett would be the true hour then at Washington, which
would simplify the calculation. Meanwhile as the sun slowly advanced,
the shadow slowly diminished, and when it appeared to Cyrus Harding that
it was beginning to increase, he asked, "What o'clock is it?"

"One minute past five," replied Gideon Spilett directly. They had now
only to calculate the operation. Nothing could be easier. It could be
seen that there existed, in round numbers, a difference of five hours
between the meridian of Washington and that of Lincoln Island, that is
to say, it was midday in Lincoln Island when it was already five o'clock
in the evening in Washington. Now the sun, in its apparent movement
round the earth, traverses one degree in four minutes, or fifteen
degrees an hour. Fifteen degrees multiplied by five hours give
seventy-five degrees.

Then, since Washington is 77deg 3' 11" as much as to say seventy-seven
degrees counted from the meridian of Greenwich which the Americans
take for