st other labour
in Mars, goes on continuously; the electric lamps, raised to a great
height on hollow metallic poles, affording by night a very sufficient
substitute for the light of the sun. All work is done by three relays
of artisans; the first set working from noon till evening, the next
from evening till morning, and the third from morning to noon. The
Martial day, which consists of about twenty-four hours forty minutes
of our time, is divided in a somewhat peculiar manner. The two-hour
periods, of which "mean" sunrise and sunset are severally the middle
points, are respectively called the morning and evening _zydau_. Two
periods of the same length before and after noon and midnight are
distinguished as the first and second dark, the first and second
mid-day zyda. There remain four intervals of three hours each,
popularly described as the sleeping, waking, after-sunrise, and
fore-sunset zyda respectively. This is the popular reckoning, and that
marked upon the instruments which record time for ordinary purposes,
and by these the meals and other industrial and domestic epochs are
fixed. But for purposes of exact calculation, the day, beginning an
hour before mean sunrise, is distributed into twelve periods, or
antoi, of a little more than two terrestrial hours each. These again
are subdivided by twelve into periods of a little more than 10m.,
50s., 2-1/2s., and 5/24s respectively; but of these the second and
last are alone employed in common speech. The uniform employment of
twelve as the divisor and multiplier in tables of weight, distance,
time, and space, as well as in arithmetical notation, has all the
conveniences of the decimal system of France, and some others besides
due to the greater convenience of twelve as a base. But as regards the
larger divisions of time, the Martials are placed at a great
disadvantage by the absence of any such intermediate divisions as the
Moon has suggested to Terrestrials. The revolutions of the satellites
are too rapid and their periods too brief to be of service in dividing
their year of 668-2/3 solar days. Martial civilisation having taken
its rise within the tropics--indeed the equatorial continents, which
only here and there extend far into the temperate zone, and two minor
continents in the southern ocean, are the only well-peopled portions
of the planet--the demarcation of the seasons afforded by the
solstices have been comparatively disregarded. The year is divided
into wi