civilisation. It is so intimately connected with
all our wants, it is so completely the regulator
of all our occupations, that we have become,
as it were, its slaves; and we can no more
imagine a state of social existence without it,
than we can imagine birds flying without wings,
or any other thing that is totally impossible.

The first people who appear to have allotted
the day into portions were the Assyrians,
who invented the water clock, at a
period too remote for precise calculation. All
we know for certain is, that the apparatus
existed before the overthrow of the first
Assyrian empire by Arbaces and Belesis, in the
year 759 B.C., for we find by the tradition of
early Persian authors that the use of it was
general in Nineveh under the reign of Phul,
better known as Sardanapalus the Second, the
first monarch of the second Assyrian empire.
This water clock was nothing more than a brass
vessel of cylindrical shape, holding several
gallons of water. A very small hole was bored
in one of its sides, through which the liquid
was allowed to trickle; and it was calculated
that the vessel could empty itself about five or
six times in a day. Under the reign of Phul,
the royal palace of Nineveh, and each of the
principal districts of the city, possessed a water
clock of the same shape and capacity. They
were filled together, or as nearly as possible
together, at the signal of a watchman stationed
aloft on a tower to proclaim the rising of the
sun, and they remained all day in the keeping
of officials, whose business it was to fill them
as soon as they became empty. There was a
regular staff of criers employed in connexion
with each of the time offices, and as often as
the water clocks were replenished they spread
through the streets shouting out the fact for
the benefit of the townspeople. In this way a
sort of rough computation of the flight of time
was held. The intervals between the filling
and emptying of the vessels were called
"watches," and were, probably, of two hours
or two hours and a half's duration. But it is
hard to suppose that the water clocks kept
very steady pace with each other; the
difficulty of making by hand vessels of exactly
the same size, of drilling them with holes of
precisely the same diameter, and of supplying
them with water of just the same density,
must have given rise to even more irregularity
in the working of these machines than exists
at present in the movements of our city clocks:
those clocks of which Charles Lamb said that
they allowed him to walk from the Strand to
Temple Bar in no time, and gain five minutes!

The water clock, or clepsydra, continued to
remain in its primitive condition for many
centuries; and it was not until the invention of
the sun-dial at Alexandria, five hundred and
fifty-eight years before Christ, that it underwent
any improvement. About that time, however,
an Egyptian, of Memphis, added a dial
with a hand to the clepsydra. The hand
revolved on a pivot, and communicated with a
string which was fastened to a float. As the
water leaked out, the float fell with it, and the
tension of the string caused the hand to move
round with slight spasmodic jerks, something
like those of the second-hand on a watch of
inferior make. This reform, meritorious enough
in theory, proved somewhat deficient in
practice; for the old difficulty about getting the
clocks to keep step was doubled or trebled when
the system became complicated with dial, needle,
string, and float. To ensure simultaneous
acting, the string or wire of the different clocks
ought to have been of the same length and
force; the needles also ought to have been of a
size and set on pivots exactly similar in point
of height and circumference. And when all
this had been obtained, there was still the
question as to how to make float and string,
string and needle, act in perfect unison. Often,
through rust, or some other cause, the needle
must have proved obdurate to the faint tug of
the string, and the float, in consequence, have
remained suspended in mid air; whereupon, of
course, the dial became mute, and Egyptians,
who disliked innovations, must have shrugged
their shoulders. But, notwithstanding its
drawbacks, the improvement was a very
valuable one, if for no other reason than that
it prepared the way for further changes, and
led to the perfecting of the clepsydra by the
substitution of a system of dented wheels for
that already in use. The wheels were set at
work on the water-mill principle, and the addition
of a second needle to the dial allowed the
clock to mark the fractions of the different
"watches." This was the ne plus ultra as
far as the clepsydra was concerned; it dates
from two hundred and fifty years before Christ,
and Egypt, which had become the great mart
of the new timepieces, exported them to the
different countries of the East as rare
curiosities, and at fabulous prices. When Pompey
returned to Rome, in the year sixty-two before
Christ, from triumphing over Tigranes, Antiochus,
and Mithridates, one of the most valuable
trophies he brought with him from the treasures
of the King of Pontus was a clepsydra,
marking the hours and minutes according to
the method of horology in use at Rome. The
cylinder which served as receptacle for the
water was of gold, as was also the dial-plate.
The hands were studded with small rubies, and
each of the cyphers that denoted the twenty-
four hours was cut out of a sapphire. It must
have been of enormous size, for the cylinder
only needed replenishing once a day. The
Romans had never seen anything like it, and
when Pompey caused it to be set up in the
chief hall of the Capitol, it needed a strong
guard of soldiers to protect it against the
indiscreet curiosity of the mob.

We come now to those ages of total darkness
which followed the overthrow of the Roman
Empire, when science, art, and everything that
was refined fell into contempt and oblivion.
The barbarians who conquered the imperial
city had very primitive modes of marking the
course of time. They knew nothing about
hours and minutes; they had not sense enough
to invent water-clocks, and sun-dials, even had