Elementary arithmetic, with brief notices of its history... by Robert Potts.

ON THE DIVISIONS AND MEASURES OF TIME.

9

day into twelve parts, the Greeks learned from the Babylonians."
The division of the natural day into twenty-four equal parts is of
ancient date, and each of these equal parts is named an hour. The
word Wpca was not known in Greece so early as the age of Anaximander, yet it is probable that the division of the period of daylight
into twelve equal parts was in use. Nor was the word Ahora known
at Rome for 300 years after the foundation of the city.
The hour was also divided into sixty equal parts, called minutes,
the ninute into sixty equal parts, called second minutes, afterwards
abbreviated into seconds, and so on. This division of the hour, &c.,
most probably was taken from the sexagesimal division of the degree,
or the 360th part of the circumference of a circle.
In the history of mankind, certain points of time, called epochs,
have been noted, from which periods of time have been reckoned, as
the date of the Exodus from Egypt by the Hebrews, of the First
Olympiad by the Greeks, of the Building of the City of Rome by the
Romans, or of the Birth of Christ. A series of years not defined but
reckoned from some fixed epoch is called an era, as the Christian era,
and this differs from a period of time, which is supposed to have its
beginning and ending fixed.
It appears the more desirable plan to adopt the chronology of the
Hebrew Scriptures in connecting the history of ancient nations, as far
as the correctness of it can be determined. The early periods of
Grecian and Roman history are involved in fabulous uncertainty. It
was the object of heathen priests to invest in mystery and in obscurity the events of early times, the origin of their rites and superstitions, and the exploits of those heroes they worshipped as gods.
They were careful also to refer events to an antiquity beyond all
record, and by artifice and ingenuity to keep the minds of their
deluded votaries from any scrutiny into the truth and origin of tho
superstitions they found advantageous both for their own power and
profit.1
mention is made of a protection granted by Edw. III. in 1368 to two Dutchmen who
were clockmakers to exercise their trade in England. And it is not improbable that
the clock set up at Westminster in 1368 A.D. was constructed by these artists.
It was, however, found to be imperfect. Richard Walilgford of St. Albans, in the
reign of Eichard II., 1377-13'9, made a clock for the Abbey at that place. The
clock set up at Hampton Court Palace, 1510, was the first which kept time with
regularity. Clocks were made portable about 1530, but were not in general use till
1631, and the balance clock, then in use, received its greatest improvement in the
substitution of the pendulum for the balance by I-Huyghens, in 1649. The idea of
employing the pendulum was first suggested by Galileo, who had noted the regularity
and equality of its vibrations. Watches were invented at Nuremburg in 1477 by
a German, and appear to have undergone considerable imlprovements before 1530.
They were brought to Englanid in 1577, and about eighty years after that time
Hooke invented the spring pocket watches, which were followed in 1676 by Barlow's
repeaters. -See Treatise on Watch-work, by the Rev. H. L. TNelthrolp, 1873.
1 From the fact of the early prevalence of the worship of the host of heavein, the
aspects and mnotions of the sui, moon, and the planets engaged the attention of
manlkind. In the progress of idolatry, powers and influences were ascribed to theo
planets and constellations, supposed by their aspects to forebode good and evil to
men. Those who studied the stars imposed on the ignorance of the people and
framed the science of Astrology. This superstition prevailed in the neighbouring
countries of Judea (Jer. x. 2). It was common in Chaldea (Dan. ii. 2). It prevailed long before in Egypt, and was professed both in Greece and Rome; and the
superstition is still found in almost every country. That people under the influence
of such mistaken notions should be alarmed at eclipses, as Nicias was (Thucyd.