MODES OF KEEPING TIME KNOWN AMONG THE CHINESE. 
*By D. J. MAGOwAN, M. D. 
According to the Shu-king, we find that forty-five centuries ago the 
Chinese had occupied themselves with the construction of astronomical 
instruments analogous to the quadrant and armillary sphere; the 
observations they made with them, even at that remote period, are 
remarkable for their accuracy, enabling them to form a useful calendar. 
The present sexagenary cycle was adopted B. C. 2636, by Hwangti, to 
whom is attributed the invention of the clepsydra. The instrument at 
that period was probably very rude, used principally for astronomical 
purposes in the same manner as employed by Tycho Brahe for measur- 
ing the motion of stars, and subsequently by Dudelz in making mari- 
time observations. It was committed to the care of an officer styled 
the clepsydra adjuster. 
Duke Chan, the alleged inventor of the compass, about B. c. 1130, 
appears also to have been the first to employ the clepsydra as a time- 
piece. He divided the floating index into one hundred kih, or parts. 
In winter forty kih were allotted for the day and sixty for the night; 
in summer this was reversed, the spring and autum being equally 
divided. This instrument was provided with forty-eight indices, two 
for each of the twenty-four tsieh, or terms of the year. They were con- 
sequently changed semi-monthly, one index being employed for the day 
and another for the night. Two were employed every day, probably to 
remedy in a measure the defect of all clepsydras, 7. ¢., of varying in the 
speed of their rise and fall, according to the ever-varying quantity of 
water in the vessel, which might be done by having the indices differ- 
ently divided. To keep the water from freezing, the instrument was 
connected with a furnace, and surrounded with hot water. The forms 
of the apparatusthave been various, but they generally consisted of an 
upper and a lower copper vessel, the former having an aperture in the 
bottom through which water percolated into the latter, where floated 
an index, the gradual rise of which indicated successive periods of time. 
*From Chinese Repository, July, 1851. 
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