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CHAPTER XIV.
MEASURING AND WRITING.
The art of measuring brings the world into subjection to man; the art of writing prevents his knowledge from perishing with himself; together they make man, what nature has not made him, all-powerful and eternal. It is the privilege and duty of history to trace the course of national progress along these paths also.
Italian measures. Measurement necessarily presupposes the development of the several ideas of units of time, of space, and of weight, and of a whole as consisting of equal parts, or in other words of number and of a numeral system. The most obvious a presented by nature for this purpose are, in reference to time, the periodic returns of the sun and moon, or the day and the month; in reference to space, the length of the human foot, which is more easily applied in measuring than the arm; in reference to gravity, the burden which a man is able to poise (librare) on his hand while he holds his arm stretched out, or the "weight" (libra). As a a for the notion of a whole made up of equal parts, nothing so readily suggests itself as the hand with its five or the hands with their ten fingers; upon this rests the decimal system. We have already observed that these elements of all numeration and measuring reach back not merely beyond the separation of the Greek and Latin stocks but even to the most remote primeval times. The antiquity in particular of the measurement of time by the moon is demonstrated by language (P. 18); even the mode of reckoning the days that elapse between the several phases of the moon, not forward from the phase on which it had entered last, but backward from that which was next ex-
