The system of notation, which is here used, is very curious.
Berosus informs us that, in their computations of time, the Chaldaeans employed an alternate sexagesimal and decimal notation, reckoning the years by the _soss,_ the _ner,_ and the _sar_--the _soss_ being a term of 60 years, the _ner_ one of 600, and the _sar_ one of 3600 (or 60 _sosses_).

It appears from the Senkareh monument, that they occasionally pursued the same practice in mere numerical calculations, as will be evident from the illustration.

[PLATE XVIII., Figs.

1, 2.] [Illustration: PLATE 18] In Arabic numerals this table may be expressed as follows: [Illustration: PAGE 66] The calculation is in every case correct; and the notation is by means of two signs--the simple wedge [--] , and the arrowhead [--] ; the wedge representing the unit, the soss (60), and the sar (3600), while the arrowhead expresses the decades of each series, or the numbers 10 and 600.

The notation is cumbrous, but scarcely more so than that of the Romans.