The history of the Arabic or decimal notation is somewhat as follows: The characters of this notation were introduced into Europe, during the tenth century, by the Crusades. From the Arabic, these characters have been traced to the sacred books of the Brahmans of India. It was long supposed that for our modern arithmetic we were indebted to the Arabians. But this, as we have seen, is not the case. The Hindoos communicated a knowledge of it to the Arabians, and we have been unable to trace it beyond the Hindoos: hence we must concede the honor to them of its invention.
To the Arabians, however, belongs the honor of introducing arithmetic into Europe. It was the Arabians who took the torch from the Orient and passed it along toward the Occident, when "westward the star of empire took its way."
The origin of the characters came, undoubtedly, from the fact that the Orientals first learned to count on their fingers and thumbs, and from this originated the ten characters employed, and originally called digits, from the Latin word digitus, signifying finger. In keeping accounts among the Orientals, one mark represented one finger, or number, thus: 
. Two horizontal marks, with a connecting line,
stood for two, thus: 
. Three horizontal marks, with connecting lines, would stand for three, thus: 
; and four marks in the form of a square, or a triangle, would stand for four, thus: 
.
Five marks in this form, 
, was the original figure five in this notation; six marks, thus, 
, the original figure six. The figure seven was made by marks representing two squares with one of the lines wanting, thus: 
. The figure eight was made by placing two squares near each other, thus: 
; and nine by adding one or more marks to the two squares representing eight, thus: 
. The zero, or cipher, was originally a circle, and seems to have come from counting around the fingers and thumbs. Hence, once around was denoted by one finger, or character, representing one, thus: and 
; twice around, by and . From this last ar-
