494 THE POPULAR SCIENCE MONTHLY 



Among the ancient Semitic peoples we find separate symbols for 1, 

 10, 20 and 100. Noteworthy is the use of twenty in forming the 

 higher powers of ten; sixty is written as three twenties. The use of 

 twenty as a unit of higher order goes back to primitive counting on 

 fingers and toes, which operation still exists among Pacific coast tribes 

 of Indians, Mexicans and Esquimaux. Persistence of the unit twenty 

 is seen in our word for score; more markedly in the French quatre- 

 vingt for 80.0. 



Some time before the Christian era, the Phoenicians changed to an 

 alphabet system of numbers. The first nine letters of their alphabet 

 were given the number values 1 to 9; to the second nine attach the 

 values 10 — 90 ; and similarly with the hundreds. From the Phoenicians 

 this method was taken by the Hebrews and the Greeks. In any nu- 

 merical work the order hundreds, tens, units is strictly observed. 

 Nevertheless, as to each word there was a definite number value the 

 Hebrews indulged in secret writing by giving one name with the hint 

 to the wise to substitute some other well-known name with the same 

 number value. This near-punning occurs in the Book of the Eevela- 

 tions, " the number of the Beast is 666," referring to the Eoman 

 Emperor whose name written in Hebrew letters had the numerical 

 value, 666. 



A different type is presented by the Attic system of numbers in use 

 among the ancient Greeks, in which the symbols are the first letters of 

 the corresponding Greek words. 



1=1. 



5 = II or T from irevre for five. 

 10 = A from Se/ca for ten. 

 100 ==H from eKarov for hundred. 

 1,000 = X from x& t0L for one thousand. 

 10,000 = M from fivpiot for ten-thousand. 



Combinations r A , r H , r x , T M were used for 50, 500, 5,000 and 50,000. 

 The advantage in numerical computation of this system over the alpha- 

 bet system is great as the connection between 50, 500 and 5,000 is 

 brought out by the symbols. Deceived by the apparent simplicity of 

 the alphabet system, the Greeks abandoned the Attic in favor of the 

 alphabet form. 



y + S=£, 3+4= 7, 



A + /. = o, 30+40= 70, 



T + v = $, 300 + 400 = 700, 



are apparently simple, but they fail to show any trace of the underlying 

 decimal system. 



Ill + IIII = ni. 3 + 4 = 7. 



AAA + AAAA = T A AA. 30+ 40= 70. 



HHH + HHHH = T H HH. 300 + 400 = 700. 



