The Arizona sentinel., 1886-12-04
FAVORITE NUMBERS.

The Probably Origin of the Ordinary Sys-
 fem of Enumeration Now in Use.
 The reason why ten is favorite-per- haps the most favorite-number is obvi- ous enough, namely, that we have ten fingers. When we begin to count we almost of necessity do so with our fin- gers; if we have a large number of things to count, say flock of sheep, we instinctively divide them into tens, or perhaps into scores; if the number of things be very large the collection of tens are naturally grouped again by tens, and so we have hundreds. A further grouping of hundreds leads to thousands, and so forth. Thus we get the ordinary system of numeration, and there can be no manner of doubt that mans ten fingers are the root of it. We are told in treatises on arithmetic that it would have been much more convenient if we had agreed to count by twelves instead of by tens; and possibly this may be true.
 But, if it be, we have so much the more evidence, if evidence be needed, that inc basis of the system of counting was not determined by theoretical con. alterations, but by the simple ele- mentary fact of the number of human digits being 10 and not F. Neverthe- less 12 has its turn as a favorite num- Der; we often count by dozens, and the reason probably is that F admits of being quartered as well as halved, which in many cases is an advantage. Take the case of wine: A dozen bottles is convenient quantity to take as a stand ard, because customer can order half the standard number, or if he needs a small quantity, the quarter of the same; in fact, F adm ts of beng divided not only by , and f, but also by 3 and 6, which for many purposes give it great advantage over 10, which can be divided only by2 and ,, the latter division being rarely of any use. Hence the great divisibility of 12 is sufiic ent to mark it as favorite number; but in the most notable instance of its use, namely, as marking the number of months in a year, we need some further explana- ton. The real month, that is, the number of days between two suc- cessive full moons. may be taken as measured by 2S days. Thirteen times 2S makes 364, or, as nearly as may be, one year. Consequently, it would have been much more nearly true to say that 13 months make year than F. The explanation is to be found, I con- ceive. in the extremely awkward char acter of the number 13; it is what is called by mathematicians prime num- Der, that is to say, it admits of no di- vision of any klnd; had there been 13 i months in the year the half year and the | quarter alike would not have been reck- | oned by months, and conse luently F. | which, as already explained, is one of | the most convenient of numbers in the | matter of divisability, was encouraged | and permitted to usurp the place which | in all strictness belonged to its next | door neighbor. There is a somewhat | parallel case with regard to the division | of the circle into 360 degrees. The an- cient Chinese mathematicians divided | the circle into 365 IA degrees, corre- | spending to the length of the year, or S65 1-4 days. which number, though | not exact. is very near the truth. But 1 this division of the circle is practically intolerable; it would throw mathe- maticians into despair; consequently, | the number 360, which admits of being divided by 4, by 60, by %, and by many other numbers, usurped the place which the Chinese righteously assigned to the awkward number which nature suggest ed.-1he Bishop of Carlisle, in COntena- D0rdry ReUieIC.