CHAPTER I.

Produced by Jonathan Ingram, Hagen von Eitzen and the

Online Distributed Proofreading Team at https://www.pgdp.net

[*Transcriber's Note:

The following errors found in the original have been left as is.

Chapter I, 14th paragraph:

drop double quote before 'It is said';

Chapter IV, 1st paragraph:

'so similar than' read 'so similar that';

Chapter IV, table of Hebrew numerals (near footnote 144):

insert comma after 'shemoneh';

Chapter V, table of Tahuatan numerals (near footnote 201):

'tahi,' read 'tahi.';

Same table:

' 20,000. tufa' read '200,000. tufa';

Chapter VI, table of Bagrimma numerals (near footnote 259):

'marta = 5 + 2' read 'marta = 5 + 3';

Same table:

'do-so = [5] + 3' read 'do-so = [5] + 4';

Chapter VII, table of Nahuatl numerals (near footnote 365):

'90-10' read '80-10';

In paragraph following that table:

'+ (15 + 4) × 400 × 800' read

'(15 + 4) × 20 × 400 × 8000 + (15 + 4) × 400 × 8000';

In text of footnote 297:

'II. I. p. 179' read 'II. i. p. 179';

*]

THE MACMILLAN COMPANY

NEW YORK · BOSTON · CHICAGO · DALLAS

ATLANTA · SAN FRANCISCO

MACMILLAN & CO., LIMITED

LONDON · BOMBAY · CALCUTTA

MELBOURNE

THE MACMILLAN COMPANY

OF CANADA, LIMITED

TORONTO

THE NUMBER CONCEPT

ITS ORIGIN AND DEVELOPMENT

BY

LEVI LEONARD CONANT, PH.D.

ASSOCIATE PROFESSOR OF MATHEMATICS IN THE WORCESTER

POLYTECHNIC INSTITUTE

New York

MACMILLAN AND CO.

AND LONDON

1931

COPYRIGHT, 1896,

BY THE MACMILLAN COMPANY.

COPYRIGHT, 1924,

BY EMMA B. CONANT.

All rights reserved--no part of this book may be reproduced in any form

without permission in writing from the publisher.

Set up and electrotyped. Published July, 1896.

Norwood Press

J.S. Cushing Co.--Berwick & Smith Co.

Norwood, Mass., U.S.A.

PREFACE.

In the selection of authorities which have been consulted in the

preparation of this work, and to which reference is made in the following

pages, great care has been taken. Original sources have been drawn upon in

the majority of cases, and nearly all of these are the most recent

attainable. Whenever it has not been possible to cite original and recent

works, the author has quoted only such as are most standard and

trustworthy. In the choice of orthography of proper names and numeral

words, the forms have, in almost all cases, been written as they were

found, with no attempt to reduce them to a systematic English basis. In

many instances this would have been quite impossible; and, even if

possible, it would have been altogether unimportant. Hence the forms,

whether German, French, Italian, Spanish, or Danish in their transcription,

are left unchanged. Diacritical marks are omitted, however, since the

proper key could hardly be furnished in a work of this kind.

With the above exceptions, this study will, it is hoped, be found to be

quite complete; and as the subject here investigated has never before been

treated in any thorough and comprehensive manner, it is hoped that this

book may be found helpful. The collections of numeral systems illustrating

the use of the binary, the quinary, and other number systems, are, taken

together, believed to be the most extensive now existing in any language.

Only the cardinal numerals have been considered. The ordinals present no

marked peculiarities which would, in a work of this kind, render a separate

discussion necessary. Accordingly they have, though with some reluctance,

been omitted entirely.

Sincere thanks are due to those who have assisted the author in the

preparation of his materials. Especial acknowledgment should be made to

Horatio Hale, Dr. D.G. Brinton, Frank Hamilton Cushing, and Dr. A.F.

Chamberlain.

WORCESTER, MASS., Nov. 12, 1895.

CONTENTS.

Chapter I.

Counting 1

Chapter II.

Number System Limits 21

Chapter III.

Origin of Number Words 37

Chapter IV.

Origin of Number Words (_continued_) 74

Chapter V.

Miscellaneous Number Bases 100

Chapter VI.

The Quinary System 134

Chapter VII.

The Vigesimal System 176

* * * * *

Index 211

THE NUMBER CONCEPT: ITS ORIGIN AND DEVELOPMENT.

CHAPTER I.

COUNTING.

Among the speculative questions which arise in connection with the study of

arithmetic from a historical standpoint, the origin of number is one that

has provoked much lively discussion, and has led to a great amount of

learned research among the primitive and savage languages of the human

race. A few simple considerations will, however, show that such research

must necessarily leave this question entirely unsettled, and will indicate

clearly that it is, from the very nature of things, a question to which no

definite and final answer can be given.

Among the barbarous tribes whose languages have been studied, even in a

most cursory manner, none have ever been discovered which did not show some

familiarity with the number concept. The knowledge thus indicated has often

proved to be most limited; not extending beyond the numbers 1 and 2, or 1,

2, and 3. Examples of this poverty of number knowledge are found among the

forest tribes of Brazil, the native races of Australia and elsewhere, and

they are considered in some detail in the next chapter. At first thought it

seems quite inconceivable that any human being should be destitute of the

power of counting beyond 2. But such is the case; and in a few instances

languages have been found to be absolutely destitute of pure numeral words.

The Chiquitos of Bolivia had no real numerals whatever,[1] but expressed

their idea for "one" by the word _etama_, meaning alone. The Tacanas of the

same country have no numerals except those borrowed from Spanish, or from

Aymara or Peno, languages with which they have long been in contact.[2] A

few other South American languages are almost equally destitute of numeral

words. But even here, rudimentary as the number sense undoubtedly is, it is

not wholly lacking; and some indirect expression, or some form of

circumlocution, shows a conception of the difference between _one_ and

_two_, or at least, between _one_ and _many_.

These facts must of necessity deter the mathematician from seeking to push

his investigation too far back toward the very origin of number.

Philosophers have endeavoured to establish certain propositions concerning

this subject, but, as might have been expected, have failed to reach any

common ground of agreement. Whewell has maintained that "such propositions

as that two and three make five are necessary truths, containing in them an

element of certainty beyond that which mere experience can give." Mill, on

the other hand, argues that any such statement merely expresses a truth

derived from early and constant experience; and in this view he is heartily

supported by Tylor.[3] But why this question should provoke controversy, it

is difficult for the mathematician to understand. Either view would seem to

be correct, according to the standpoint from which the question is

approached. We know of no language in which the suggestion of number does

not appear, and we must admit that the words which give expression to the

number sense would be among the early words to be formed in any language.

They express ideas which are, at first, wholly concrete, which are of the

greatest possible simplicity, and which seem in many ways to be clearly

understood, even by the higher orders of the brute creation. The origin of

number would in itself, then, appear to lie beyond the proper limits of

inquiry; and the primitive conception of number to be fundamental with

human thought.

In connection with the assertion that the idea of number seems to be

understood by the higher orders of animals, the following brief quotation

from a paper by Sir John Lubbock may not be out of place: "Leroy ...

mentions a case in which a man was anxious to shoot a crow. 'To deceive

this suspicious bird, the plan was hit upon of sending two men to the watch

house, one of whom passed on, while the other remained; but the crow

counted and kept her distance. The next day three went, and again she

perceived that only two retired. In fine, it was found necessary to send

five or six men to the watch house to put her out in her calculation. The

crow, thinking that this number of men had passed by, lost no time in

returning.' From this he inferred that crows could count up to four.

Lichtenberg mentions a nightingale which was said to count up to three.

Every day he gave it three mealworms, one at a time. When it had finished

one it returned for another, but after the third it knew that the feast was

over.... There is an amusing and suggestive remark in Mr. Galton's

interesting _Narrative of an Explorer in Tropical South Africa_. After

describing the Demara's weakness in calculations, he says: 'Once while I

watched a Demara floundering hopelessly in a calculation on one side of me,

I observed, "Dinah," my spaniel, equally embarrassed on the other; she was

overlooking half a dozen of her new-born puppies, which had been removed

two or three times from her, and her anxiety was excessive, as she tried to

find out if they were all present, or if any were still missing. She kept

puzzling and running her eyes over them backwards and forwards, but could

not satisfy herself. She evidently had a vague notion of counting, but the

figure was too large for her brain. Taking the two as they stood, dog and

Demara, the comparison reflected no great honour on the man....' According

to my bird-nesting recollections, which I have refreshed by more recent

experience, if a nest contains four eggs, one may safely be taken; but if

two are removed, the bird generally deserts. Here, then, it would seem as

if we had some reason for supposing that there is sufficient intelligence

to distinguish three from four. An interesting consideration arises with

reference to the number of the victims allotted to each cell by the

solitary wasps. One species of Ammophila considers one large caterpillar of

_Noctua segetum_ enough; one species of Eumenes supplies its young with

five victims; another 10, 15, and even up to 24. The number appears to be

constant in each species. How does the insect know when her task is

fulfilled? Not by the cell being filled, for if some be removed, she does

not replace them. When she has brought her complement she considers her

task accomplished, whether the victims are still there or not. How, then,

does she know when she has made up the number 24? Perhaps it will be said

that each species feels some mysterious and innate tendency to provide a

certain number of victims. This would, under no circumstances, be any

explanation; but it is not in accordance with the facts. In the genus

Eumenes the males are much smaller than the females.... If the egg is male,

she supplies five; if female, 10 victims. Does she count? Certainly this

seems very like a commencement of arithmetic."[4]

Many writers do not agree with the conclusions which Lubbock reaches;

maintaining that there is, in all such instances, a perception of greater

or less quantity rather than any idea of number. But a careful

consideration of the objections offered fails entirely to weaken the

argument. Example after example of a nature similar to those just quoted

might be given, indicating on the part of animals a perception of the

difference between 1 and 2, or between 2 and 3 and 4; and any reasoning

which tends to show that it is quantity rather than number which the animal

perceives, will apply with equal force to the Demara, the Chiquito, and the

Australian. Hence the actual origin of number may safely be excluded from

the limits of investigation, and, for the present, be left in the field of

pure speculation.

A most inviting field for research is, however, furnished by the primitive

methods of counting and of giving visible expression to the idea of number.

Our starting-point must, of course, be the sign language, which always

precedes intelligible speech; and which is so convenient and so expressive

a method of communication that the human family, even in its most highly

developed branches, never wholly lays it aside. It may, indeed, be stated

as a universal law, that some practical method of numeration has, in the

childhood of every nation or tribe, preceded the formation of numeral

words.

Practical methods of numeration are many in number and diverse in kind. But

the one primitive method of counting which seems to have been almost

universal throughout all time is the finger method. It is a matter of

common experience and observation that every child, when he begins to

count, turns instinctively to his fingers; and, with these convenient aids

as counters, tallies off the little number he has in mind. This method is

at once so natural and obvious that there can be no doubt that it has

always been employed by savage tribes, since the first appearance of the

human race in remote antiquity. All research among uncivilized peoples has

tended to confirm this view, were confirmation needed of anything so

patent. Occasionally some exception to this rule is found; or some

variation, such as is presented by the forest tribes of Brazil, who,

instead of counting on the fingers themselves, count on the joints of their

fingers.[5] As the entire number system of these tribes appears to be

limited to _three_, this variation is no cause for surprise.

The variety in practical methods of numeration observed among savage races,

and among civilized peoples as well, is so great that any detailed account

of them would be almost impossible. In one region we find sticks or splints

used; in another, pebbles or shells; in another, simple scratches, or

notches cut in a stick, Robinson Crusoe fashion; in another, kernels or

little heaps of grain; in another, knots on a string; and so on, in

diversity of method almost endless. Such are the devices which have been,

and still are, to be found in the daily habit of great numbers of Indian,

negro, Mongolian, and Malay tribes; while, to pass at a single step to the

other extremity of intellectual development, the German student keeps his

beer score by chalk marks on the table or on the wall. But back of all

these devices, and forming a common origin to which all may be referred, is

the universal finger method; the method with which all begin, and which all

find too convenient ever to relinquish entirely, even though their

civilization be of the highest type. Any such mode of counting, whether

involving the use of the fingers or not, is to be regarded simply as an

extraneous aid in the expression or comprehension of an idea which the mind

cannot grasp, or cannot retain, without assistance. The German student

scores his reckoning with chalk marks because he might otherwise forget;

while the Andaman Islander counts on his fingers because he has no other

method of counting,--or, in other words, of grasping the idea of number. A

single illustration may be given which typifies all practical methods of

numeration. More than a century ago travellers in Madagascar observed a

curious but simple mode of ascertaining the number of soldiers in an

army.[6] Each soldier was made to go through a passage in the presence of

the principal chiefs; and as he went through, a pebble was dropped on the

ground. This continued until a heap of 10 was obtained, when one was set

aside and a new heap begun. Upon the completion of 10 heaps, a pebble was

set aside to indicate 100; and so on until the entire army had been

numbered. Another illustration, taken from the very antipodes of

Madagascar, recently found its way into print in an incidental manner,[7]

and is so good that it deserves a place beside de Flacourt's time-honoured

example. Mom Cely, a Southern negro of unknown age, finds herself in debt

to the storekeeper; and, unwilling to believe that the amount is as great

as he represents, she proceeds to investigate the matter in her own

peculiar way. She had "kept a tally of these purchases by means of a

string, in which she tied commemorative knots." When her creditor

"undertook to make the matter clear to Cely's comprehension, he had to

proceed upon a system of her own devising. A small notch was cut in a

smooth white stick for every dime she owed, and a large notch when the

dimes amounted to a dollar; for every five dollars a string was tied in the

fifth big notch, Cely keeping tally by the knots in her bit of twine; thus,

when two strings were tied about the stick, the ten dollars were seen to be

an indisputable fact." This interesting method of computing the amount of

her debt, whether an invention of her own or a survival of the African life

of her parents, served the old negro woman's purpose perfectly; and it

illustrates, as well as a score of examples could, the methods of

numeration to which the children of barbarism resort when any number is to

be expressed which exceeds the number of counters with which nature has

provided them. The fingers are, however, often employed in counting numbers

far above the first decade. After giving the Il-Oigob numerals up to 60,

Müller adds:[8] "Above 60 all numbers, indicated by the proper figure

pantomime, are expressed by means of the word _ipi_." We know, moreover,

that many of the American Indian tribes count one ten after another on

their fingers; so that, whatever number they are endeavouring to indicate,

we need feel no surprise if the savage continues to use his fingers

throughout the entire extent of his counts. In rare instances we find

tribes which, like the Mairassis of the interior of New Guinea, appear to

use nothing but finger pantomime.[9] This tribe, though by no means

destitute of the number sense, is said to have no numerals whatever, but to

use the single word _awari_ with each show of fingers, no matter how few or

how many are displayed.

In the methods of finger counting employed by savages a considerable degree

of uniformity has been observed. Not only does he use his fingers to assist

him in his tally, but he almost always begins with the little finger of his

left hand, thence proceeding towards the thumb, which is 5. From this point

onward the method varies. Sometimes the second 5 also is told off on the

left hand, the same order being observed as in the first 5; but oftener the

fingers of the right hand are used, with a reversal of the order previously

employed; _i.e._ the thumb denotes 6, the index finger 7, and so on to the

little finger, which completes the count to 10.

At first thought there would seem to be no good reason for any marked

uniformity of method in finger counting. Observation among children fails

to detect any such thing; the child beginning, with almost entire

indifference, on the thumb or on the little finger of the left hand. My own

observation leads to the conclusion that very young children have a slight,

though not decided preference for beginning with the thumb. Experiments in

five different primary rooms in the public schools of Worcester, Mass.,

showed that out of a total of 206 children, 57 began with the little finger

and 149 with the thumb. But the fact that nearly three-fourths of the

children began with the thumb, and but one-fourth with the little finger,

is really far less significant than would appear at first thought. Children

of this age, four to eight years, will count in either way, and sometimes

seem at a loss themselves to know where to begin. In one school room where

this experiment was tried the teacher incautiously asked one child to count

on his fingers, while all the other children in the room watched eagerly to

see what he would do. He began with the little finger--and so did every

child in the room after him. In another case the same error was made by the

teacher, and the child first asked began with the thumb. Every other child

in the room did the same, each following, consciously or unconsciously, the

example of the leader. The results from these two schools were of course

rejected from the totals which are given above; but they serve an excellent

purpose in showing how slight is the preference which very young children

have in this particular. So slight is it that no definite law can be

postulated of this age; but the tendency seems to be to hold the palm of

the hand downward, and then begin with the thumb. The writer once saw a boy

about seven years old trying to multiply 3 by 6; and his method of

procedure was as follows: holding his left hand with its palm down, he

touched with the forefinger of his right hand the thumb, forefinger, and

middle finger successively of his left hand. Then returning to his

starting-point, he told off a second three in the same manner. This process

he continued until he had obtained 6 threes, and then he announced his

result correctly. If he had been a few years older, he might not have

turned so readily to his thumb as a starting-point for any digital count.

The indifference manifested by very young children gradually disappears,

and at the age of twelve or thirteen the tendency is decidedly in the

direction of beginning with the little finger. Fully three-fourths of all

persons above that age will be found to count from the little finger toward

the thumb, thus reversing the proportion that was found to obtain in the

primary school rooms examined.

With respect to finger counting among civilized peoples, we fail, then, to

find any universal law; the most that can be said is that more begin with

the little finger than with the thumb. But when we proceed to the study of

this slight but important particular among savages, we find them employing

a certain order of succession with such substantial uniformity that the

conclusion is inevitable that there must lie back of this some well-defined

reason, or perhaps instinct, which guides them in their choice. This

instinct is undoubtedly the outgrowth of the almost universal

right-handedness of the human race. In finger counting, whether among

children or adults, the beginning is made on the left hand, except in the

case of left-handed individuals; and even then the start is almost as

likely to be on the left hand as on the right. Savage tribes, as might be

expected, begin with the left hand. Not only is this custom almost

invariable, when tribes as a whole are considered, but the little finger is

nearly always called into requisition first. To account for this

uniformity, Lieutenant Gushing gives the following theory,[10] which is

well considered, and is based on the results of careful study and

observation among the Zuñi Indians of the Southwest: "Primitive man when

abroad never lightly quit hold of his weapons. If he wanted to count, he

did as the Zuñi afield does to-day; he tucked his instrument under his left

arm, thus constraining the latter, but leaving the right hand free, that he

might check off with it the fingers of the rigidly elevated left hand. From

the nature of this position, however, the palm of the left hand was

presented to the face of the counter, so that he had to begin his score on

the little finger of it, and continue his counting from the right leftward.

An inheritance of this may be detected to-day in the confirmed habit the

Zuñi has of gesticulating from the right leftward, with the fingers of the

right hand over those of the left, whether he be counting and summing up,

or relating in any orderly manner." Here, then, is the reason for this

otherwise unaccountable phenomenon. If savage man is universally

right-handed, he will almost inevitably use the index finger of his right

hand to mark the fingers counted, and he will begin his count just where it

is most convenient. In his case it is with the little finger of the left

hand. In the case of the child trying to multiply 3 by 6, it was with the

thumb of the same hand. He had nothing to tuck under his arm; so, in

raising his left hand to a position where both eye and counting finger

could readily run over its fingers, he held the palm turned away from his

face. The same choice of starting-point then followed as with the

savage--the finger nearest his right hand; only in this case the finger was

a thumb. The deaf mute is sometimes taught in this manner, which is for him

an entirely natural manner. A left-handed child might be expected to count

in a left-to-right manner, beginning, probably, with the thumb of his right

hand.

To the law just given, that savages begin to count on the little finger of

the left hand, there have been a few exceptions noted; and it has been

observed that the method of progression on the second hand is by no means

as invariable as on the first. The Otomacs[11] of South America began their

count with the thumb, and to express the number 3 would use the thumb,

forefinger, and middle finger. The Maipures,[12] oddly enough, seem to have

begun, in some cases at least, with the forefinger; for they are reported

as expressing 3 by means of the fore, middle, and ring fingers. The

Andamans[13] begin with the little finger of either hand, tapping the nose

with each finger in succession. If they have but one to express, they use

the forefinger of either hand, pronouncing at the same time the proper

word. The Bahnars,[14] one of the native tribes of the interior of Cochin

China, exhibit no particular order in the sequence of fingers used, though

they employ their digits freely to assist them in counting. Among certain

of the negro tribes of South Africa[15] the little finger of the right hand

is used for 1, and their count proceeds from right to left. With them, 6 is

the thumb of the left hand, 7 the forefinger, and so on. They hold the palm

downward instead of upward, and thus form a complete and striking exception

to the law which has been found to obtain with such substantial uniformity

in other parts of the uncivilized world. In Melanesia a few examples of

preference for beginning with the thumb may also be noticed. In the Banks

Islands the natives begin by turning down the thumb of the right hand, and

then the fingers in succession to the little finger, which is 5. This is

followed by the fingers of the left hand, both hands with closed fists

being held up to show the completed 10. In Lepers' Island, they begin with

the thumb, but, having reached 5 with the little finger, they do not pass

to the other hand, but throw up the fingers they have turned down,

beginning with the forefinger and keeping the thumb for 10.[16] In the use

of the single hand this people is quite peculiar. The second 5 is almost

invariably told off by savage tribes on the second hand, though in passing

from the one to the other primitive man does not follow any invariable law.

He marks 6 with either the thumb or the little finger. Probably the former

is the more common practice, but the statement cannot be made with any

degree of certainty. Among the Zulus the sequence is from thumb to thumb,

as is the case among the other South African tribes just mentioned; while

the Veis and numerous other African tribes pass from thumb to little

finger. The Eskimo, and nearly all the American Indian tribes, use the

correspondence between 6 and the thumb; but this habit is by no means

universal. Respecting progression from right to left or left to right on

the toes, there is no general law with which the author is familiar. Many

tribes never use the toes in counting, but signify the close of the first

10 by clapping the hands together, by a wave of the right hand, or by

designating some object; after which the fingers are again used as before.

One other detail in finger counting is worthy of a moment's notice. It

seems to have been the opinion of earlier investigators that in his passage

from one finger to the next, the savage would invariably bend down, or

close, the last finger used; that is, that the count began with the fingers

open and outspread. This opinion is, however, erroneous. Several of the

Indian tribes of the West[17] begin with the hand clenched, and open the

fingers one by one as they proceed. This method is much less common than

the other, but that it exists is beyond question.

In the Muralug Island, in the western part of Torres Strait, a somewhat

remarkable method of counting formerly existed, which grew out of, and is

to be regarded as an extension of, the digital method. Beginning with the

little finger of the left hand, the natives counted up to 5 in the usual

manner, and then, instead of passing to the other hand, or repeating the

count on the same fingers, they expressed the numbers from 6 to 10 by

touching and naming successively the left wrist, left elbow, left shoulder,

left breast, and sternum. Then the numbers from 11 to 19 were indicated by

the use, in inverse order, of the corresponding portions of the right side,

arm, and hand, the little finger of the right hand signifying 19. The words

used were in each case the actual names of the parts touched; the same

word, for example, standing for 6 and 14; but they were never used in the

numerical sense unless accompanied by the proper gesture, and bear no

resemblance to the common numerals, which are but few in number. This

method of counting is rapidly dying out among the natives of the island,

and is at the present time used only by old people.[18] Variations on this

most unusual custom have been found to exist in others of the neighbouring

islands, but none were exactly similar to it. One is also reminded by it of

a custom[19] which has for centuries prevailed among bargainers in the

East, of signifying numbers by touching the joints of each other's fingers

under a cloth. Every joint has a special signification; and the entire

system is undoubtedly a development from finger counting. The buyer or

seller will by this method express 6 or 60 by stretching out the thumb and

little finger and closing the rest of the fingers. The addition of the

fourth finger to the two thus used signifies 7 or 70; and so on. "It is

said that between two brokers settling a price by thus snipping with the

fingers, cleverness in bargaining, offering a little more, hesitating,

expressing an obstinate refusal to go further, etc., are as clearly

indicated as though the bargaining were being carried on in words.

The place occupied, in the intellectual development of man, by finger

counting and by the many other artificial methods of reckoning,--pebbles,

shells, knots, the abacus, etc.,--seems to be this: The abstract processes

of addition, subtraction, multiplication, division, and even counting

itself, present to the mind a certain degree of difficulty. To assist in

overcoming that difficulty, these artificial aids are called in; and, among

savages of a low degree of development, like the Australians, they make

counting possible. A little higher in the intellectual scale, among the

American Indians, for example, they are employed merely as an artificial

aid to what could be done by mental effort alone. Finally, among

semi-civilized and civilized peoples, the same processes are retained, and

form a part of the daily life of almost every person who has to do with

counting, reckoning, or keeping tally in any manner whatever. They are no

longer necessary, but they are so convenient and so useful that

civilization can never dispense with them. The use of the abacus, in the

form of the ordinary numeral frame, has increased greatly within the past

few years; and the time may come when the abacus in its proper form will

again find in civilized countries a use as common as that of five centuries

ago.

In the elaborate calculating machines of the present, such as are used by

life insurance actuaries and others having difficult computations to make,

we have the extreme of development in the direction of artificial aid to

reckoning. But instead of appearing merely as an extraneous aid to a

defective intelligence, it now presents itself as a machine so complex that

a high degree of intellectual power is required for the mere grasp of its

construction and method of working.

The Number Concept: Its Origin and Development · 第 1 / 7 章