169.--A TANGRAM PARADOX.

Many pastimes of great antiquity, such as chess, have so developed and

changed down the centuries that their original inventors would scarcely

recognize them. This is not the case with Tangrams, a recreation that

appears to be at least four thousand years old, that has apparently

never been dormant, and that has not been altered or "improved upon"

since the legendary Chinaman Tan first cut out the seven pieces shown in

Diagram I. If you mark the point B, midway between A and C, on one side

of a square of any size, and D, midway between C and E, on an adjoining

side, the direction of the cuts is too obvious to need further

explanation. Every design in this article is built up from the seven

pieces of blackened cardboard. It will at once be understood that the

possible combinations are infinite.

[Illustration]

The late Mr. Sam Loyd, of New York, who published a small book of very

ingenious designs, possessed the manuscripts of the late Mr. Challenor,

who made a long and close study of Tangrams. This gentleman, it is said,

records that there were originally seven books of Tangrams, compiled in

China two thousand years before the Christian era. These books are so

rare that, after forty years' residence in the country, he only

succeeded in seeing perfect copies of the first and seventh volumes with

fragments of the second. Portions of one of the books, printed in gold

leaf upon parchment, were found in Peking by an English soldier and sold

for three hundred pounds.

A few years ago a little book came into my possession, from the library

of the late Lewis Carroll, entitled _The Fashionable Chinese Puzzle_. It

contains three hundred and twenty-three Tangram designs, mostly

nondescript geometrical figures, to be constructed from the seven

pieces. It was "Published by J. and E. Wallis, 42 Skinner Street, and J.

Wallis, Jun., Marine Library, Sidmouth" (South Devon). There is no date,

but the following note fixes the time of publication pretty closely:

"This ingenious contrivance has for some time past been the favourite

amusement of the ex-Emperor Napoleon, who, being now in a debilitated

state and living very retired, passes many hours a day in thus

exercising his patience and ingenuity." The reader will find, as did the

great exile, that much amusement, not wholly uninstructive, may be

derived from forming the designs of others. He will find many of the

illustrations to this article quite easy to build up, and some rather

difficult. Every picture may thus be regarded as a puzzle.

But it is another pastime altogether to create new and original designs

of a pictorial character, and it is surprising what extraordinary scope

the Tangrams afford for producing pictures of real life--angular and

often grotesque, it is true, but full of character. I give an example of

a recumbent figure (2) that is particularly graceful, and only needs

some slight reduction of its angularities to produce an entirely

satisfactory outline.

As I have referred to the author of _Alice in Wonderland_, I give also

my designs of the March Hare (3) and the Hatter (4). I also give an

attempt at Napoleon (5), and a very excellent Red Indian with his Squaw

by Mr. Loyd (6 and 7). A large number of other designs will be found in

an article by me in _The Strand Magazine_ for November, 1908.

[Illustration: 2]

[Illustration: 3]

[Illustration: 4]

On the appearance of this magazine article, the late Sir James Murray,

the eminent philologist, tried, with that amazing industry that

characterized all his work, to trace the word "tangram" to its source.

At length he wrote as follows:--"One of my sons is a professor in the

Anglo-Chinese college at Tientsin. Through him, his colleagues, and his

students, I was able to make inquiries as to the alleged Tan among

Chinese scholars. Our Chinese professor here (Oxford) also took an

interest in the matter and obtained information from the secretary of

the Chinese Legation in London, who is a very eminent representative of

the Chinese literati."

[Illustration: 5]

"The result has been to show that the man Tan, the god Tan, and the

'Book of Tan' are entirely unknown to Chinese literature, history, or

tradition. By most of the learned men the name, or allegation of the

existence, of these had never been heard of. The puzzle is, of course,

well known. It is called in Chinese _ch'i ch'iao t'u_; literally,

'seven-ingenious-plan' or 'ingenious-puzzle figure of seven pieces.' No

name approaching 'tangram,' or even 'tan,' occurs in Chinese, and the

only suggestions for the latter were the Chinese _t'an_, 'to extend'; or

_t'ang_, Cantonese dialect for 'Chinese.' It was suggested that probably

some American or Englishman who knew a little Chinese or Cantonese,

wanting a name for the puzzle, might concoct one out of one of these

words and the European ending 'gram.' I should say the name 'tangram'

was probably invented by an American some little time before 1864 and

after 1847, but I cannot find it in print before the 1864 edition of

Webster. I have therefore had to deal very shortly with the word in the

dictionary, telling what it is applied to and what conjectures or

guesses have been made at the name, and giving a few quotations, one

from your own article, which has enabled me to make more of the subject

than I could otherwise have done."

[Illustration: 6]

[Illustration: 7]

Several correspondents have informed me that they possess, or had

possessed, specimens of the old Chinese books. An American gentleman

writes to me as follows:--"I have in my possession a book made of tissue

paper, printed in black (with a Chinese inscription on the front page),

containing over three hundred designs, which belongs to the box of

'tangrams,' which I also own. The blocks are seven in number, made of

mother-of-pearl, highly polished and finely engraved on either side.

These are contained in a rosewood box 2+1/8 in. square. My great uncle,

----, was one of the first missionaries to visit China. This box and

book, along with quite a collection of other relics, were sent to my

grandfather and descended to myself."

My correspondent kindly supplied me with rubbings of the Tangrams, from

which it is clear that they are cut in the exact proportions that I have

indicated. I reproduce the Chinese inscription (8) for this reason. The

owner of the book informs me that he has submitted it to a number of

Chinamen in the United States and offered as much as a dollar for a

translation. But they all steadfastly refused to read the words,

offering the lame excuse that the inscription is Japanese. Natives of

Japan, however, insist that it is Chinese. Is there something occult and

esoteric about Tangrams, that it is so difficult to lift the veil?

Perhaps this page will come under the eye of some reader acquainted with

the Chinese language, who will supply the required translation, which

may, or may not, throw a little light on this curious question.

[Illustration: 8]

By using several sets of Tangrams at the same time we may construct more

ambitious pictures. I was advised by a friend not to send my picture, "A

Game of Billiards" (9), to the Academy. He assured me that it would not

be accepted because the "judges are so hide-bound by convention."

Perhaps he was right, and it will be more appreciated by

Post-impressionists and Cubists. The players are considering a very

delicate stroke at the top of the table. Of course, the two men, the

table, and the clock are formed from four sets of Tangrams. My second

picture is named "The Orchestra" (10), and it was designed for the

decoration of a large hall of music. Here we have the conductor, the

pianist, the fat little cornet-player, the left-handed player of the

double-bass, whose attitude is life-like, though he does stand at an

unusual distance from his instrument, and the drummer-boy, with his

imposing music-stand. The dog at the back of the pianoforte is not

howling: he is an appreciative listener.

[Illustration: 9]

[Illustration: 10]

One remarkable thing about these Tangram pictures is that they suggest

to the imagination such a lot that is not really there. Who, for

example, can look for a few minutes at Lady Belinda (11) and the Dutch

girl (12) without soon feeling the haughty expression in the one case

and the arch look in the other? Then look again at the stork (13), and

see how it is suggested to the mind that the leg is actually much more

slender than any one of the pieces employed. It is really an optical

illusion. Again, notice in the case of the yacht (14) how, by leaving

that little angular point at the top, a complete mast is suggested. If

you place your Tangrams together on white paper so that they do not

quite touch one another, in some cases the effect is improved by the

white lines; in other cases it is almost destroyed.

[Illustration: 11]

[Illustration: 12]

Finally, I give an example from the many curious paradoxes that one

happens upon in manipulating Tangrams. I show designs of two dignified

individuals (15 and 16) who appear to be exactly alike, except for the

fact that one has a foot and the other has not. Now, both of these

figures are made from the same seven Tangrams. Where does the second man

get his foot from?

[Illustration: 13]

[Illustration: 14]

[Illustration: 15]

[Illustration: 16]

Amusements in Mathematics · 第 197 / 970 题