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[Illustration]
PRIVATELY PRINTED OPUSCULA
ISSUED TO MEMBERS OF
THE SETTE OF ODD VOLUMES.
No. XXX.
Y^E MAGICK MIRROUR OF OLD JAPAN.
[Illustration]
[Illustration: YE MAGICK MIRROUR OF OLD JAPAN]
Ye Magick Mirrour of
Old Japan
BY
SILVANUS P. THOMPSON, D.SC., F.R.S.
_Magnetizer_ to the Sette of
Odd Volumes
A DISCOURSE DELIVERED AT A MEETING OF THE
SETTE HOLDEN AT LIMMER’S HOTEL, ON
FRIDAY, DECEMBER 2, 1892
[Illustration]
LONDON
Imprinted for the Author at the Chiswick
Press; and to be had of no Booksellers
CI[mirrored C] I[mirrored C] CCC XC III
Night’s Robe to-night with Orient Sorcery gleams--
Say: “Magick Mirrour!” murmur: “Old Japan!”
Each Sound’s a Spell, each Word a Talisman,
And we but Dreamers in a World of Dreams.
_J. T._
[Illustration]
DEDICATED TO
THE UNITED SETTE
BY
THEIR
_MAGNETIZER_.
[Illustration]
This Edition is limited to 97 copies, and is
imprinted for private circulation only.
No.
Presented unto
______________
by
______________
[Illustration]
[Illustration: PLATE I.]
[Illustration]
Y^E MAGICK MIRROUR OF OLD JAPAN.
In old Japan the mirror occupies a peculiarly important place.
Travellers in that land of strange arts and quaint customs tell us of
mirror-worship as one of its forms of primitive religion. In old Japan
the mirror is not, as in our Western civilization, a mere article of
furniture, an accessory of the toilet, or a means for covering up the
otherwise indecorate breadth of wall above a mantel-piece. One finds
the mirror in Japan surrounded with pomp and circumstance on every
hand. It is prominent amongst the symbolic objects that constitute
the imperial regalia of the Shogun. One sees it depicted in Japanese
pictures of the infernal regions. In the temples of the old Shinto
religion, precious old mirrors are enshrined in costly arks, only to be
exhibited on the occasion of some great ceremony. Innumerable mirrors,
some of them of old date, but mostly of modern manufacture, are to be
found hung upon the walls of the Shinto temples. There they have been
deposited as votive offerings by women who had perhaps nought else so
precious to offer. As the Japanese warrior offers as a votive gift
to the temple his cherished sword, so the Japanese lady bestows her
treasured mirror. There they hang in thousands, swords and mirrors,
side by side, thank-offerings to the gods. In the scant furniture of
the Japanese _ménage_, the mirror, reposing in its place upon the
lady’s toilet-table, forms the one significant object; the central
feature to suit which all the rest is subordinated. The mirror enters
into the myths of the Japanese race: it is the emblem of light, or
the sun, and of the divine right of the dynasty. In the trousseau of
the bride the mirror is the most precious object--her one cherished
possession. The first-made mirror--or the one held to be such in the
estimation of the Japanese, and venerated accordingly--is enshrined
in the great sacred twin-palace at Isé, the holy spot to which pious
pilgrims turn their steps with devoted zeal. Its origin is related in
the famous myth of the sun-goddess, Amaterasu oho-mi-kami, who, on one
occasion, withdrew offended to a rocky cavern, leaving the world in
darkness. From this retreat she was enticed by the other gods, after
many curious artifices had been tried, by their successful making of
a mirror, in which seeing her face reflected, she was impelled by
jealousy and curiosity to venture forth. This mirror was fashioned
by the Vulcan of the Shinto Olympus to imitate the sun, being in
shape a disk with eight rays. In modern Japanese heraldry the sun, as
blazoned upon the national flag, is a red orb with sixteen red rays,
not pointed as in European heraldry, but widening out to the margin
of the flag. Some hold that the Japanese imperial crest, the _kiku_,
which resembles a flower with sixteen petals joined and rounded at
the outer extremities, and issuing from a small central disk, is also
a blazon of the sun; others hold it to represent the chrysanthemum.
In Japanese pictures of the sun-goddess myth, the mirror is always
represented as of the eight-point form. Tradition states that the
flaw still to be seen in its surface was caused by a blow it received
when the gods thrust it into the half-opened doorway of the rocky
cavern as the sun-goddess peeped out. The standard version of the
entire myth is to be found in a memoir on the Shinto Temples of Isé
by Mr. Ernest Satow, in the second volume of the “Transactions of the
Asiatic Society of Japan” (1873-74). In the British Museum, in Dr.
Anderson’s collection of Japanese drawings, No. 1905, there is a silk
roll painted in colours, depicting the scene outside the cavern. It is
without signature or seal, and the artist is unknown. A further myth
narrates the subsequent history of the mirror. It was handed by the
sun-goddess to her grandson Nini-gi no mikoto when he descended from
heaven to subdue the earth, along with the sacred sword and the sacred
seal-stone (the three sacred treasures of the Japanese regalia), with
these words: “Look upon this mirror as my spirit: keep it in the same
house and on the same floor with yourself, and worship it as if you
were worshipping my actual presence.” Nini-gi no mikoto founded the
empire of Japan, and is worshipped as the first Shogun, all subsequent
sovereigns claiming divine right by descent from him. All mirrors in
Shinto temples, whether exposed to view or concealed in shrines or
arks, are imitations of this one, though some are regarded as being
representative of other secondary deities. At Isé, where the first
mirror is preserved, each mirror is enclosed in a box standing on a
stand, and covered with a cloth of silk. The mirror is itself wrapped
in a brocade bag, which is never opened or renewed, but which, when
nearly worn out, is enclosed in a new bag. Over the numerous wrappings
is a cage of wood with gold ornaments, draped with a curtain of coarse
silk. At festivals, when they open the shrines, all that can be seen is
the boxes with the coverings over them.
The mirror of old Japan is however a very different article from
that known in modern Europe as a mirror. European mirrors are made,
as everyone knows, of glass silvered at the back. Japanese mirrors
are invariably made of metal, the bronze employed being a compound
of copper and tin, with traces of antimony or lead.[1] The mirrors
preserved in the temples are not all of the eight-pointed form. Some
are simply circular, with a thick rim behind, and a central button
perforated to receive a suspending cord; the front being quite plane.
Others are oval, with feet, or with perforated handles at the upper
part for suspension. In the houses square mirrors are very rarely met
with, and these are mostly small. Those for the lady’s toilet table are
usually circular, from four to five inches across, without handles,
possessing a thick rim and a raised pattern on the back. Commonest of
all are the hand-mirrors, which are usually circular, from three to
eleven inches in diameter, with a metal handle covered with bamboo or
with brocade. They are usually slightly convex on the front surface,
which is brightly polished; while the back, which is for the most part
unpolished, exhibits a fine raised pattern. Often the raised ornament
consists of two distinct kinds. There is made in high relief, and
polished bright so as to stand out from the background, a simple bold
symbolic device, sometimes a Chinese character signifying “good-luck,”
or “long-life,” sometimes a family crest, such as the imperial _kiri_
(or Paullonia leaves and flowers), or a circlet, or three feathers
crossed, or the jagged peak of Fuji-yama, or the outline of a bird.
Ornament of the second kind is in low relief, and, though often
symbolic, consists of naturalistic representations of trees, flowers,
storks, bamboos, and the like. A group comprising pine-trees, storks,
and the hairy-tailed tortoise, all symbols of longevity or immortality,
is a favourite one. Sometimes the ornament consists exclusively of one
or other of these kinds; but more frequently both are present; the
unpolished low-relief work forming an artistic background for the crest
or the Chinese letters, which stand out polished. In passing it may be
remarked that the Japanese make use of Chinese characters in addition
to their own form of writing, just as we still use old English
black-letters for ornamental or distinctive purposes.
But the most interesting thing about Japanese mirrors--the one thing
that has made them famous and brought them to the notice of lovers
of the curious and the occult--is their reputed _magical_ property.
Oriental stories of magic mirrors have been current from the middle
ages, most of them wholly childish and absurd. But along with these
there have existed accounts, of a more reliable character, of mirrors
which are capable of reflecting, in a beam of light that falls on
their face, the pattern which they carry on their back. This singular
property is no myth, though the true explanation of the phenomenon was
long unknown. When first seen, the phenomenon is so startling that
it seems almost incredible. You take the mirror into your hand and
examine it. Its face is slightly convex, perfectly polished, unless
scratched by use or tarnished; and on looking into it you see only your
own image, or the objects about you--not a hint or trace of the raised
pattern at the back. Now hold up the mirror in direct sunlight, or
in the path of a powerful beam of light from some artificial source,
such as an electric lamp. It will reflect back the beam, and cast an
illuminated patch on the wall or floor, just as any other mirror will
do. But on examining this luminous patch you will at once observe--if
your mirror is a good one--that the salient features, and sometimes
even the fine details, of the pattern on the back are reproduced in
the light reflected from the front. Some dozens of Japanese mirrors,
most of them quite modern, have passed through the hands of the author
for optical examination. Some of these failed to show any magical
properties whatever. Others showed the property very well. Others
again, which showed nothing at first, were found capable of being
converted into magic mirrors by a course of treatment subsequently
discovered.
[Illustration: PLATE II.]
Down to about 1845 these mirrors were excessively rare in Europe,
though it is quite possible that they may have occasionally formed
part of the stock-in-trade of mediæval conjurors and magicians. Amidst
the mass of occult rubbish one may here and there discern statements
probably relating to the genuine phenomena exhibited by mirrors of the
class in question, having little or nothing in common with the visions
to be seen in crystal spheres, or beryls, or in pools of ink. Thus
Gaspard Schott, both in his “Physica Curiosa” and in his book on Magic,
refers to the Mirror of Pythagoras, in or on which he is said to have
written in blood the things which he wished to signify, and which, when
turned to the moon, displayed upon the disk of the moon, visibly to
one standing behind, the things so inscribed. The “disk of the moon”
here referred to may have been simply the luminous patch cast by the
reflected moonbeam.
Again, it is stated that the Italian historian, Muratori, makes two
references to magic mirrors, one in the possession of Bishop Bartolomeo
of Verona, who was murdered by Mastino della Scala in 1338; the other
found in the house of Cola di Rienzo (or Rienzi), which had upon its
back the word “Fiorone.” Not having been able to verify the statement
from literature available in the British Museum, I am in doubt about
the last case. It is much more likely that the mirror bore on its back
a large flower, than that it bore the word meaning a large flower.
Except for obscure references such as these, there is no record of
real magic mirrors prior to 1832. Yet a few did undoubtedly exist.
There were some in the collection of the royal family of Savoy at
Turin, which were later examined by Professor Govi. There was one
reputed to be magical in Berlin. The great Von Humboldt thought it
worth his while, in 1830, to bring this mirror to Paris to show it to
his _confrères_ of the _Académie des Sciences_; but having brought it,
found himself unable to show anything. In 1842 several mirrors were
brought from Nankin by Admiral Mouchez (commander of “La Favorite”), M.
Arosa, and M. Piou. One was in the possession of the Marquis La Grange
in 1847.
With the opening of Japan to the commercial world, in 1867, came the
export of mirrors amongst other articles of metal-work; amongst them
some that were of magic quality. One was displayed in 1876 in the
Loan Collection of Scientific Apparatus in the western galleries of
the South Kensington Museum. The official Catalogue (p. 927) thus
describes it: “983 c. Magic Mirror. [Exhibited by] Robert von Tarnow.
This mirror is a curiosity, and consists of a brass concave disc with
finely polished surface. At the reverse rough side there are several
Arabic (_sic_) characters in relief. By exposing the polished surface
to the rays of the sun in such a way that they reflect them on the
wall, the Arabic figures of the reverse side of the disc become plainly
visible in the reflected light on the wall.” It was this mirror which,
in the following year, the present writer had in mind when, writing
in “Nature,” he proposed that an investigation should be made into
the strange optical property so exhibited. Happily at that time his
friend Professor W. E. Ayrton was resident in Japan as Professor in the
Imperial College of Engineering at Tokio, and he and his colleague,
Professor Perry, at once engaged in an exhaustive research on the
subject, in the course of which they not only examined some hundreds
of mirrors, but also acquainted themselves on the actual spot with
the methods of manufacture, which until then were entirely unknown,
or misunderstood. A year or two later, after the publication of the
researches of Ayrton and Perry, other researches of an entirely
confirmatory character were published in France by M. Bertin. In fact,
the scientific investigations may be sharply divided into four periods.
(_i._) 1832. Elementary guesses by Brewster and Prinsep, the former of
whom ascribed the phenomenon to some supposed molecular changes in the
metal at the surface, due to a pattern having been stamped on the front
to imitate that on the back, and then ground off. The latter ascribed
it more correctly to differences of curvature of surface, but also fell
into the error of supposing the ornament to have been stamped.
(_ii._) 1844-1853. French investigations by Arago, Julien, Person, and
Maillard. Of these investigators Person gave the suggestion of the true
cause, namely, minute differences of curvature in the polished surface,
a circumstance which he proved by covering the mirror with a piece of
paper having a circular hole, about one centimetre in diameter, and
which, when moved about over the mirror (in sunlight), caused as a
reflected image a spot of light, the size of which varied from point
to point of the mirror. He also soldered a narrow slip of sheet metal
behind a polished daguerreotype plate, and found that when the latter
was slightly bent the image from the front showed a luminous line at
the corresponding place. Maillard later adopted Person’s theory, and
confirmed it by employing an optician to burnish on the lathe a piece
of metal which had raised markings on its back. He also noted that a
scratch on the mirror back gives a bright line in the image.
(_iii._) 1864-66. Investigations of Govi, in Italy, and his controversy
with Brewster thereon. Govi frankly adopted the views of Person, and
confirmed them by an experiment based on the mode adopted by the
constructors of reflecting telescopes for testing the accuracy of the
figure given by the grinding machinery to specula. He caused a magic
mirror to reflect upon a screen the image of a fine grating of lines,
ruled upon glass with a diamond, and placed close to a brilliant point
of light. By the distortions which the mirror produced in these lines
he found the whole reflecting surface to be minutely undulated over
with slight variations of curvature in complete correspondence with the
raised arabesques on the back. These undulations, he observed, escape
notice when one is looking into the face of the mirror because they are
so gentle, and are such that, to perceive them, we require organs that
are more delicate than our own. On the publication of this account, and
of a translation of it in the “Scientific Review” for 1865, Sir David
Brewster wrote to say how, in 1832, he had explained the phenomenon
as being due to differences of density or other quality of molecular
structure, or to fine scratches produced by trickery, and doubting
Govi’s explanation. He declared that similar phenomena had been
produced by stamping patterns into the face of brass and grinding them
down to be invisible on inspection. He considered the only way in which
they could be proved to be due to delicate differences of curvature was
either to show that they disappeared on re-surfacing the mirror with
a soft speculum-tool, or by taking an exact cast from the mirror, and
seeing whether this also had magic properties. Govi thus challenged, at
once disproved Brewster’s position, and established his own by showing
that the character of the image, white lines on dull ground, is changed
to that of dull lines on a brighter ground, by simply interposing in
front of the mirror a convex lens. This effect can only be produced
by difference of curvature of surface. Further, Govi performed
the following striking experiment. Taking a Japanese mirror which
ordinarily showed no magic effects, he heated it behind with a spirit
lamp, when at once it acquired magic properties. He further improvised
with a piece of daguerreotype plate, and a metal ring which he soldered
to the back at as low a temperature as possible, a mirror which showed
the same effects when, by heating, there arose an unequal expansion
between the thin and the thick parts.
[Illustration: PLATE III.]
(_iv._) 1878-80. Researches of Ayrton and Perry, and those of
Bertin, of Laurent, and of Muraoka. First, Ayrton and Perry set
about procuring mirrors from the shops in Japan, and found that the
vendors were in many cases wholly ignorant of the existence of the
magic property. Further, the mirror makers could not say how the
mirrors became magic, nor which of their mirrors were such; or they
gave explanations subsequently found false, declaring the effect to
be produced by application of an acid paste to etch the face prior
to polishing. The investigators then, having procured some good
mirrors, proceeded to test the various possible suggestions as to the
origin, such as the supposed difference of density, or of molecular
constitution, or the supposed inlaying of the face with inferior metal,
or to supposed concealed scratches on the surface, or, finally, to
differences of curvature. By simple experiments in which bright light
was caused successively to fall upon the mirror in diverging, parallel,
or converging beams, it was demonstrated beyond question that the
last-named cause was the true one. The whole phenomenon is explained
if once it could be established that the surface over the thick
parts is flatter (less convex, or even actually slightly concave)
than the surface over the thin parts. Using a large convex lens to
converge sunlight that had been reflected from a mirror, they showed
that by merely altering the distance of the screen on which the image
was received they could make the image either positive or negative
at will; a result impossible on any other hypothesis than that of
differences of curvature of surface. This being established, they then
investigated the process of mirror manufacture, to ascertain how these
delicate inequalities of surface arise; and they found it to be due to
an accident, or incident, of manufacture. All the finished Japanese
mirrors may be observed to be slightly convex in the face. They are
cast in moulds, the surface of each half of which is quite flat save
for the ornament incised on the mould for the back. The following is
Ayrton and Perry’s description of the process of casting.
“The material used for making the mould is a mixture of a special kind
of clay (found near Tokio and Osaka), with water and straw-ash. Two
suitable slabs having been formed from this plastic compound with the
aid of wooden frames, a thick layer of half-liquid mixture of powdered
old crucibles, or of a fine powder called _to-no-ko_, made from a soft
kind of whetstone, is spread on them. The design for the back of the
mirror is then cut directly on one half of the mould, or a sketch drawn
on paper is first stuck on and used as a guide in cutting the design
in the clay. Sometimes, but rarely, the design is stamped in the clay
with a pattern wood-block cut in relief like the proposed back of the
mirror. After the design is complete, a rim of the same material as
that used in the construction of the mould, and having a thickness
equal to that desired for the mirror, is attached to one half of the
mould. The two halves are then dried in the smoke of a pine-tree fire,
pressed and tied together, and laid in the casting-box at an angle of
80° to the horizon, the half of the mould on which the design has been
cut being uppermost. Finally the molten speculum metal is run into a
number of moulds at the same time, which, when cold, are broken up, and
the castings removed. Mirrors cast in a mould, in which the design
has been cut by hand, are called _ichi mai buki_, ‘mould used once,’
and are regarded as artists’ proofs, as the design on the back is well
defined. To form subsequent moulds the two halves are pressed, when
the clay is wet, on an _ichi mai buki_ mirror, and the pattern is in
this way transferred, but the designs on the backs of the mirrors cast
in such moulds are not as clear as on an _ichi mai buki_ mirror, which
therefore sells for a much higher price.” Flaws in the face of the
casting are filled by inserting little balls of copper--giving rise,
perhaps, to the idea that inlaying was used to produce the illusions.
The handle is not cast along with the disk of the mirror, but is
attached afterwards. Mirror castings when they are removed from the
mould are roughly flat on the face, and need to be subjected to several
processes to finish their reflecting surfaces: during these processes
they acquire their characteristic convexity and their high polish. The
mirror is laid down on its back on a wooden board, and then scraped or
scratched with a rounded iron rod about a foot long, called a _megebo_
(“distorting rod”). The process of scoring over with the blunt tool
is called _mege_. After being scored all over with scratches in every
direction, it is found to be convex. Next the face is scraped with a
hand-scraping tool, then rubbed down with a whetstone, then polished
over with a piece of magnolia-charcoal; and lastly, when quite smooth,
the amalgam of tin and mercury is rubbed in with a stiff straw brush,
and polished off with soft paper. Thicker mirrors are sometimes pared
down with a knife to the convex shape: they seldom or never show magic
properties. The knife is also used to pare down any portion which in
the operation _mege_ may have become too convex. The convexity is
tested from time to time by applying a concave wooden form. Professor
Ayrton was of opinion that the magic properties were conferred during
the operation of scraping with the _megebo_, the thicker parts of the
mirror yielding less, and therefore being polished down more than
the thinner parts. He also noted that if the face was scored by the
_megebo_ with parallel lines in one direction only, the convexity
acquired was cylindrical. His conclusion was: “It appears then that
the magic of the Eastern mirror results from no subtle trick on the
part of the maker, from no inlaying of other metal, or hardening of
portions by stamping, but merely arises from the natural property
possessed by thin bronze of buckling under a bending stress, so as to
remain strained in the opposite direction after the stress is removed.
And this stress is applied partly by the ‘distorting rod,’ and partly
by the subsequent polishing, which, in an exactly similar way, tends to
make the thinner parts more convex than the thicker.” The researches
of Ayrton and Perry may be said to have determined once and for all
the main cause of the magic properties. No one has since disputed the
principal propositions of their memoir, though it is certain that
the differences of curvature may be produced in several varieties of
operation.
Bertin, who wrote two years later, confirmed the conclusions arrived
at, and repeated on other mirrors the experiments of Ayrton and Perry,
as well as those of Person and Govi. Finding that the distortions
produced by heating were particularly efficacious in bringing out
the magic qualities, he sought to imitate them mechanically, and,
with the aid of the optician Duboscq, constructed an apparatus for
conferring temporary convexity upon mirrors by mounting them against
an air-tight back, with a cavity behind into which air could be driven
by a force-pump. With this apparatus he examined the effects that are
produced by drilling cavities, cutting grooves, and etching depressions
in the backs of mirrors. Laurent, taking up this line of suggestions,
produced magic mirrors of thin glass, etched into patterns at the back,
and silvered on the front face. These, when mounted on an air-tight
back, could be made to show either positive or negative figures by
diminishing or increasing the pressure of the air behind the mirror by
means of a simple india-rubber pear attached by a flexible tube to an
aperture in the back; the pressure of the hand sufficing to bring out
the optical effects. Laurent further showed that by taking an ordinary
piece of mirror glass (patent plate glass silvered at the back) magic
effects could be produced by lightly pressing against the back hot
pieces of metal on which a raised pattern had been engraved. In this
case the portions of the mirror nearest in contact with the hot metal
became hotter than the other parts, and expanding more, set up minute
differences of curvature sufficient to concentrate the reflected rays
of light from the heated parts.
About the same time Mendenhall, then in Japan, made further
observations, which were communicated to the American Association for
the Advancement of Science at its meeting at Cincinnati. Mendenhall was
followed by two Japanese observers,--both trained in physical research
in Europe,--Goto and Muraoka, the latter of whom, while confirming the
main propositions that the effects are due to differences of convexity,
and that the convexity is acquired during the process of _mege_ or
scoring over with the _megebo_, gave some further details learned from
the mirror-makers of Tokio. He showed that any plate, if thin enough,
whether of bronze, brass, copper, lead, zinc, iron, or glass, acquires
the property of convexity on being scored over with scratches; and
he came to the conclusion that this surface-expansion on the scored
side of the metal arose from some sort of release of molecular
tension across the lines so scored. Like Ayrton, he held that this
production of convexity on the scored surface explained the phenomenon
that a scratch made by a file or pointed tool on the back causes a
corresponding bright line to be reflected from the face. In a second
article Muraoka sought to prove that the differences of curvature are
not really due to differences of pressure during the operations of
scoring and surfacing, but are due to the unequal rising-up of the
metal in the thick and thin parts when the surface is caused to expand
by scoring it over with scratches.
[Illustration: PLATE IV.]
In May, 1886, Professors Ayrton and Perry, having discovered that the
act of amalgamating with mercury the surface of a thick brass bar
produces a powerful expansion of the amalgamated surface and bends
the bar convexly, made the further suggestion that the employment by
the Japanese mirror-polishers of a mercury-amalgam might assist the
operation of the _megebo_ in producing the differences of curvature
between the thinner and thicker parts.
The author having from time to time picked up a number of Japanese
mirrors from dealers in oriental curiosities, and having repeated all
the researches enumerated above and added some others, is able to
demonstrate very completely the phenomena in question.
Plate I. depicts a mirror in the author’s possession, about 7 inches in
diameter, the back of which bears in high relief a crest in the form
of a bird (_hoho_). The casting has evidently been tooled up to give
greater sharpness, and the part in high relief has been ground and
polished. The pattern which this mirror casts from its face is shown
beside the mirror, both being photographically reproduced. This mirror
shows the pattern with sunlight, or with the light of the electric arc,
or with lime-light. It can also be shown to a few persons at a time by
means of the flame of a paraffin lamp twenty feet away, or even by the
light of an ordinary candle a couple of feet away. In the case of these
weaker sources of light the mirror must be held close to the white
screen or card upon which the image is to be received.
Plate II. is taken from a mirror upon which there is, in high relief,
polished, a crest consisting of the imperial _kiri_ within a circlet,
together with a landscape of storks and bamboos in lower relief. In
this case only the ornament in high relief produces any effect: and
it is interesting to notice that, whereas the circlet on the back is
a simple flat band, the circlet in the image (which is distorted in
consequence of a general distortion of the mirror face as a whole)
presents double lines. The author is disposed to think that the
ornament on the back must in this instance have been subjected to
polishing subsequently to the front face.
Plate III. represents a very thin mirror, about 9-1/4 inches in
diameter and not more than 0·04 inch thick in its thinnest parts. The
central character in high relief is surrounded with the seven precious
objects in lower relief. Most of these may be seen more or less
distinctly in the luminous pattern cast from the front.
Plate IV. is a rather smaller mirror, 6-7/8 inches in diameter, having
low-relief ornament only; yet of this almost every detail is visible
in the image as cast by electric light or sunlight.
Plate V. shows a mirror which has two Chinese characters in
high relief, polished, with a background made up of symbols of
longevity--pine-tree, two storks, and a hairy-tailed tortoise. But
though these are in almost as high relief as the polished letters, only
the former are to be distinguished in the image. Here again the author
conceives that the two letters have been polished down subsequently
to the face; the pattern of these parts having been thus, to a minute
degree, forced into the reflecting surface.
Plate VI. depicts a rectangular mirror, 15 inches high by 10-1/2 inches
wide, and weighing 5-1/2 lbs. It is the only one of this form that he
has seen or heard of; though smaller square mirrors of 3 to 4 inches in
the side are not infrequent. One of the latter, in his possession, an
old mirror covered at the back with Chinese characters, has no magic
qualities at all. The large rectangular mirror is slightly convex, but
more so in its longer direction than in its breadth. The bamboos in the
pattern, though not very highly raised, are in very sharp relief,
the mirror being, apparently, an _ichi mai buki_, or artist’s proof.
There are two raised lumps on the back, apparently the remains of the
parts where the metal was poured into the mould; and, curiously enough,
neither these nor the rims of the rocks in the foreground yield any
image, though they are more highly raised than any part of the bamboos.
[Illustration: PLATE V.]
To complete the proofs that the effects are due to differences of
curvature the author has made the following observations.
By holding a magic mirror very obliquely to the light one can discern
traces of the pattern in the face, especially if one is accustomed
to examine optical surfaces for small inequalities of curvature. For
example, on examining (at oblique reflection) in such a mirror the
image of a horizontal window-bar or of the roof-line of a house, one
sees the straight line slightly curved downwards out of the level
wherever the image is made from a slightly concave (or less convex)
part of the surface. Acting on this hint the author found that if one
chooses as an object to be viewed in a mirror a pattern of narrow
parallel straight lines, such as a finely-striped blind, the pattern
on the back of the mirror can be dimly seen in the face, resembling
that species of line-engraving, sometimes used for medallion portraits,
in which the whole picture is crossed by lines from side to side, the
lines being bent toward one another or widened out to give effects of
light and shade. Another variety of the same experiment is to place a
ruled diffraction-grating of 100 lines to the inch (ruled in a silvered
surface on glass) close to a bright light, and with a short-focus lens
project the lines upon a screen. Then interpose the magic mirror to
throw the luminous lines upon another screen, when they will be seen
with the usual magic image; the bright lines concentrating into the
bright parts and avoiding the darker parts of the luminous pattern.
By the use of the spherometer to measure the surface curvatures of the
mirror faces, it is easy to show that the surface of the magic mirrors
is actually less convex, or even slightly concave, over those parts
where the substance of the mirror is thick, as compared with those
parts where the mirror is thin. For example, the curvature of the
rectangular mirror, Plate VI., as measured from left to right over the
convex surface, is, on the average, about 0·2 dioptries (or its radius
of curvature is about 5 metres), but when measured at points over the
vertical bamboo stems, its curvature falls to less than 0·05 dioptrie,
and in some parts is absolutely flat, or even slightly concave.
Makers of mirrors and lenses for large telescopes are accustomed to
test the perfection of their figure by a process known as Foucault’s,
in which the observer, after allowing light to fall from a single
well-defined point upon the (concave) mirror at nearly normal
incidence, places his eye at the point where the reflected rays
converge to a focus, and then sees the whole surface of the mirror
uniformly bright, save only such spots as differ in curvature from the
rest. In the case of convex mirrors it is needful to interpose a large
auxiliary convex lens to reconcentrate the otherwise divergent beam.
Applying this method of investigation, the author finds that it is
quite easy in many cases to see in the front face the pattern that the
mirror bears on its back.
Lastly, the author has made one absolutely direct proof of the
inequalities of curvature of the front surface. He took the mirror
depicted in Plate I., and having taken a mould of its face in a
composition of gutta-percha, he deposited a firm layer of copper in
the mould by the electrotyping process. The type so made was silvered
and polished, when it was found to reflect from its face the image of
the bird that was on the back of the original mirror; the image was,
however, less regular than that from the mirror’s own face. Here, then,
was a magic mirror without any pattern on its back.
In repeating the experiments on heating, the author found a very
singular effect to be produced by warming (with a flame) the back of a
thin piece of mirror glass while it reflected from its face a grating
of luminous lines thrown upon it by a lamp as described above. As the
flame was passed rapidly across the back, the whole pattern appeared to
heave, as though a wave had passed along it.
[Illustration: PLATE VI.]
He was able also to reproduce writing in luminous lines on a screen
or wall by the following device. A piece of thin sheet lead (tea-chest
lead) was laid on a bed of blotting-paper; and upon this was written
with a common lead pencil any word desired, which therefore was
slightly indented into the lead. The sheet was then pressed lightly
against an ordinary piece of mirror glass and heated from behind by
pressing against it a disk of hot metal. The written letters touching
the back of the mirror warmed it, and made it curve at these parts.
Hence, placed in an appropriate divergent beam of light, it threw the
handwriting upon the wall.
Following the hint given by Bertin’s research upon the effect of
bending mirrors by air-pressure at the back, the author finds that a
similar effect is even more powerfully produced by simple mechanical
pressure. He took a mirror which, though it had an excellent reflecting
face and a well-raised pattern on the back, showed no magic properties,
and having clamped it in a wooden frame, he applied screw pressure
behind to force against the back a slightly convex piece of soft wood
covered with a pad of cloth. On turning the screw the mirror at once
became magic, and was found, even after the screw had been released,
to retain some part of its magic property. It was again distorted
by screw pressure, and while violently bent was heated to anneal it
somewhat. On removing the pressure it was found to retain permanently
all the qualities of a good magic mirror, though it is slightly more
convex than mirrors ordinarily are. Since then it has been found that
many mirrors which, when purchased, showed no magic properties, can be
converted into magic mirrors, some by application of screw pressure,
some by mere bending by hand over the knee, some by burnishing under
pressure the pattern at the back.
Engineers are so familiar with the circumstance that when metal
castings are rapidly cooled the internal parts are in a state of
strain, that they are not astonished to find that after a casting has
been surfaced accurately on one face the figure may alter slightly by
the mere release of internal strains in the slow annealing of time. It
is quite possible that this too occurs with Japanese mirrors, and that
some of them may acquire with the mere lapse of time magic qualities
that they do not show at first when newly polished.
There appears to be another species of magic mirror, of which few
examples are known, having the property of showing in the face a
pattern entirely different from that on the back. Three such are
mentioned by Ayrton, though it does not seem that he himself had
inspected any of them personally. One of these, which he states
to exist at Kamakura, the old capital of the former Shoguns, is a
religious mirror about four inches and one-fifth high, by three
and a half wide, held in great reverence. In the polished surface,
when looked at very obliquely, is seen the image of a Buddhist
priest. The pattern on the back is a rosary in high relief with a
branch of plum-blossom, and a crescent moon rising out of the sea
as a background. It is said that this optical effect is produced
by chemically etching the surface with an acid paste, and then
repolishing. Professor Ayrton, who had two mirrors made thus by a
Japanese mirror-maker, found that if the face of a mirror that had so
been etched was repolished until every trace of the marks disappeared
in direct or oblique vision, they then entirely disappeared also
from the image cast by the mirror in reflecting a beam of light upon
a screen. He greatly doubted whether chemical means could produce a
mirror possessed of true magic properties. The cause of the phenomena
of the Kamakura mirror and its congeners--should the facts be
established as narrated--therefore remains still to be explained.
Though in the case of the ordinary Japanese mirrors science completely
explains what would otherwise seem to be a most mysterious and
unaccountable phenomenon, the explanation itself involves a very
remarkable fact, namely, that there can exist such very delicate
and minute differences of curvature in the polished face as to be
practically invisible for ordinary purposes, and difficult even
of scientific detection, and yet that those minute differences in
curvature should be in such exact correspondence to the patterns on the
back as to reproduce those patterns in the reflected beams of light.
The facts seem so utterly unlikely _à priori_ to be true, that one can
only give full credence to them after the most searching scientific
demonstration. But is not this, after all, only another example of
the truism that when science explains away one mystery she does so by
establishing some truth that is itself still more mysterious?
[Illustration: _The Mirror of Kamakura._]
[Illustration: JAPANESE WOMAN DANCING, WITH MIRROR.
From a bronze plate (_modern_).]
[Illustration]
APPENDIX I.
BIBLIOGRAPHY OF THE MAGIC MIRROR.
PART I. REAL MAGIC MIRRORS.
BREWSTER, SIR DAVID. Account of a curious Chinese Mirror, etc.
_Philosophical Magazine_, vol. i., p. 438, 1832. See also
_Poggendorff’s Annalen_, xxvii., pp. 485-489, 1833. [Translation of
the preceding], and _Journal Franklin Institution_, vol. xv., p. 128,
1832.
PRINSEP, JAMES. On the Magic Mirror of Japan. _Journal of the Asiatic
Society of Bengal_, vol. i., p. 242, 1832 (1 plate).
ARAGO, F. [Showed at meeting of _Académie des Sciences_ (Paris), a
mirror brought from China by M. Arosa]. _Comptes Rendus_, xix., p.
234, 1844. [Bertin, see 31 below, says that this mirror was brought
by Admiral Mouchez from Nankin; not by M. Arosa.]
JULIEN, STANISLAS. Notice sur les miroirs magiques des Chinois et
leur fabrication. _Comptes Rendus_, xxiv., p. 999, June 7, 1847.
[This is a translation of a Chinese writer, Ou-tseu-hing (1260-1340),
who wrote on this subject in a Chinese Encyclopædia. Also showed
mirror belonging to La Grange.]
SÉGUIER. [A note following the preceding.] _Comptes Rendus_, xxiv.,
p. 1001, June 7, 1847.
PERSON. Observations faites sur un des miroirs chinois dits miroirs
magiques. _Comptes Rendus_, xxiv., p. 1110, June 21, 1847.
MAILLARD. Note sur la fabrication des miroirs magiques chinois.
_Comptes Rendus_, xxxix., pp. 178-180, 1853. [See also _Journal
Franklin Institution_, lvi., 281, 409, 1853.]
GOVI, G. Gli specchi magici dei Cinesi. _Notizia storica della R.
Accademia delle Scienze di Torino_, 1864-65, pp. 67-74.
GOVI, G. Chinese Magic Mirrors [a translation of the Italian memoir
of Nov. 20, 1864]. _The Scientific Review and Journal_ (London), vol.
i., April 1, 1865, p. 19.
GOVI, G. Nuove esperienze sugli specchi magici dei Cinesi. _Torino
Atti Accad. Sci._, ii., 1866-67, pp. 357-362 (1 plate). See also
_Torino Lavori Sci. Fis. Mat._, 1869, pp. 67-75.
BREWSTER, SIR D. Observation on the preceding paper [on Chinese Magic
Mirrors]. _The Scientific Review and Journal_, vol. i., April 1,
1865, p. 20.
PARNELL, J. Chinese Mirrors, _The Reader_, vol. vii., p. 233, March
3, 1866.
PEPPER, J. H. Cyclopædic Science Simplified (London, 1869, F. Warne
and Co.). A passage on Magic Mirrors on pp. 35-39, with 5 figures
[some copied from Prinsep].
JULIEN, STANISLAS, and CHAMPION, PAUL. Les industries anciennes
et modernes de l’empire Chinois (Paris, 1869), containing a short
article on Les miroirs magiques des Chinois, et leur fabrication.
(Quotation from the memoir of M. Julien of 1847, _supra_.)
SATOW, ERNEST. The Shiñ-tau Temples of Isé. _Transactions of the
Asiatic Society of Japan_, vol. i., 1874. Reprinted 1882, p. 101.
Gives, p. 114-119, an account of the myth of the sun-goddess, and of
the making of the first mirror. Also speaks of the use of mirrors in
the Shiñ-tau religion.
GEERTS, DR. Useful Metals and Metallurgy of the Japanese.
_Transactions of the Asiatic Society of Japan_, vol. iv., 1875-76, p.
39. [An article on the Japanese uses of Mercury. Appendix, p. 39-41,
on Mirrors.]
ATKINSON, R. W. (Professor of the Tokio Dai Gaku, or Imperial
University). Letter in _Nature_, May 24, 1877, vol. xvi., p. 62.
HIGHLEY, SAMUEL. Letter in _Nature_, June 14, 1877, vol. xvi., p. 132.
DARBISHIRE, R. D. Letter in _Nature_, June 21, 1877, vol. xvi., p.
142.
THOMPSON, SILVANUS P. Letter in _Nature_, June 28, 1877, vol. xvi.,
p. 163.
PARNELL, J. Letter in _Nature_, July 19, 1877, vol. xvi., p. 227.
MASSE, E. Miroirs Japonais. _Journal de Physique_, t. vi., p. 320,
1877.
STERNE, CARUS. Article on Japanese Mirrors in _Gartenlaube_, Jahrg.
xxv., 1877, No. 29, p. 487 (1 cut).
AYRTON, WILLIAM E., and PERRY, JOHN (Professors in the Imperial
College of Engineering, Tokio). The Magic Mirror of Japan, part i.
_Proceedings of the Royal Society of London_, No. 191, 1878, p.
127-148.
AYRTON, WILLIAM E. The Mirror of Japan and its Magic Quality.
_Journal of the Royal Institution_, vol. ix., p. 25, 1879, being a
Lecture delivered January 24, 1879. [See also _Nature_, vol. xix., p.
539-542, April 10, 1879, and _Chambers’s Journal_, vol. lvi., p. 591,
1879.]
AYRTON, WILLIAM E., and PERRY, JOHN. Sur les miroirs magiques du
Japon. [Translation of their paper of 1878, with cuts added.]
_Annales de Chimie et de Physique_, 5^e Série, xx. p. 110, 1880.
AYRTON, WILLIAM E. _La Nature_, 1880, May 1, p. 514. (Report of
Lecture given in Paris.)
GOVI, G. Les miroirs magiques des Chinois. _Annales de Chimie et de
Physique_, 5^e Série, xx., p. 99, 1880.
GOVI, G. Nouvelles expériences sur les miroirs magiques. _Annales de
Chimie et de Physique_, 5^e Série, xx., p. 106, 1880.
BERTIN, A., et DUBOSCQ, J. Production artificielle des miroirs
magiques. _Annales de Chimie et de Physique_, 5^e Série, t. xx., p.
143, 1880.
BERTIN, A. Note sur les miroirs magiques. _Journal de Physique_, tome
ix., pp. 401-407, 1880.
LAURENT, L. Miroirs magiques en verre argenté. _Journal de Physique_,
tome x., pp. 474-479, 1881; also _Comptes Rendus_, xcii., 21 février,
21 mars, et 4 avril, 1881, p. 412-413.
BERTIN, A. Les miroirs magiques. _Revue Scientifique_, vol. l., 1881,
p. 258-263. (Lecture to the Association Scientifique de France).
BERTIN, A. Etude sur les miroirs magiques. _Annales de Chimie et de
Physique_, 5^e Série, t. xxii., p. 472-513, 1881 (avec 1 planche).
MENDENHALL, T. C. _Proc. American Assoc. for Advancement of Science_
(Cincinnati, 1881), vol. xxx., p. 57.
PERSON. _Gakugeishirm_, No. 39, quoted by Muraoka; see _infra_.
GOTO, MAKITA. _Tokio-Gakugeisassi_, No. 22, p. 35, quoted by Muraoka;
see _infra_.
MURAOKA, HANICHI. Herstellung der japanesischen magischen
Spiegel, etc. _Wied. Annalen_, xxii., p. 246-252, 1884. (From
the _Tokio-Gakugeisassi_.) [See also _Mittheil. der Deutschen
Gesellschaft Ostasiens_, heft 31, 1884].
MURAOKA, HANICHI. Ueber den japanesischen magischen Spiegel. _Wied.
Annalen_, xxv., 138, 1885.
ANDERSON, WILLIAM, F.R.C.S. Description and Historical Catalogue of
a Collection of Japanese and Chinese Paintings in the British Museum
(London, 1886). (On P. 398, § 1905, is a description of a picture
representing the myth of the sun-goddess.)
AYRTON, WILLIAM E., and PERRY, JOHN. On the expansion produced by
Amalgamation. _Proc. Physical Society of London_, vol. viii., p.
88-9, 1886.
PART II. ALLEGED REFERENCES TO MAGIC MIRRORS.
(_i._) THE MIRROR OF PYTHAGORAS. The passage in question is in the
_Physica Curiosa_ of Gaspard Schottus (4to Edition, Herbipolis, 1667),
p. 538, referring to his own book on magic, and runs as follows:
“Ibidem mentionem fecimus speculi Pythagorae, in quo sanguine
dicitur scripsisse quae volebat significare, et eo ad Lunam obverso
commonstrasse res exaratas stanti a tergo in disco Lunae.”
The reference is to another passage on page 553 of Schottus’ _Magia
Divinatoria_ (Herbip., 1657-59, par. iv.), in the chapter De
Catoptromantia: