We present an illustration of one of the toys of the year. It consists
of a nickel-plated box some three inches in diameter. In the center of
the top projects the end of a spindle, and at one side is a lever. To
operate the toy this side projecting piece is pulled out, and one of the
triangular pieces of tin, to which paper figures are attached, is placed
in contact with the spindle in the top of the box. The dancers then
begin a lively waltz on the top of the box. The secret of operation is
not at first apparent, though it is evident that magnetism has something
to do with it. On opening the box the mystery is solved. The spindle is
of magnetized steel and extends through the top of the box, forming a
slight projection. It turns freely and carries a pinion and a metal
disk. The pinion is actuated by the projecting side piece through the
medium of a toothed sector. Motion is transmitted to the triangular
piece of tin carrying the dancers by the magnetized spindle, causing a
horizontal movement, and giving it a movement around its own axis.
Curved wires and a spiral, one side of which is colored, are also
provided, and they all move around the pin at a lively rate, producing
novel effects.
[Illustration: THE DANCERS.]
AN ANCIENT COUNTERPART OF A MODERN TOY.
[Illustration: FIG. 1.--A TOY OF THE TWELFTH CENTURY.]
The very curious engraving which we reproduce herewith (Fig. 1) shows
once again that, as regards manners and the details of life, there is
nothing new under the sun. Every one has seen in the show windows of
toy-dealers a plaything called the “wrestlers,” and which consists of
two little weighted and jointed figures that are set in motion by a taut
string. At every tension of the latter these two little figures move
about, go through the motions of wrestling, and sometimes fall on top of
one another, much to the amusement of the spectator. Now, it is seven
hundred years ago that Herrade de Lansberg, abbess of Hohenbourg, in a
sort of encyclopædic compilation entitled “_Hortus Deliciarum_,” drew
the little combatants that are reproduced in Fig. 1. This valuable
MS., which was destroyed by Prussian shells in 1870, has been happily
saved from absolute annihilation by the copies of M. De Bastard, that
are at present preserved in the Cabinet of Prints of the National
Museum. This book is a sort of abstract, in figures, of Alsatian life in
the twelfth century, and games have not been forgotten therein. Herrade
de Lansberg’s little combatants are clad after the manner of the
warriors of those times, just as in our toy--the wrestlers--the figures
preserve the traditional costume of wrestlers at fairs. The two little
warriors wear a helmet with nasal; and a coat of mail, a buckler, and a
sword complete their equipment. Their feet, which were probably weighted
with lead, kept the puppets in a vertical position, and upon maneuvering
the strings an imitation of a sword contest was obtained.
[Illustration: FIG. 2.--A TOY OF 1897--THE WRESTLERS.]
It is probable that this toy was not a recent invention in the time of
Herrade, and that the abbess of Hohenbourg only put into her drawings a
costume that was already ancient.
NOVEL TOYS.
On any pleasant day may be found on lower Broadway and other down-town
thoroughfares venders who sell almost anything in the way of novelties.
Among these may be seen culinary implements, toilet articles, cheap
microscopes, magnifying glasses, and various toys. Nothing takes better
in the way of articles for this kind of trade than some new toy. Whether
a toy will probably have a good run can be determined by these venders
in a very short time. If it takes well, crowds gather around him, and he
does a thriving business, making money for himself as well as for the
inventor. If, however, the article is not wanted, the vender very soon
finds it out, and looks for other wares.
[Illustration: FIG. 1.--ACROBAT WITH MERCURY WEIGHT.]
Some of the toys are scientific, others are not. We give two examples of
scientific toys which have sold very well. They are similar in
character, and illustrate what shifting the center of gravity can do.
They are both acrobats. The one shown in Fig. 1, and designated
“McGinty,” and sometimes “Little Tommy,” consists of a paper figure
attached to a tube closed at both ends and inserted in paper disks which
are bent down on the tube, forming semicircular end pieces on which the
device may roll. A drop of mercury placed in the tube completes the toy.
When placed on a slightly inclined plane, with the tube parallel with
the surface, the mercury rolls to the lower end of the tube, causing
that end to preponderate. The lighter end, actuated by gravity, then
moves forward until it strikes the inclined surface, when the mercury
again rolls to the lower end and causes another half revolution, and so
on. This toy moves down the incline with a slow and stately movement.
[Illustration: FIG. 2.--TUMBLER.]
The toy shown in Fig. 2 is made upon the principle just described, but
the round ends of the figure furnish the rolling surfaces, and a bullet
is used for the weight instead of a globule of mercury, the body being
simply a straight paper tube with convex ends.
COLUMBUS’S EGG.
The accompanying engravings represent an object sold in the London
bazars. It is made of tin, is painted red, and is called “Christopher
Columbus’s Egg,” because those who do not know how it is constructed
cannot make it stand up on the projecting part situated at the base.
This egg, which it is impossible to open, is hollow, and contains a
leaden ball which causes it to fall over on its side, unless it (the
ball) is in the longer axis.
[Illustration: FIG. 1.--COLUMBUS’S EGG.]
The sections in Figs. 2 and 3 explain the construction, and show how the
ball is brought into the desired position to cause equilibrium.
Corresponding to the point where the halves of the egg are soldered
together, there is internally a partition that has the form of a
channel, of semicircular section, which runs around the tube, T. The
ball, B, when the egg is held vertically, is capable of revolving
around this tube, T, and as long as it remains in the channel will cause
the egg to fall every time the operator endeavors to make it stand on
its base, _c_. The egg can stand upright only on condition that the ball
be made to pass from the upper to the lower compartment, in which case
it will take the position, B′′′, at the base of the egg. This result is
reached as follows: The central tube contains, just beneath its upper
extremity, an aperture, B′′, that forms a communication between the two
compartments, and that is sufficiently large to allow the ball to pass
through. Two small guides start from the side of the egg, and follow the
contours of the partition up to the orifice in the central tube. On a
line with the orifice, and on the outside of the egg, there is a small
and scarcely visible point, _o_. If the egg be sufficiently inclined
toward this latter, as in Fig. 3, the ball will take the position, B′,
at the beginning of the guides leading to the orifice, B′′. If at this
moment the egg be gently turned back in the opposite direction, the
ball, being kept in the plane formed by the point, _o_, and the egg’s
axis, will run along the guides and drop through the orifice into the
lower compartment. When the egg is righted, the ball will take the
position, B′′′, at its base, and the egg will then stand upright. By
turning the egg upside down, the ball may be made to enter the upper
compartment again, and things will then be as before.
[Illustration: FIGS. 2 AND 3.--DETAILS OF CONSTRUCTION.]
With a little practice and skill, it is not even necessary to look for
the position of the point, _o_, and thus run the risk of showing the
uninitiated how the trick is done. On giving the egg a slight angular
motion, the hand will feel the passage of the ball over the slight
projection formed by the guides; the ball will naturally seat itself
upon the latter, and the double motion above mentioned will accomplish
the desired result. Effected in this way, and the hand being covered
with a handkerchief, the mode of operating will not be perceived by the
uninitiated spectator.
JACOB’S LADDER.
[Illustration: FIG. 1.--JACOB’S LADDER.]
[Illustration: FIG. 2.--CONNECTIONS OF JACOB’S LADDER.]
The simple toy illustrated in the annexed engraving is very illusive in
action. When the upper block is grasped by the edges, as shown in Fig.
1, and turned so as to lift the second block in the series to the same
height, the upper end of the second block falls into an inverted
position, and appears to pass downward on the other members of the
series, first upon one side of the ladder and then upon the other, until
it reaches the bottom. This effect is only apparent, as the second block
in reality only falls back to its original position in the series, but
in the operation it becomes reversed; what was before the lower end
becoming the upper end, the front having exchanged places with the back.
This change of position of the second member brings it parallel with the
third block, which is then released, and the third member drops over on
the fourth, when the fifth block is released, and so on throughout the
entire series.
In Fig. 2 are shown the three upper blocks of the series, 1, 2, and 3,
and their connecting tapes, the blocks being represented as transparent
and separated from each other a short distance to show the arrangement
of the connections. Block 1 has attached to it three tapes, _a_, _b_,
_b_. The tape, _a_, is attached to the face of the block at the center,
at the upper end, and extends over the rounded end of this block and
under the rounded end of block 2. The tapes, _b_, _b_, are attached to
the face of block 1, extending downward, under the lower end of this
block, and upward, over the upper end of block 2. The tape, _a_, which
is attached to the center of the upper face of block 2, extends over the
end of this block, downward underneath the block, and over the upper end
of block 3, where it is secured. This arrangement of tapes is observed
throughout the entire series.
In Fig. 2, block 2 is represented as falling away from block 1. When
block 2 reaches block 3, the tape, _a_, will be parallel with the face
of block 3, and the latter will be free to fall in a right-handed
direction, in the same manner as block 2 is falling in a left-handed
direction. When block 3 is parallel with block 4, the fourth block will
fall over in the left-handed direction.
The blocks, which are of pine, are each of 3-5/8 inches long, 2-3/8
inches wide, and 1/4 inch thick. The tapes, which are each 4-3/4 inches
long and 3/16 wide, are fastened at the ends to the blocks by means of
glue and by a small tack driven through each end of the tape, as shown.
A NOVEL TOY.
The annexed engraving represents an amusing toy recently sold on the
streets of New York. It is not particularly scientific, but it shows how
a device having little novelty finds sale in places traversed by the
multitude.
It consists of the figure of a Japanese in sitting posture, representing
the “Mikado.” In his right hand he holds a Japanese umbrella, and in his
left a fan. The umbrella is provided with a little reel at the top. The
stick of the umbrella in this case is formed of a tube which is held by
the hand of the Mikado, and a spindle attached to the umbrella top and
passing through the tube, with its lower end resting upon a beveled
wheel journaled within the figure. The beveled wheel carries a crank pin
working in a slotted arm that extends through the side of the figure and
grasps a fan, as shown in Fig. 2. When a cord is wound around the reel
at the top of the umbrella, and drawn off after the manner of top
spinning, the umbrella spins, giving a rotary motion to the beveled
wheel, and the crank pin projecting from the wheel imparts an
oscillating motion to the arm carrying the fan. The umbrella, being
slightly out of balance, gives a vibratory motion to the figure, which
causes it to rock slightly and turn upon its support.
[Illustration: THE “MIKADO,” A NEW TOY.]
A TOY CART.
[Illustration: POLLARD’S TOY CART.]
This simple toy for the diversion of children has been patented by Mr.
Paxton Pollard, a deaf-mute printer, of No. 89 Main Street, Norfolk, Va.
When the cart is drawn along, either forward or backward, the figures
are caused to bend or bow simultaneously; and at the same time, by the
compression and escape of air through drum-like pedestals beneath the
figures in the cart body, a whistling or squawking noise is made. The
figures may be of any desired grotesque shape, formed of paper or other
suitable material, and in each is a spiral spring normally holding the
images upright. The pedestals, of which a sectional view is shown in the
small figure, have each an upper and lower head and a covering of thin
skin or something similar, and in each is a coil spring, while in each
upper head is a small opening covered by a thin metallic tongue arranged
to vibrate rapidly on the passage of air through the opening. The upper
portions of the two figures are connected by a transverse rod, and this
rod is centrally connected by cord or rod with a crank in the central
portion of the axle, whereby the figures are made to bend or bow as the
cart is drawn along.
THE PHONOGRAPHIC DOLL.
[Illustration: THE PHONOGRAPHIC DOLL.]
One of the novelties which were introduced a few years ago was the
talking doll. This interesting toy consisted of a good-sized doll which
secreted a working phonograph. The doll’s body is made of tin, and the
interior thereof is filled with mechanism very much like that of the
commercial phonograph, but, of course, much more simple and
inexpensive. The cylinder of the phonograph of the talking doll is
mounted on a sleeve which slides upon the shaft, the sleeve being
screw-threaded so as to cause the cylinder to move lengthwise of the
shaft. A key is provided by which the cylinder may be thrown out of
engagement with the segmental nut, and a spiral spring is provided for
returning the cylinder to the point of starting. The cylinder carries a
ring of wax-like material upon which is recorded the speech or song to
be repeated by the doll. Upon the same shaft with the record cylinder
there is a large pulley which carries a belt for driving the flywheel
shaft at the lower part of the phonographic apparatus. The key is fitted
to the main shaft, by which the phonographic cylinder is rotated, and
the flywheel tends to maintain a uniform speed.
[Illustration: MECHANISM OF THE PHONOGRAPHIC DOLL.]
[Illustration: MAKING PHONOGRAPHIC RECORDS.]
Above the record cylinder is arranged a diaphragm such as is used in the
regular phonograph, carrying a reproducing stylus, which is mounted on a
lever in the same manner as the regular phonograph. The funnel at the
top of the phonographic apparatus opens underneath the breast of the
doll, which is perforated to permit the sound to escape. By the simple
operation of turning the crank any child can make the doll say “Mary had
a little lamb,” “Jack and Jill,” or whatever it was, so to speak, taught
to say in the phonograph factory.
Our last engraving shows the manner of preparing the wax-like records
for the phonographic dolls. They are placed upon an instrument very much
like an ordinary phonograph, and into the mouth of which a girl speaks
the words to be repeated by the doll. A large number of these girls are
continually doing this work. Each one has a stall to herself, and the
jangle produced by a number of girls simultaneously repeating “Mary had
a little lamb,” “Jack and Jill,” “Little Bo-peep,” and other interesting
stories, is beyond description. These sounds united with the sounds of
the phonographs themselves when reproducing the stories make a veritable
pandemonium.
In passing through the works it is noticeable that order and system
reign in every department. Everything is done upon the American, or
“piece,” system. The tools and machinery here used are the finest
procurable. Every piece, without regard to its size or importance, is
carefully inspected by aid of standard gauges, so that when the parts
are brought together, no additional work is required to cause them to
act properly.
The works of the doll are to some extent adjustable, and any adjustment
necessary is effected in an extensive department in which the little
phonographs are received from the assembling-rooms. Here they receive
the finishing touches, and are passed on to another room where they are
placed in the bodies of the dolls. From this department the finished
dolls pass on to the packing-room, where they are carefully stored away
in boxes having on their labels the name of the story the doll is able
to repeat.
CHAPTER III.
MISCELLANEOUS TRICKS OF AN AMUSING NATURE.
INTERESTING TRICKS IN ELASTICITY.
[Illustration: SCIENTIFIC TRICKS WITH BILLIARD BALLS AND COINS.]
The clever trick with billiard balls shown in Figs. 1 and 2 depends for
its success on a truly scientific principle. A number of billiard balls
are placed in a row against the cushion of the table. The player asks
one of the spectators to name a certain number of balls to be pocketed
without any apparent disturbance of the others. Suppose the number to be
three. Then at the will of the player three balls separate from the
others and roll into the pocket. The number is perfectly controllable,
and when the hand of the player and one end of the row of balls is
covered, the trick appears mysterious. It is hardly less so when the
entire experiment is visible. The feat is accomplished by removing from
one end of the series as many balls as are to be projected from the
opposite end, and rolling them forward against the end of the row
remaining. An equal number of balls fly off from the opposite end of the
row and roll into the pocket. Three balls driven against one end of the
series will cause three to roll off, two will drive off two, one will
drive off one, and so on.
The principle of this trick is illustrated in the well-known classroom
experiment in which a series of contacting suspended balls of highly
elastic material are made to transmit a blow delivered on the first of
the series to the last ball of the series, so that the last ball will
fly off without any apparent disturbance of the other balls. In this
experiment, the first ball of the series is drawn back and allowed to
fall against the first one of those remaining in contact. The impact of
this ball will slightly flatten the ball with which it comes in contact,
and each ball in turn transmits its momentum to the next, and so on
through the entire series, the last of the series being thrown out as
indicated.
In the case of the experiment with the billiard balls it is found by
careful observation that separate blows are given to the series,
corresponding in number to the number of balls removed, so that while
the separation of the three balls at the end of the series is apparently
simultaneous, in reality they are separated one at a time.
In Fig. 3 is illustrated a method of repeating the experiment with coins
in lieu of balls. Dollars or half dollars may be used, and the effect is
produced by sliding the coins.
NOVEL PUZZLE.
Our engraving shows a single perforated piece of wood having the form of
a conventional heart, and in the perforation is inserted an arrow, also
formed of a single piece of wood, the barb and head being much larger
than the perforation in which the shank of the arrow is received. The
heart is made of one kind of wood and the arrow of another. The question
is, How did the arrow get into the heart? We have heard of the
philosopher who was unable to rightly place a horse collar; and we have
seen philosophers who could readily harness a horse, but who could not
explain how the arrow got into the heart.
The puzzle illustrated is one of many thousands distributed gratuitously
upon the streets of New York as an advertisement. The heart is of black
walnut and the arrow is of basswood. Now we fear that the secret is out;
for any one familiar with the properties of basswood knows that it may
be enormously compressed, after which it may be steamed and expanded to
its original volume. One end of the arrow was thus compressed, and in
its compressed state was passed through the aperture of the heart, after
which it was expanded. Advantage has been taken of this principle in
the manufacture of certain kinds of moldings. The portions of the wood
to be left in relief are first compressed or pushed down by suitable
dies below the general level of the board, then the board is planed down
to a level surface, and afterward steamed. The compressed portions of
the board are expanded by the steam, so that they stand out in relief.
[Illustration: A NOVEL PUZZLE.]
SIMPLE MATCH TRICK.
[Illustration: A SIMPLE MATCH TRICK.]
To lift three matches by means of one, it is necessary to make an
incision in the end of a match and insert the pointed end of a second
match into this incision. Place them on the table, with a third match
resting against them for a support, as shown at the left of the figure.
Then present a match to any one who may be looking on, and ask him to
raise the three together by means of the match in his hand.
The solution is given at the right of the figure.
Bear lightly against the two matches that are joined until the third
falls against the one held in the hand. Then raise it, and all three
will be lifted together. Although this trick, which we find described in
a French paper, “_Le Chercheur_,” is probably as ancient as the art of
making matches, our juvenile readers may find it of interest, and
possibly it may afford them a half hour’s amusement at recess time.
CRYSTALLIZED ORNAMENTS.
A beautiful ornament, which is very easily made, consists of a wooden
cross covered with canton flannel, with the nap side out, and
crystallized by immersion in a solution of alum. The nap retains the
crystals so that they are not readily loosened or detached. The flannel
should be attached to the wood by means of brass wire nails, and the
cross should be suspended in a solution formed by dissolving a pound of
alum in a gallon of warm water. The cross should be suspended in the
solution while it is still warm and allowed to remain in until the
solution cools, when it will be found covered with bright crystals.
[Illustration: FIG. 1.--GROTTO.]
Fig. 1 is a perspective view, and Fig. 2 a longitudinal section, of a
grotto formed by crystallizing alum in a box containing jagged points
covered with canton flannel, or wrapped about in various directions with
coarse thread or twine. The box may be of wood or metal. It should have
apertures in the top, ends, and sides. These apertures are stopped with
corks while the box is filled with solution. After the crystallization
the corks are removed, and the holes in the top, sides, and one end are
covered with colored glass, and over the front aperture is secured a
convex spectacle lens, having a focus about equal to the length of the
box. When the interior of the box is illuminated by a strong light
passing through the colored windows, the effect is fine.
The solution used in this case is the same as that given for the cross.
After the crystals are formed and the liquid is poured from the box, the
interior should be allowed to dry thoroughly before closing the
apertures.
[Illustration: FIG. 2.--SECTION OF GROTTO.]
MAGICAL APPARITION OF A DRAWING ON WHITE PAPER.
It is well known that the vapors of mercury are very diffusive in their
nature, and some quite singular experiments have been devised, based
upon this knowledge, and upon the fact that the salts of silver and the
chlorides of gold, platinum, iridium, and palladium are affected by
these mercurial vapors.
If any one, for instance, should write upon a sheet of white paper with
platinum chloride, no mark would be visible, as the liquid is quite
colorless. If, however, the same sheet of paper should be held over a
little mercury, the metal will be brought out on the paper in dark
tints. This magical apparition of a figure or drawing on a sheet of
paper which appears to be perfectly white is very astonishing to the
spectator.
[Illustration: MAGICAL APPARITION OF A DRAWING ON WHITE PAPER.]
Reversing the experiment, a no less marvelous result is obtained. At
first expose the drawing or writing to the gases of mercury; the lines
will become charged with mercury, and then by simply bringing the
drawing in contact with a sheet of paper previously sensitized with a
solution of platinum, the drawing will be reproduced, line for line, on
the white paper.
Drawings made in this way give a charming effect, the tones being very
soft and the lines distinct and clear.
MAGIC PORTRAITS.
An able chemist, C. Wideman, has recently devised a curiosity in the way
of engraving. It is a square piece of transparent glass in which
absolutely nothing can be seen, even on the closest examination. If the
glass be breathed upon, so as to cover its surface with moisture, a face
like that shown in the cut makes its appearance. As soon as the moisture
leaves the glass, the image disappears.
[Illustration: MAGIC PORTRAITS.]
A piece of glass is obtained similar to that used for making mirrors.
The glass may be transparent, tinned, or silvered; that makes no
difference as to the final result. Then a small quantity of fluorspar is
placed in a porcelain capsule and moistened with sufficient sulphuric
acid to make the proper chemical reaction to write with. With this
liquid and a quill pen the desired drawing or writing is executed on the
previously well-cleaned glass. In about five minutes, or ten at the
most, the glass is to be washed in common water and dried with a cloth.
The plate will then be ready, and it will only be necessary to breathe
upon it to see the figures that have thus been traced make their
appearance.
A little practice will show the exact time necessary to leave the fluid
lines on the glass. Too long a biting of the acid would be accompanied
by so deep an engraving of the glass that the lines would always be
perceptible, even on the dry glass.
A TRICK OPERA GLASS.
[Illustration: A TRICK OPERA GLASS.]
We present an engraving of a trick opera glass which may be new to some
of our readers, although the principle involved is very old. One tube of
the opera glass is constructed in the ordinary manner, being provided
with lenses, while the other tube is arranged to give a view of any
object at right angles to the line of vision of the normal tube, or
considerably to the rear of it. The trick tube has no eyepiece, and the
objective is done away with, a piece of japanned wood taking its place.
A portion of the tube and its leather cover is cut away, and a mirror
is inserted at an angle in the tube. When the observer wishes to use the
trick glass at short range, he covers up a portion of the opening in the
tube with his fingers, but at longer range this precaution would not be
necessary. The practical uses of the glass are apparent. Our engraving
shows a plan view of a theater, with the stage, boxes, and seats. The
gentleman in the box and the one on the right of the center aisle both
appear to be observing the actor on the stage, but in reality they are
observing the lady on the left of the center aisle. Of course each of
the gentlemen has his glasses turned a different way around.
A TOY BIRD THAT FLIES.
[Illustration: A TOY BIRD THAT EFFECTIVELY SIMULATES A BIRD FLYING.]
The naturalness and the easy movement of the wings of the little toy
bird shown in the accompanying illustration, as the operator pulls
gently on the end of the supporting string over which the bird moves, in
accordance with the movement of the wings, always attracts observers
when this toy is shown on the streets, as it has been by numerous
venders within a short time. The toy is one of the latest of the many
novelties which are constantly being exhibited by the wide-awake
salesmen in the streets of New York and other large cities, and in the
construction of some of which a surprising degree of skill and ingenuity
are displayed. The cord leading from the aperture below the mouth of
the bird is attached at its outer end to a hook in the wall or other
support, while its inner portion passes over an idler and around a
pulley, to which it is attached. This pulley is a little smaller than
another at its side, as shown in Fig. 2, both pulleys being fast on the
same shaft, and a cord from the larger pulley passes over an idler and
out rearwardly, having at its end a finger-piece, on which the operator
pulls in manipulating the toy. The cords are wound in opposite
directions on their pulleys, so that the unwinding of the cord from the
larger pulley, and the rotation of the same, winds up the cord on the
smaller pulley, and causes the bird to move forward on what seems to be
only a single length of cord, the backward movement taking place by
gravity when the pull on the string is released. The movement of the
wings is effected by a crank on each outer end of the pulley shaft, the
crank being pivotally connected with an extension of a member of the
inner one of two pairs of lazy tongs, and this member having also a
pivotal bearing on a crossbar which turns in bearings on the outer side
of the toy, just under where the wings are hinged to the body. The
larger pair of lazy tongs is pivotally connected to the outer portion of
the wing, giving a longer sweep thereto than to the inner portion, with
which the smaller lazy tongs are connected; and the pivotal connection
of the lazy tongs with the bearing in the crossbar gives an oscillatory
movement to the wings, which constitutes a very good simulation of the
natural movement of the wings of a bird in flight. A high degree of
mechanical skill is shown in the putting together of this little toy.
THE PLANCHETTE TABLE.
This curious toy was popular as far back as 1867. Marvelous tales were
told by the credulous about it, and even as distinguished scientists as
Professor Tyndall and Professor Faraday were drawn into controversies
concerning it. Many think there is some hidden secret in the
construction of the planchette table. All that is necessary is that it
should stand firmly and move readily on its legs. All that is needful is
a heart-shaped cedar board with two nicely turned metal legs carrying
well-oiled casters, and in the point of the board an aperture of
suitable size for the insertion of a lead pencil, which serves as the
third leg, and rests upon the paper. Many believe that humbug was
stamped over every movement of the planchette board, and that one or the
other of those whose hands bore upon it conspired with the little board
in the formulation of its reply. Certain it is that planchette has
performed some curious feats and has made for itself a position in the
world of mysteries.
Probably the most generally accepted explanation is that advanced by
Lewes and others, that although there is no intentional movement of the
hands of those who are subjecting planchette to the influence, still
there is, in spite of this, an unconscious pressure of the finger tips
upon the board, which directs the movement of the pencil. Nor does it
seem that such can be at all unlikely, for unconscious movement is by
no means an unusual phase of our existence. The somnambulist who nightly
takes a promenade from cellar to garret, or whose steps by chance have
led him to the border of a precipice, has as little knowledge of the
peril he has escaped, when the morning beams have awakened him, as
planchette is conscious of its movements. How often also in mercantile
pursuits do those who are accustomed to a certain routine perform it
unconsciously, and after the work has been finished would be unable to
tell you of many of the details of the work which custom has taught them
to perform correctly, even while in a state of abstraction. Much has
been said at times of planchette’s prophetic nature. Under the influence
of certain people of a highly nervous temperament, or having to a
certain extent the qualities of mediums, future events are said to be
foretold. Secrets of which the person touching planchette is in
ignorance have been divulged in a remarkable way, and many anecdotes
shrouding planchette in mystery are repeated and believed.
[Illustration: PLANCHETTE.]
Were the testimony, however, more universal, were planchette more
consistent, and were it more generally truthful and less given to
uttering remarkable sayings only occasionally, there would be more
reason for according it a place for thorough and systematic
investigation. Perhaps the day will come, when mesmerism is understood
and mind reading is more satisfactorily explained, in which there will
be occasion for looking upon planchette more seriously, and of regarding
it as a wonderful means of displaying a rational nervous action
independent of conscious mental cerebration.
JAPANESE MAGIC MIRRORS.
Mr. R. W. Atkinson, of the University of Tokio, Japan, communicates to
“Nature” the following interesting account of these curious mirrors:
“A short time ago a friend showed me a curious effect, which I had
previously heard of, but had never seen. The ladies of Japan use, in
making their toilet, a small round mirror about one-twelfth to
one-eighth of an inch in thickness, made of a kind of speculum metal,
brightly polished, and coated with mercury. At the back there are
usually various devices, Japanese or Chinese written characters, badges,
etc., standing out in strong relief, and brightly polished like the
front surface. Now, if the direct rays of the sun are allowed to fall
upon the front of the mirror, and are then reflected on a screen, in a
great many cases, though not in all, the figures at the back will appear
to shine through the substance of the mirror as bright lines upon a
moderately bright ground.
“I have since tried several mirrors as sold in the shops, and in most
cases the appearance described has been observed with more or less
distinctness.
[Illustration: JAPANESE MAGIC MIRROR.]
“I have been unable to find a satisfactory explanation of this fact, but
on considering the mode of manufacture I was led to suppose that the
pressure to which the mirror was subjected during polishing, and which
is greatest on the parts in relief, was concerned in the production of
the figures. On putting this to the test by rubbing the back of the
mirror with a blunt-pointed instrument, and permitting the rays of the
sun to be reflected from the front surface, a bright line appeared in
the image corresponding to the position of the part rubbed. This
experiment is quite easy to repeat; a scratch with a knife or with any
other hard body is sufficient. It would seem as if the pressure upon the
back during polishing caused some change in the reflecting surface
corresponding to the raised parts whereby the amount of light reflected
was greater; or supposing that of the light which falls upon the
surface, a part is absorbed and the rest reflected, those parts
corresponding to the raised portions on the back are altered by the
pressure in such a way that less is absorbed, and therefore a bright
image appears. This, of course, is not an explanation of the phenomenon,
but I put it forward as perhaps indicating the direction in which a true
explanation may be looked for.”
The following account of the manufacture of the Japanese mirrors is
taken from a paper by Dr. Geerts, read before the Asiatic Society of
Japan, and appearing in their “Transactions” for 1875-76, p. 39:
“For preparing the mold, which consists of two parts put together with
their concave surfaces, the workman first powders a kind of rough
plastic clay, and mixes this with levigated powder of a blackish
‘tuff-stone’ and a little charcoal powder and water, till the paste is
plastic and suitable for being molded. It is then roughly formed by the
aid of a wooden frame into square or round cakes; the surface of the
latter is covered with a levigated half-liquid mixture of powdered
‘_chamotte_’ (old crucibles which have served for melting bronze or
copper) and water. Thus well prepared, the blackish paste in the frame
receives the concave designs by the aid of woodcuts, cut in relief. The
parts of the mold are put together in the frame and dried. Several of
these flat molds are then placed in a melting box made of clay and
‘chamotte.’ This box has on the top an opening into which the liquid
bronze is poured after it has been melted in small fireproof clay
crucibles. The liquid metal naturally fills all openings inside the box,
and consequently also the cavities of the moulds. For mirrors of first
quality the following metal mixture is used in one of the largest mirror
foundries in Kioto:
Lead 5 parts.
Tin 15 „
Copper 80 „
---
100
“For mirrors of inferior quality are taken:
Lead 10 parts.
Natural sulphide of lead and antimony 10 „
Copper 80 „
---
100
“After being cooled, the melting box and molds are crushed and the
mirrors taken away. These are then cut, scoured, and filed until they
are roughly finished. They are then first polished with a polishing
powder called _to-no-ki_, which consists of the levigated powder of a
soft kind of whetstone (_to-ishi_) found in Yamato and many other
places. Secondly, they are polished with a piece of charcoal and water,
the charcoal of the wood _ho-no-ki_ (_Magnolia hypoleuca_) being
preferred as the best for the purpose. When the surfaces of the mirrors
are well polished they are covered with a layer of mercury amalgam
consisting of quicksilver, tin, and a little lead. The amalgam is
rubbed vigorously with a piece of soft leather, which manipulation must
be continued for a long time, until the excess of mercury is expelled
and the mirrors have a fine, bright reflecting surface.”
MAGIC MIRRORS.
The following article on magic mirrors by MM. Bertin and Dubosq outlines
several interesting experiments.
“The people of the Far East, the Chinese and the Japanese, in bygone
times were acquainted with metallic mirrors only; and even to-day they
make only these. They are made of speculum metal, of various forms and
sizes, but always portable. One of the faces is polished and always
slightly convex, so that its reflection gives images which are reduced
in size; the other face is plane or slightly concave, and always has
cast on it ornaments which are in relief. Among the many mirrors thus
constructed there are a few which possess a wonderful property: when a
beam of the sun’s light falls upon the polished surface and is reflected
on a white screen, we see in the disk of light thus formed the image of
the ornamentation which is on the back of the mirror. The Chinese have
long known of these mirrors and value them highly; they call them by a
name which signifies ‘mirrors which are permeable to the light.’ We, of
the West, call them ‘magic mirrors.’
“Very few persons had seen magic mirrors till Mr. Ayrton, professor of
the Polytechnic School at Yeddo, exhibited several which he had brought
with him from Japan, and he experimented with them as already mentioned.
“In the meantime I received a visit from M. Dybowski, my former pupil,
who had returned from Japan, where for two years he had been the
colleague of Professor Ayrton. He brought back with him as objects of
curiosity four _temple mirrors_, that is to say, antique mirrors; these
are far superior to those of modern production, for their manufacture
has been nearly abandoned by reason of the introduction of the silvered
mirrors of Europe. We tried them together; three were circular, and the
thinnest of them, which is a disk of 15.3 centimeters in diameter, was
found to be slightly magic.
“To try such a mirror we reflect a sunbeam from its polished surface to
a white cardboard about one meter distant. But to obtain the very best
effects we must illuminate the mirror with a diverging pencil of light;
this pencil is made still further divergent by reflection from the
mirror, because its reflecting surface is convex. We can now receive the
reflected rays on a screen at a greater distance, and we at once see
distinctly the magnified image of the ornamentation on the back of the
mirror. These raised designs appear on the screen in white on a dark
ground. The image thus made by our mirror was confused, because it was
not a good one; had it been properly made, the image would have been
sharply defined. I then knew of no means by which I could make it give
better effects.
“The means by which the mirror could have been improved were first
pointed out by M. Govi in the second of his two papers. It is a
consequence of the true theory of magic mirrors. The theory was not
reached at once. I proposed to M. Dubosq to associate himself with me in
order, first, to repeat the experiments of the learned Italian, Govi,
and then to study generally the interesting phenomena of magic mirrors,
in the hope of being able eventually to reproduce them in his workshops.
At first we had only at our disposal the mirror brought from Japan by M.
Dybowski, and which gave confused images with the reflected solar rays.
These images became very sharply defined when we had heated the back of
the mirror with a gas lamp, and it gave very magic effects.
[Illustration: THE MAGIC MIRROR.]
“We then made a mold and reproduced this mirror, not in Japanese bronze,
but in ordinary gun metal. The first copy was roughly worked on the
lathe, after the Japanese manner, in order to render it magical, but
this was broken. The second was worked carefully on an optical grinding
tool; the surface was then polished and nickel plated, but it was not
magical; it acquired this property in a high degree when it was heated,
and even retained traces of it after it had been repeatedly heated.
Several Japanese mirrors which we have procured have given analogous
results.
“We then engraved letters on the back of little rectangular Japanese
mirrors. On heating these the letters appeared in black in the reflected
image. When we cut lines around the design on the back of the mirror,
heat rendered them very magical, for the design stood out, framed in the
black lines which bordered the figures.
“Thus it is seen that heat is very efficacious in rendering mirrors
magical, but it is not without its inconveniences. First of all, it
injures the mirrors, which thus lose their polish, especially when they
have been amalgamated; also, the mirror is often not heated equally, and
the images are deformed. It occurred to us that the change of curvature
which was required could be obtained more uniformly by means of
pressure. M. Dubosq therefore constructed a shallow cylinder of metal,
closed at one end by the metallic mirror, and at the other by a flat
plate of brass, having in its center a stopcock which we could attach,
by means of a rubber tube, to a little hand pump. This pump could be
made either to condense or rarefy air. If the rubber tube was attached
to the pump, arranged as a condenser, a few strokes of the piston
sufficed to compress sufficiently the air in the shallow cylinder; the
mirror became more and more convex, the cone of reflected rays became
more and more open, and in the image on the screen the design on the
back of the mirror became more and more distinct. Our Japanese mirror
when thus treated gave very fine images, and the copy which we had made,
and which gave no result as ordinarily experimented with, now became a
magic mirror as perfect as any of those which Professor Ayrton had
exhibited before us. A mirror in brass, nickel plated, on whose back was
soldered tin-plate figures, around whose borders were cut lines, became
very magical by pressure, and gave the design on its back in light
surrounded by dark borders.
“This is what I call the _positive image_. We can also obtain the
_negative image_, or the inverse of the preceding one, by rarefying the
air in the shallow box. To do this we have only to attach the rubber
tube to the pump arranged as an ordinary air pump. On now working the
piston the air in the shallow box is rarefied; the mirror becomes
concave; the cone of the diverging reflected rays closes up; the image
of the design is reduced in size, changes its appearance, and becomes an
image of the design on the back of the mirror; but this now shows in
shade edged with bright borders.
“These experiments require an intense light. A jet of coal gas is
insufficient, but the oxyhydrogen light is sufficiently intense. We
intercept it with a screen perforated with a small hole, so that the
diverging pencil which falls on the mirror may not spread too much. The
mirror is mounted on the top of a column so that it can be made to face
in any required direction. The effects are most brilliant and the best
defined when we experiment with the rays of the sun. When we expose the
mirror to the beam of the _porte-lumière_ it is generally not entirely
covered by the light; in this case it is best to use a diverging beam,
obtained by means of a lens placed between the _porte-lumière_ and the
mirror.
“Thus we have seen that we can now make copies of the Japanese mirrors,
some of which may be magical, but all may be rendered so by making them
covers of the shallow box containing either compressed or rarefied air.
This pressure box and its mirror, made in the Japanese style, certainly
forms one of the most curious pieces of apparatus which is to be found
in the cabinet of physics.
“We shall not, however, stop here. One of these days, while our mirror
is magical under the influence of pressure, we will take a cast of its
surface, and then reproduce this by means of galvano-deposition. This
surface will have all the irregularities of that of the magic mirror,
and will produce by its reflected rays the image of a design which no
longer exists on its back.”
BOOK V.
_PHOTOGRAPHIC DIVERSIONS._
CHAPTER I.
TRICK PHOTOGRAPHY.
LAVATER’S APPARATUS FOR TAKING SILHOUETTES.
[Illustration: SPECIMENS OF SILHOUETTES OBTAINED BY LAVATER.]
This is not a photographic diversion, but it is so interesting and so
much of a historical curiosity that we reproduce it here. When first
introduced, the silhouette attracted the attention of the learned, and
was regarded as one of the wonders of the age. Lavater, in his
celebrated work on physiognomy, describes an accurate and convenient
machine for drawing silhouettes. The engraving is almost
self-explanatory. “The shadow,” says Lavater, “is projected upon a fine
paper, well oiled and dried, and placed behind a piece of plate glass
supported in a frame secured to the back of the chair. Behind this glass
the artist stands, and holding the frame with one hand, draws with the
other.” A candle was used to furnish the necessary light. The
proportions of the silhouette must be judged principally from the length
and breadth of the face; a correct and well-proportioned profile should
be equal in breadth and height. A horizontal line drawn from the point
of the nose to the back of the head (provided the head be erect) should
not exceed in length a perpendicular line which extends from the top of
the head to the junction of the chin and head. All of the forms which
deviate sensibly from this rule are so many anomalies. In support of
these observations Lavater gives a number of specimens of silhouettes,
and insists upon the conclusion which he deduces from their study. We
take a few examples of them. In No. 1 Lavater sees an upright soul, an
even temper, taste, and frankness; in No. 2 the contour of the nose
carries the infallible mark of a good temper; in No. 3 we have clearness
of judgment.
[Illustration: LAVATER’S APPARATUS FOR TAKING SILHOUETTES.]
PHOTOGRAPHY UPON A BLACK GROUND.
Some of the most interesting trick photographs are obtained by the use
of a black background. In brief, the process consists in limiting the
field of an objective so as to preserve intact for subsequent exposures
the unused portion of the sensitized plate, and to be able to obtain
upon the latter such combinations as may be desired of any number
whatever of successive poses. The annexed diagram shows the arrangements
which may be used. Nos. I. to III. are the ones most frequently used,
and No. IV. permits of taking a number of photographs analogous to the
one that we reproduce in our second engraving.
[Illustration: FIG. 1.--EXPLANATORY DIAGRAM.]
Where a kneeling girl is represented as a statuette upon a table, the
operator is seen in the rear, manipulating the rubber bulb which
controls the shutter. In Fig. 3 is shown a picture taken in open
daylight, using as a black background the opening of a large coach
house; as a screen, a piece of blackened cardboard was used, as is
shown, supported by a violin stand to the right of the figures. Now, if
we closely examine the child who, in front of the cart, is assisting
in the delivery of his own head, we shall find that it is traversed
vertically by a line of shadows, indicating that a slight veil was
produced at the first exposure upon all that portion of plate that was
exposed by the incompletely drawn shutter of the frame. If the plate had
been entirely exposed it would be difficult to suspect anything.
[Illustration: FIG. 2--COMPOSITE PHOTOGRAPH IN TWO POSES, AT DIFFERENT
DISTANCES, ON THE SAME PLATE.]
[Illustration: FIG. 3--GROUP IN OPEN AIR, IN TWO DIFFERENT POSES ON ONE
PLATE.]
[Illustration: FIG. 4.--FACSIMILE OF A COMPOSITE PHOTOGRAPH.]
[Illustration: FIG. 5.--A DECAPITATION.]
[Illustration: FIG. 6.--ANOTHER DECAPITATION.]
The apparatus for producing the composite photographs upon a black
background is very simple. A blackened piece of cardboard is provided
with an aperture nearly corresponding to the place preserved in the
definitive picture for the object, head, bust, etc., that one desires to
isolate. This screen is slid into the first fold of the bellows of the
camera, that is to say, very close to the sensitized plate, and at the
moment of focusing, the position of the apparatus is so regulated as to
make the image of the subject appear through the apertures in the screen
and in the proper position. This process is the most rapid and is the
surest. No reflection is any longer possible, and the preservation of
the plate is absolute. What is no less advantageous is the sharpness of
the outline, which permits of the most delicate junctions; such
sharpness is inversely proportioned to the distance that separated the
screen from the sensitized plate. We present a number of engravings of
photographs taken upon a black background.
[Illustration: FIG. 7.--THE HEAD IN THE WHEELBARROW.]
[Illustration: FIG. 8.--THE HEAD UPON A PLATE.]
[Illustration: FIG. 9.--THE SAWED-OFF HEAD.]
[Illustration: FIG. 10.--THE REDUCTION.]
Our next engraving represents a decapitation by means of a saber, and it
is taken by means of an exposure in which the head was placed upon a
block, the subject inclining forward upon his knees, and the diaphragm
occupying about two-thirds of the plate, completely masking the body up
to the neck. Then, without changing the position of the apparatus, the
diaphragm is placed on the other side in order to conceal the head, and
the body is photographed in the second position along with the person
representing the executioner. It would have been possible by a third
exposure to so arrange things as to make the executioner the decapitated
person. By the same process the following trick photographs are made.
[Illustration: FIG. 11.--MAN IN A BOTTLE.]
The sawed-off head is one of the best of these photographs. Fig. 10
gives the same individual photographed twice on two different scales.
This kind of reduction gives very astonishing results.
The most curious illusion of all is the one in which a man is seen
inside of a bottle. The individual represented was first photographed on
a sufficiently reduced scale to allow him to appear to enter the bottle.
The diaphragm was arranged around the subject. The bottle was then
photographed on a large scale, and the result is, the man is seen in the
bottle.
SPIRIT PHOTOGRAPHY.[15]
[15] From “Photographic Amusements,” by Walter E. Woodbury. New York,
1896. The Scovill & Adams Co., publishers.
Many years ago, in the old wet-collodion days, a well-known photographer
was one day surprised by the visitation of a spirit. The apparition did
not make its appearance during the nocturnal hours, as is, we have been
given to understand, the custom of these ladies and gentlemen from the
other world, but, strangely enough, in broad daylight; and not by his
bedside to disturb his peaceful slumber, but upon the photograph he was
in the act of producing. Had this gentleman been of that soft-brained
kind, so easily gulled by the professional spiritualist, it is possible
that he would not have done what he did, which was to make a thorough
and scientific examination as to the probable cause of the phenomenon.
The case was this: A gentleman sitter had been taken in the usual manner
upon a collodion plate. Upon taking a positive print from the negative,
he was surprised to find a dim white figure of a lady apparently
hovering over the unconscious sitter. Upon examination of the negative,
the image of the figure was also visible, but not so plainly as in the
positive. The explanation of the whole matter was soon made easy. In
those days glass was not so cheap as at present, and all new or spoiled
negatives were cleaned off and freshly prepared with collodion for
further use. In this case the glass had previously supported the
negative image of a lady dressed in white. Some chemical action had
evidently taken place between the image and the glass itself, turning
the latter slightly yellow in some parts. This faint yellow image,
although hardly visible in the negative, had, being of a non-actinic
color, given quite a distinct image in the positive. The case was not an
isolated one, as these spirit photographs, as they were called, often
made their appearance when old negatives were cleaned and the glass used
again. The precise action producing the image has never, we think, been
satisfactorily explained. It could often be made more distinct by
breathing on the glass. We do not know if any enterprising humbug ever
took advantage of this method of producing spirit photographs to extort
money from the unwary, but about ten years ago a work was published,
entitled “Chronicles of the Photographs of Spiritual Beings and
Phenomena Invisible to the Material Eye,” by a Miss Houghton. In this a
number of reproductions of photographs of “spirits” were given with a
detailed explanation of how they were obtained and the difficulties
attending their production, the “spirits” being apparently of very
independent natures, only making their appearance when they felt so
inclined. It is quite possible that a person entirely ignorant of
photographic methods might be led into the belief that they were
actually photographic images of the dead, but we fear that the book is
hardly well enough written to deceive the experienced photographer. At
certain and most unfortunate periods in the process employed, some of
the plates had a convenient habit of slipping into the washing tank and
there, according to the author, becoming utterly ruined; also we learn
that many were ruined by being accidentally smudged by the
photographer’s fingers. We should not, we fear, have a very high opinion
of an operator who was in the constant habit of “smudging” negatives
with his fingers so as to entirely spoil them, nor can we quite
understand what brand of plates was used that “got spoiled by falling
into the water.”
[Illustration: A “SPIRIT” PHOTOGRAPH.]
It is not difficult to explain how these pictures were produced. There
are quite a number of methods. With a weak-minded sitter, over whom the
operator had complete control, the matter would be in no wise a
difficult one. It would then only be necessary for the “spirit,”
suitably attired for the occasion, to appear for a few seconds behind
the sitter during the exposure and be taken slightly out of focus, so as
not to appear too corporeal.
If, however, the sitter be of another kind, anxious to discover how it
was done and on the alert for any deceptive practices, the method
described would be rather a risky one, as he might turn round suddenly
at an inconvenient moment and detect the _modus operandi_. In such a
case it sometimes becomes necessary to find some other method where it
would not be requisite for the “spirit” to make its appearance during
the presence of the sitter.
The ghostly image can be prepared upon the plate either before or after
the exposure of the sitter. The method is this: In a darkened room the
draped figure to represent the spirit is posed in a spirit-like attitude
(whatever that may be) in front of a dark background with a suitable
magnesium or other light arrangement thrown upon the figure, which is
then focused in the “naturalistic” style; or, better still, a fine piece
of muslin gauze is placed close to the lens, which gives a hazy,
indistinct appearance to the image. The exposure is made and the latent
image remains upon the sensitized plate, which is again used to
photograph the sitter. Upon developing we get the two images, the
“spirit” mixed up with the figure. The “spirit” should be as indistinct
as possible, as it will then be less easy for the subject to dispute the
statement that it is the spirit-form of his dead and gone relative. Some
amount of discretion in this part of the performance must be used, we
fancy, otherwise the same disaster might happen as did to a spiritualist
some little time ago.
[Illustration: SPIRIT PICTURE.]
An elderly gentleman had come for a séance, and, after some mysterious
maneuvers, the gentleman was informed that the spirit of his mother was
there. “Indeed!” replied the gentleman, somewhat astonished. “What does
she say?” “She says she will see you soon,” informed the medium. “You
are getting old now and must soon join her.” “Quite right,” replied the
old gentleman; “I’m going round to her house to tea to-night.”--Total
collapse of spiritualist.
[Illustration: SPIRIT PICTURE.]
Fluorescent substances, such as bisulphate of quinine, can also be
employed. This compound, although almost invisible to the eye,
photographs nearly black. If a white piece of paper be painted with the
substance, except on certain parts, the latter only will appear white in
the picture.
We hope that it will not be inferred that we desire to explain how to
deceive persons with regard to photographs of “spirits,” for this is not
so; we only hope that they will be made merely for amusement, and, if
possible, to expose persons who practice on the gullibility of
inexperienced persons.
[Illustration: PHOTOGRAPH OF “SPIRITS.”]
The engraving on page 436 is a reproduction of a “spirit” photograph
made by a photographer claiming to be a “spirit photographer,” and to
have the power to call these ladies and gentlemen from the “vasty
deep” and make them impress their image upon the sensitized plate by the
side of the portraits of their living relatives.
Fortunately, however, we were in this case able to expose the fraud. Mr.
W. M. Murray, a prominent member of the Society of Amateur Photographers
of New York, called our attention to the similarity between one of the
“spirit” images and a portrait painting by Sichel the artist.
[Illustration: PAINTING BY N. SICHEL.]
A reproduction of the picture is given herewith, and it will be seen at
once that the “spirit” image is copied from it.
In a recent number of “The Australian Photographic Journal” we read of
the following novel method of making so-called “spirit” photographs:
“Take a negative of any supposed ‘spirit’ that is to be represented, put
it in the printing frame with the film side out; lay on the glass side a
piece of platino-type paper with the sensitive side up; clamp in place
the back of the printing frame and expose to the sun for half a minute.
Now place in the printing frame the negative of another person to whom
the ‘spirit’ is to appear, and over it put the previously exposed sheet,
film side down; expose to the sun for two minutes until the image is
faintly seen, then develop in the usual way, and the blurred ‘spirit’
photograph will appear faintly to one side or directly behind the
distinct image. Sheets of paper with different ghost exposures can be
prepared beforehand.”
“Spirit” photographs might easily be made by means of Professor
Roentgen’s newly discovered process of impressing an image upon a
photographic dry-plate without uncovering the shutter. The process
would, however, entail considerable expense, and would necessitate the
use of so much costly apparatus that we will content ourselves with the
simple mention of the possibility.
ARTIFICIAL MIRAGE.
The mirage is a well-known natural phenomenon, especially in tropical
countries. Our engraving shows an interesting experiment which permits
of reproducing a mirage by photography. A very even plate of sheet iron
is taken and placed horizontally upon two supports. The plate is heated
very uniformly and sprinkled with sand. A small, painted Egyptian
landscape is arranged at one end of the plate, and the “eye” of the
photographic instrument is so placed that the visual ray may be said to
graze the plate. The mirage can be photographed as shown in our
engraving.
[Illustration: ARTIFICIAL REPRODUCTION AND PHOTOGRAPHING OF A MIRAGE.]
DUPLEX PHOTOGRAPHY.
The following very ingenious method is pointed out by M. H. Duc, of
Grenoble. It consists in making use of a special frame which, instead of
having a sliding shutter, is provided with two shutters that operate
like the leaves of a door. These shutters, B B (Fig. 1), pivot upon two
vertical axes, A A, whose upper extremities project from the frame so
that they can be maneuvered from the exterior. As the shutters must join
very accurately, M. Duc affixes asbestos paper to their edges. A sliding
steel plate, E D, permits of keeping the two shutters closed before and
after exposure. This is removed when the frame is in the camera.
[Illustration: FIG. 1.--PLATE FRAME.]
The ground glass is divided into two parts by a pencil line that exactly
tallies with the junction line of the shutters. The subject is focused
on one of the halves of the glass, and then the corresponding side of
the frame is unmasked. After exposure the model changes place, and then
the other side of the frame is opened.
[Illustration: FIG. 2--COPY OF A PHOTOGRAPH SHOWING THE SAME PERSON
THRICE REPEATED.]
The photograph reproduced in Fig. 2 was taken in this manner. It
contains three representations of the same person. The easel, stool, and
artist having been arranged, an image is taken on the left side of the
plate, then the painter moves his position to the right and a second
exposure is made. The portrait on the easel is that of the same person,
but was taken afterward on the positive by means of the negative and a
vignetter (Fig. 3).
[Illustration: FIG. 3.--VIGNETTER.]
The other photograph (Fig. 4) is likewise very curious, and was taken
with the same apparatus. A hat was fixed firmly to a head rest, and the
same person then glided under it and presented his two profiles.
[Illustration: FIG. 4.--COPY OF A PHOTOGRAPH GIVING TWO PROFILES OF THE
SAME PERSON.]
ILLUSIVE PHOTOGRAPHY.
The amusing examples of illusive photography which we show herewith are
due to Mr. Frank A. Gilmore, of Auburn, R. I. The camera is so arranged
that the pictures which are reproduced suggest the story of Dr. Jekyll
and Mr. Hyde. The porter with the sack and the gentleman who is about to
give him some money are one and the same person. The pedestrian is
walking with himself, and the fighter is prepared to annihilate himself.
The method of producing the illusion is very simple. A black-lined box
is fitted to the back of a “kodak” or any other camera; the front of the
box is closed by two doors. On opening one door a picture may be taken
on one side of the plate; on closing this door and opening the other,
the other half of the plate is ready for exposure. The subject poses in
one position and his photograph is taken with one door open, care being
taken to bring the figure within half of the area of the sensitized
plate. A good finder enables this detail to be attended to. Then one
door is closed and the other is opened, and the exposure of the other
half of the plate is accomplished. The plate holder is not removed
during the dual exposure. If possible, instantaneous pictures should be
taken, as time exposures are rather risky, involving danger of shaking
the camera, and the length of exposure may not be the same for both
sides of the plate. Our engravings were taken with an ordinary four by
five “kodak,” and the box was an ordinary cigar box cut down to fit, and
blackened inside.
[Illustration: ATTACHMENT TO KODAK FOR DUPLEX PHOTOGRAPHY.]
[Illustration: SHOWING TWO PHOTOGRAPHS OF SAME PERSON ON A SINGLE
NEGATIVE.]
[Illustration: OTHER ILLUSTRATIONS OF DUPLEX PHOTOGRAPHY.]
PHOTOGRAPHING A HUMAN HEAD UPON A TABLE.
The picture is made in the following way: A table is provided with a top
having a portion of it movable at B. The person whose head is to be
photographed sits in a chair underneath the table. The board is removed
to allow the person’s head to pass above the table. The board is again
placed in position on the table, and the closer the person’s neck fits
the hole in the table the better. The camera is arranged with a box, as
in the illusion we have just described; but in this case the camera is
turned so that the two doors, C and D, open up and down instead of
sideways. The camera is raised or lowered until the crack between the
two doors of the box is on a level with the edge of the table. The upper
door, C, in the box is opened wide, so as to expose to the sensitized
plate, when the shutter is worked, the head above the table, and all of
the objects within the range of the lens above the edge of the table.
[Illustration: PHOTOGRAPHING A HUMAN HEAD UPON A TABLE.]
[Illustration: DIAGRAM SHOWING APPARATUS.]
After making these arrangements an exposure is made, then the person
whose head has been photographed is no longer required. The top door, C,
is now closed, and the bottom door, D, is opened wide. By this means the
upper part of the plate is protected from a second exposure and leaves
the way clear to expose the lower, and as yet unexposed, part of the
plate. The shutter is again opened, and this time everything in range of
the lens below the edge of the table is photographed, and, of course,
does not show the person under the table. The illustration which we
give, as well as the diagram showing how it may be produced, are the
work of Mr. James Burt Smalley, of Bay City, Mich.
PHOTOGRAPHING A HEAD ON A PLATTER.
[Illustration: HEAD OF LADY PHOTOGRAPHED ON A PLATTER.]
We have already shown how a photograph may be made upon a table, and we
now show how one can easily take pictures of the same person in
different attitudes on one plate. This trick is performed by Mr. Frank
Gilmore, of Auburn, R. I. Pictures made in this manner seem extremely
puzzling, when in reality they are very simple to make. An ordinary
extension dining-table is used, the person to be photographed being
seated in an opening between the two ends of the table, caused by the
removal of a leaf. The tablecloth is then arranged so as to cover the
gap. If necessary, the table may be built up with boards so as to
support the cloth and other articles. To make the illusion complete, a
pan, cut away so that it may be conveniently placed around the neck, as
shown in our engraving, may be used. This gives the appearance in the
photograph of being an ordinary platter bearing the head of a living
person.
[Illustration: PAN CUT AWAY TO REPRESENT PLATTER.]
[Illustration: HOW THE PHOTOGRAPH IS MADE.]
PHOTOGRAPHING A CATASTROPHE.[16]
[16] From “Photographic Amusements,” by Walter E. Woodbury.
On this page we reproduce a curious photograph by M. Bracq, which
appeared some time ago in the “Photo Gazette.”
Despite all the terrible catastrophe which it represents, carrying
pictures along with him in his fall, the subject has not experienced the
least uneasiness, not even so much as will certainly be felt by our
readers at the sight of the tumble represented.
[Illustration: FIG. 1.--A CATASTROPHE.]
The mode of operating in this case is very simple, and we are indebted
to “_La Nature_” for the description of the method employed by M. Bracq.
The photographic apparatus being suspended at a few yards from the floor
of the room, in such a way as to render the ground-glass horizontal
(say, between the two sides of a double ladder--a combination that
permits of easy focusing and putting the plates in place), there is
spread upon the floor a piece of wallpaper, about six feet in length by
five feet in width, at the bottom of which a wainscot has been drawn. A
ladder, a few pictures, a statuette, and a bottle are so arranged as to
give an observer the illusion of the wall of a room--that of a
dining-room, for instance. A hammer, some nails, etc., are placed at the
proper points. Finally a five by two and one-half foot board, to which a
piece of carpet, a cardboard plate, etc., have been attached, is placed
under the foot of a chair, which then seems to rest upon this false
floor at right angles with that of the room.
Everything being ready, the operator lies down quietly in the midst of
these objects, assumes a frightened expression, and waits until the
shutter announces to him that he may leave his not very painful
position. This, evidently, is merely an example that our readers will be
able to modify and vary at their will.
[Illustration: FIG. 2.--ARRANGEMENT OF CAMERA.]
NEW TYPE OF PHOTOGRAPHIC PORTRAIT.
Our engraving shows a new type of photographic portrait which gives the
effect of a marble bust. The model is placed behind a hollow column or
thin pedestal of painted wood. If it is desired to represent a man in
classic costume, a helmet of white cardboard is placed upon the model’s
head, his hair and face is whitened with rice powder, and those portions
of the body it is desired to render visible are surrounded with white
flannel. The background should be formed of black velvet. After the
negative is developed, the figure that it is desired to preserve is cut
around with a penknife, and the arms and all the portions that are not
wanted are scratched out. The glass thus becomes transparent when the
scratching has been done, and in the positive the bust stands out from
the background.
[Illustration: FIG. 1.--A PHOTO BUST.]
[Illustration: FIG. 2.--HOW THE BUST IS MADE.]
A MULTIPLE PORTRAIT.
[Illustration: FIG. 1.--REPRODUCTION OF A PHOTOGRAPH OF A MULTIPLE
PLATE.]
[Illustration: FIG. 2.--DIAGRAM SHOWING THE ARRANGEMENT OF THE
APPARATUS.]
The portrait which we reproduce was taken by a photographer of
Constantinople, Mr. Baboudjian. The subject of the photograph is
represented a number of times, so that the whole presents the aspect of
a number of persons standing in a line. Two mirrors, A and B, are placed
parallel to each other, and are separated by an interval of about two
feet. In the narrow corridor thus formed he places the subject to be
photographed. One of the mirrors must be a little taller than the other,
and the apparatus is turned toward the shorter one and is slightly
inclined toward the floor. The mirrors are without frames. The result of
this arrangement is shown in our engraving, the same person being
represented a number of times. There is considerable difficulty in
lighting the subject properly.
MULTIPHOTOGRAPHY.
[Illustration: DIAGRAM OF THE PRODUCTION OF FIVE VIEWS OF ONE SUBJECT BY
MULTIPHOTOGRAPHY.]
[Illustration: GALLERY ARRANGED FOR MULTIPHOTOGRAPHY.]
The system of photography which we illustrate gives an excellent
opportunity for a great range in the art of posing; the instrument is
called the “multiphotograph.” If an image is placed in front of two
mirrors inclined to each other at an angle of ninety degrees, three
images will be produced in the mirror; at sixty degrees, five images
will be produced; at forty-five degrees, seven images; and if the
mirrors are parallel, theoretically, an infinite number of images will
result. In the process of the photography which we illustrate, advantage
is taken of this to produce at one exposure a number of different views
of the same subject. The person to be photographed sits with the back to
the instrument, while in front of the face are two mirrors set at the
desired angles to each other, the inner edges touching.
[Illustration: REPRODUCTION OF A MULTIPHOTOGRAPH.]
In the case illustrated, these mirrors are inclined at an angle of
seventy-two degrees; four images are produced. The exposure is made, and
on the negative appears not only the back view of the subject, but also
the four reflected images in profile and different three-quarter
positions.
The courses taken by the rays of light are determined by the law that
the angle of incidence is equal to the angle of reflection. In the
diagram the rays of light are traced in their course from the subject to
the mirror, and back and forth, giving a good idea of the relation of
the images to the subject and of the five images to the focal plane, the
virtual position of the images being further from the instrument than
the subject proper. We also give an engraving showing images of a
full-length figure.
[Illustration: IMAGES OF A FULL-LENGTH PORTRAIT.]
PINHOLE CAMERA.
We illustrate in the cut a camera for photography in which the _ne plus
ultra_ of simplicity may fairly be said to be attained. It is a little
tin box two inches in diameter and three-quarters deep from cover to
bottom. A hole was punched in the center of the cover, and over this a
piece of foil was secured by varnish. The foil was taken from a button
card. Small mother-of-pearl buttons are generally mounted on pieces of
pasteboard with this foil under them. Through the foil, where it
extended across the hole in the box cover, a hole was made with a No. 10
needle. The needle was pressed through until its point could be just
felt by the finger held against the opposite side of the foil. This made
an aperture one-sixtieth inch in diameter. The interior of the box was
blackened. A piece of Eastman’s “A” bromide paper, cut circular so as to
fit in the box, was placed in it against the bottom, and the cover put
on. This, of course, was done in the absence of actinic light. Then,
with an exposure of four minutes, at a distance of about ten feet from
the object, the negative shown in the sketch was taken. It was developed
with oxalate developer. Castor oil or vaseline was used to make it
transparent, so as to adapt it for printing from. The subject of the
negative was the old armory at Summit Hill, Mt. Jefferson, Pa.
[Illustration: PINHOLE CAMERA.]
As nothing special, neither paper, glass negative, nor developer, was
used, this process of pinhole photography deserves special mention. It
might often be of considerable use in emergencies that sometimes will
present themselves to the photographer.
The special novelty that presents itself is the use of paper instead of
glass for the negative, as paper can be cut to fit any size or shape of
box. The brand of paper employed is slow paper.
A PHOTOGRAPHIC NECKTIE.
[Illustration: FIGS. 1 AND 2.--PHOTOGRAPHIC NECKTIE--FRONT AND BACK
VIEW.]
This ingenious apparatus is a French invention. The general appearance
of the necktie is seen in our second engraving, the first figure showing
the back of it. The metallic camera is flat and very light, and is
hidden under the vest. The interior mechanism comprises six small frames
which are capable of passing in succession before the objective. These
frames each hold a sensitized plate or film. The necktie having been
adjusted, the shutter is set by a pull upon the button, A, which passes
under the vest. In order to change the plate it is necessary to turn
from left to right the button, B, which has been introduced into the
buttonhole of the vest and which simulates a button of that garment. The
frames are attached to a link chain, something like an ordinary bicycle
chain, which is operated by the button. In order to open the shutter it
is only necessary to press the rubber bulb, which may be placed in the
pocket. The shutter is tripped pneumatically by means of the bulb and
tube. In order to change the plates it is only necessary to turn the
small springs, G G G. The sensitized plates or films are put in the
frames, and the springs are turned back to their former position. The
lens is, of course, concealed in the scarf pin.
MAGIC PHOTOGRAPHS.
[Illustration: PHOTOGRAPHIC CIGAR HOLDER.]
[Illustration: DEVELOPING THE PHOTO.]
A recent novelty is a cigar or cigarette holder accompanied by a small
package of photographic paper about the size of a postage stamp. One of
these papers is placed in the interior of the holder, before an orifice
arranged for the purpose. The smoke of the tobacco, coming in contact
with it, develops a portrait or other subject. The process employed is
very simple and consists in preparing a small photograph on chloride of
silver paper. The paper can be purchased ready prepared. The prints are
fixed in a bath of sodium hyposulphite (eight to ten per cent.), without
having been toned with gold. They are then washed with great care in
order to free the fibres of the paper from every trace of the salt,
which would cause a yellowing of the print after it was finished. The
print is now taken and floated on a five per cent. bath of bichloride of
mercury. The images at first gradually fade and finally disappear
altogether. After the prints are thoroughly bleached, they are washed in
water and allowed to dry. In order to make the latent image appear, it
is only necessary to immerse the print in a weak five-per-cent. solution
of sulphite or hyposulphite of sodium. When the prints are to be
developed photographically, they are placed in the cigar holder so that
the lateral orifice in the holder will admit the smoke to the print. The
ammoniacal vapors contained in tobacco smoke possess, like sodium
hyposulphite, the property of coloring black the chloride of mercury
contained in the prepared paper.
AN ELECTRO-PHOTO DETECTIVE THIEF CATCHER.
[Illustration: FIG. 1.--THE PHOTO DETECTIVE.]
[Illustration: FIG. 2.--DETAILS OF THE PHOTO DETECTIVE APPARATUS.]
The device which we illustrate has been very successful in securing
photographs which have led to the identification of the perpetrators of
petty thefts. A cigar dealer of Toledo, Ohio, had for some time lost
cigars from his showcase, and the detectives were foiled in their
attempts to discover these thieves, so he had recourse to the proprietor
of the photographic apparatus shown in our engravings. The apparatus
was set up and arranged in working order. It was then left to do its
work. Early one morning two boys entered the place, opened the showcase,
and, in so doing, set in operation the apparatus, which made a permanent
record of their deed, and upon the evidence thus obtained they were sent
to prison. As the boys opened the case they closed an electric circuit
which released the camera shutter, and at the same instant operated the
flashlight apparatus. Our first engraving shows the photograph being
taken, and our second shows the mechanism. The side and end of the
camera are removed so as to show the mechanism. The camera is placed in
a box which is provided with a shutter operated by the spring seen at
the front of the box. The shutter is tripped by an electro-magnet. On
the top of the camera box is arranged another electro-magnet, and a
vertical spindle carrying at the top a roughened disk; the
electro-magnet being connected with a detent which engages an arm on the
vertical spindle. A match is placed in a spring-pressed holder which
rests against the roughened disk, and above the disc is supported a
flashlight. When the circuit is closed by tampering with the showcase,
the shutter of the camera is opened by the action of the magnet
connected with the escapement, and the detent magnet at the top of the
box is operated with the shutter. The detent is then released and allows
the vertical spindle to revolve, the power for the purpose being stored
in a volute spring connected with the spindle. The match is ignited, and
as the disk completes its revolution, the match projects through the
aperture and ignites the flashlight powder. All this occurs in a
fraction of a second, and as soon as the shutter is opened and closed
the image on the sensitive plate is prevented from being further acted
upon. To secure the closing of the shutter, the current which lets off
the igniting mechanism is taken through a fusible wire or strip located
in the flashlight chamber. When the flashlight powder burns, the wire or
coil is melted, the circuit is broken, and the shutter is released, so
as to close automatically. The effectiveness of the apparatus is clearly
proved by the work it has done. At the same time there seems to be no
good reason why the burglar could not smash the whole apparatus, thus
destroying all photographic record of the crime.
COMPOSITE PHOTOGRAPHY.
Composite photography consists in the fusion of a certain number of
individual portraits into a single one. This is effected by making the
objects which are to be photographed pass in succession before the
photographic apparatus, giving each of them a fraction of the long
exposure, equal to such exposure expressed in seconds and divided by the
number of the objects which are to be photographed. Composite
photography is interesting when applied to photographs of persons.
Theoretically this is what occurs: Features peculiar to each of the
portraits, not having been sufficiently exposed, do not take; and the
features common to all, having been given a proper exposure, alone leave
a visible trace, along the sensitized plate. Therefore, the result
obtained may be considered as the type of the race or the family, but,
of course, is only of limited value. Our engraving shows twelve
portraits, six men and six women, some of whom are quite young and some
middle-aged, as may be readily seen. An exposure was made in succession
of No. 1 to No. 12, that is to say, beginning with the youngest woman
and ending with the oldest man; and then from No. 12 to No. 1, that is
to say, in inverse order. A man and a woman were interposed, and the
experiment was renewed, preserving the same arrangement, but changing
the order of the subjects. The result remained constantly the same, as
may be readily seen by glancing at the four composites, A, B, C, and D,
of the engraving. Upon one side the type of six men (composite E) was
made, and on the other, of six women (composite F). Here the change
produced is very perceptible. It is always the same head; but while
before we had a being of indeterminate sex, we find here, with perfect
distinctness, a man on one side and a woman on the other. The
experimenter wished to see whether twelve other persons (six men and six
women), taken from the same population, would give a type analogous to
the first. As may be seen (composite G), there is a slight difference,
but the character of the head is the same, the difference existing
especially in the physiognomy. The same remark may be made as to the
composite H obtained from the six women of the preceding group joined
with the six women figured Nos. 1, 2, 3, 4, 5, 6, which alone gave the
composite F. This observation proves (what was to be foreseen) that the
more the number of subjects for each experiment is increased, the
greater will be the probability of obtaining the true type of the
population studied. On the contrary, when but three are taken, a great
risk will be run of generalizing too much. In this case, moreover, each
exposure is necessarily too long, since it consists of a third of the
normal exposure and is no longer the resultant of the three heads, but
their superposition. Hence the slightest increase in the length of one
of the three exposures assumes considerable importance.
[Illustration: COMPOSITE PHOTOGRAPHS.]
CHAPTER II.
CHRONOPHOTOGRAPHY.
Instantaneous photography has been of the greatest possible use to
science, especially that branch of it which has been termed
“chronophotography.” It is to the investigations of Mr. Muybridge and M.
Marey that we are indebted for the most valuable researches on the
subject. Chronophotography consists in taking a number of photographs of
any object at short and regular intervals of time. This is accomplished
in many ways, and results obtained are useful for many purposes. The
graphic method has been of great service in almost every branch of
science, and laborious statistics obtained by computation have been
replaced by diagrams in which the variation of a curve expresses in the
most striking manner the various phases of some patiently observed
phenomena. Furthermore, by the methods of modern science, a recording
apparatus has been devised which, working automatically, traces the
curves of such physical or physiological events which, by reason of
their slowness, feebleness, or their speed, would otherwise be
inaccessible to observation. The development of these methods of
analyzing movement by photography have enabled the researches of
physiological laboratories to become of the greatest possible value. The
matter in this chapter is very largely an abstract of M. Marey’s
researches, which were originally published in “_La Nature_,” and their
publication in the “Scientific American Supplement” extended over a
period of several years. Subsequent to this publication M. Marey wrote a
book called “_Le Mouvement_,” which has been translated by Mr. Eric
Pritchard under the title of “Movement.” It is published in the
International Scientific Series; and for a more extensive and scientific
treatment of the subject than we are able to give here, we refer our
readers to this excellent work. M. Marey describes the rudiments of
chronography by supposing we take a strip of paper which is made to
travel by clockwork at a uniform rate. A pen affixed above the paper
marks, as it rises and falls alternately, the various periods and
intervals. When the pen comes in contact with the paper it leaves a
record in the form of dashes of different lengths at varying intervals.
If the dashes should be equidistant it shows that the periods of contact
follow one another at equal intervals of time. Now, as it is known that
the speed at which the paper travels is so many inches or feet per
second, it is an easy matter to obtain an accurate measurement of the
duration of contact and of the intervals between. In brief, this is the
principle of chronography. Chronophotography is simply an amplification
of this system and has many advantages, rendering measurements possible
where the moving body is inaccessible. In other words, there need be no
material limit between the visible point and the sensitized plate.
Mr. Muybridge’s experiments on the gaits of the horse are famous. He
used a battery of cameras as shown in our first engraving. Some of the
results obtained are shown in Fig. 2.
[Illustration: FIG. 1.--ARRANGEMENTS ADOPTED BY MR. MUYBRIDGE IN HIS
EXPERIMENTS ON THE GAITS OF A HORSE.
On the left is the reflecting screen against which the animal appeared
_en silhouette_. On the right is the series of photographic apparatus,
of which each one took an image.]
[Illustration: FIG. 2.--TWELVE SUCCESSIVE PHOTOGRAPHS, BY MR. MUYBRIDGE,
OF A HORSE IN FULL GALLOP.
In the last figure the horse is shown standing still. The speed of the
horse was about 1,142 meters (3,746 feet) per minute.]
[Illustration: FIG. 3.--CHRONOPHOTOGRAPHIC TRAJECTORY OF A BRILLIANT
BALL THROWN ACROSS THE BLACK SCREEN.]
[Illustration: FIG. 4.--CHRONOPHOTOGRAPHIC APPARATUS PRODUCING UPON ONE
PLATE A SERIES OF PHOTOGRAPHS AT EQUAL INTERVALS OF TIME.
The apparatus is open and shows the position of the disk, with its
openings moving in front of the plate.]
In Mr. Muybridge’s arrangement, photographic instruments faced a white
screen before which passed an animal walking, trotting, or galloping. As
fast as the animal advanced, the shutters of the lenses opened and
permitted the taking of negatives of the animal. These were, of course,
different from each other, because they were taken in succession. They
therefore showed the animal in the various attitudes he assumed at
different instants during his passage across the field covered by the
instruments. The dazzling white light brought out _en silhouette_ the
body of the animal. Each shutter is actuated by a powerful spring; the
shutter is opened as the animal advances. Threads may be observed across
the road; the animal, breaking these threads one after the other, opens
the shutters. Mr. Muybridge varied his experiments most successfully. He
studied the gaits of different animals, and those of men in jumping,
vaulting, and in the handling of various utensils. But since this time
the progress of photographic chemistry has wonderfully increased the
sensibility of the plates, and at the present day more than mere
silhouettes of moving animals and men can be obtained. In a good light
full images with all desired relief can be obtained. For example, if an
athlete in motion is photographed, all of the muscles of the body are
perfectly traced in relief, indicating the parts taken by each of them
in the movement executed. The methods used by Mr. Muybridge would always
suffice to illustrate the successive phases of the displacement of the
members if they were taken at equal intervals of time, but the
arrangements adapted for bringing about the formation of the successive
phases cause irregularity in the extent of these intervals. The threads
give more or less before breaking; moreover, the progress of the horse
is not at an even rate of speed. Nevertheless, Mr. Muybridge endeavored
to develop from a series of images the trajectory of each leg of a
horse, but the curves obtained in these laborious attempts had not
sufficient precision. A very simple method enables us to obtain, with
perfect fidelity, the trajectory of a body in movement; it is the
photographing of this body in front of a black surface. If the
photographic apparatus is directed against a black screen, the objective
can be uncovered without effect on a sensitized plate, as it will
receive no light; but if a white ball strongly illuminated by the sun is
thrown across the plane of this screen, and parallel with it, its image
will be reproduced upon the plate, which will show the track of the ball
in its trajectory, just as the eye receives a momentary impression of
lines of fire when a lighted piece of charcoal is waved through the air
at night.
[Illustration: FIG. 5.--GENERAL VIEW OF THE PHYSIOLOGICAL STATION AT
PARIS.]
[Illustration: FIG. 6.--DARK CHAMBER ON WHEELS.]
[Illustration: FIG. 7.--INTERIOR ARRANGEMENT OF THE DARK CHAMBER.]
Fig. 3 shows the parabolic trajectory of a brilliant ball thrown across
the face of a dark screen; but it is discontinuous, as exposures were
only produced each fiftieth of a second on account of the number of the
openings and the speed of the rotation of the disk. This is only an
example which shows the almost limitless number of varieties of movement
which may be analyzed by chronophotography.
With ordinary shutters it would be difficult to obtain this quickness,
but the perforated disk which is used in chronophotography gradually
acquires a speed of rotation that may be very great. Fig. 4 shows the
arrangement of this disk by which a rotary movement is imparted by a
powerful gearing controlled by a regulator. As soon as the disk obtains
a speed of ten turns a second, the regulator maintains this speed with
perfect uniformity. The disk moves in front of the sensitized plate a
few millimeters only; then, knowing the angular value of each of the
openings, the period of exposure is easily deduced therefrom.
[Illustration: FIG. 8.--WALKING MAN, CLOTHED IN WHITE, PASSING ACROSS
THE FIELD.]
The condition most difficult of fulfillment is the absolute darkness of
the screen before which the photographs are taken. Little light as there
is, the screen might reflect upon this sensitized plate, during a single
exposure, small quantities of light, which would tend to fog the plate.
A wall painted with any black pigment, or even covered with black
velvet, exposed to the sun, reflects too much light for a plate to
withstand. The term “black screen” is used in a metaphorical sense. In
reality the work is done before a dark cavity, being in truth what is
known as “Chevreul’s black.” To obtain these favorable conditions, a
chamber nearly thirty-three feet deep and of equal breadth was
constructed; one face of this chamber was open, and restricted by
movable frames to the exact height necessary. The interior of the
chamber was completely blackened, the ground was coated with pitch, and
the back hung with black velvet.
[Illustration: FIG. 9.--INSTANTANEOUS PHOTOGRAPH OF A MAN JUMPING OVER
AN OBSTACLE.]
Before entering into a detail of the experiments, we shall point out the
general arrangement of the Physiological Station of Paris. Fig. 5 gives
a general view of the grounds and buildings.
On these grounds, which were laid out by the city of Paris as a nursery,
there is a circular road, thirteen feet wide, designed for the exercise
of horses, and, outside of this, a footpath for men. All around this
road there runs a telegraph line whose poles are spaced 164 feet apart.
Every time that a person walks in front of a pole a telegraphic signal
is given, and this is inscribed in one of the rooms of the principal
building. Further on we shall speak of this sort of automatic
inscription, by means of which we ascertain at every instant the speed
of the walker, the variations therein, and even the frequency of his
steps. In the center of the track there is a high post that carries a
mechanical drum which regulates the rhythm of the gait, and which is
actuated by a special telegraph line running from one of the rooms in
the large building, wherein the rhythm is regulated by a mechanical
interrupter.
From the center of the circle, likewise, there starts a small railway
upon which runs a car that forms a photographic chamber, from the
interior of which is taken a series of instantaneous images of the
horses or men whose gait we desire to analyze.
Fig. 6 represents the photographic chamber in which the experimenter
places himself. This chamber is mounted upon wheels, and runs upon a
railway in such a way that it can approach or move away from the screen
according to the objectives that are being used and to the size of the
images that it is desired to obtain. As a general thing, it is
advantageous to place the photographic apparatus quite far from the
screen, say about 164 feet. From this distance the angle at which the
subject whose image is being taken does not change much during the time
it takes to pass before the black screen. From the exterior of this
chamber are seen the red windows through which the operator can follow
the different motions that he is studying. To have the different acts
performed he gives his orders through a speaking trumpet. The front of
the chamber is removed in Fig. 6 in order to show a revolving disk
provided with a small window through which the light enters the
photographic objective intermittently. This disk is of large dimensions
(four and three-quarters feet in diameter), and the window in it
represents only one hundredth of its circumference. It follows from this
that if the disk makes ten revolutions per second, the duration of
lighting will be but _one thousandth of a second_. Motion is
communicated to the disk by a train of wheels which is wound up with a
winch and which is actuated by a weight of one hundred and fifty
kilograms placed behind the chamber. The motion of the disk is arrested
by a brake, and a bell maneuvered from the interior serves to give
orders to an aid either to set the disk in operation or to stop it.
Fig. 7 shows the inner arrangement of the chamber, a portion of one of
the sides being removed to show the photographic apparatus, A, placed
upon a bracket before the screen. This apparatus receives long and
narrow sensitized plates that exactly hold an entire image of the
screen. At B is the revolving disk which produces the intermittent
illuminations, and at D is a cut-off which is raised vertically at the
beginning of the experiment, and which is allowed to fall at the end so
as to allow light to enter only during the time that is strictly
necessary. E is a wide slit in front of the objective, for allowing the
latter to take in the field in which are occurring the motions that are
being studied.
The darkness that reigns in the rolling chamber permits of manipulating
the sensitized plates therein at ease, and of changing them at every new
experiment.
[Illustration: FIG. 10.--INSTANTANEOUS PHOTOGRAPH OF A MAN WALKING.]
[Illustration: FIG. 11.--MAN CLOTHED IN BLACK VELVET.
The axes of the limbs are traced by white cords; the joints carry white
buttons placed at the point of rotation. The head is covered by a helmet
of black velvet which completely hides it, and to which is affixed a
bright ball at the level of the ear.]
[Illustration: FIG. 12.--CHRONOPHOTOGRAPHIC IMAGES OF A RUNNER.
Below the figure is a scale whose divisions are 0.50 meter (19-7/10
inches) long, and serve to give the extent of the movements.]
Against the dark field just described, a man placed in full light,
naked, or clothed in white, gives a sharp image on the sensitized plate.
The results in running and jumping which are obtained by this means are
very satisfactory. For scientific purposes it is found that the results
are better if, instead of white clothing, the runner is clothed in
black velvet. By this means he becomes nearly invisible before the black
area. If white cords are attached to this costume, following the
direction of the axes of his limbs, and white buttons used for the
principal articulations, the white parts are reproduced and reobtained
on the sensitized plate in an almost unlimited number of positions.
[Illustration: FIG. 13.--OSCILLATIONS OF THE LEG OF A WALKING MAN.]
[Illustration: FIG. 14.--SUCCESSIVE POSITIONS OF THE LIMBS IN AN ELASTIC
JUMP UPON THE BALL OF THE FOOT.]
Using a disk pierced with five holes, which gives twenty-five images per
second, the result shown in Fig. 12, which shows in full detail the
movements of the left half of the body, head, arm, and leg, was obtained
by this method for the action of running. Every fifth image is a little
stronger than the others. This is effected by making one of the
apertures in the disk larger than the others. The time of exposure is
thus increased, and the intensity of the image is greater. The object
of this disposition is to furnish base marks, by means of which it is
always easy to recognize traces corresponding to the same image, that is
to say, to a given attitude of the runner. For detailed studies a part
of the image is screened, as shown in Fig. 13. These diagrams are very
well adapted for the comparison of two sorts of movements whose
difference cannot be discerned by the eye. Thus, in jumping from an
elevation the shock caused by the feet striking the ground is reduced in
intensity by bending the legs, while the extensor muscles operate to
sustain the weight of the falling body. Our next two engravings show two
kinds of jumps: the first, the flexure of the legs and the reduction of
the shock; the second, with the leg almost straight, which implies a
severe shock by the feet striking the ground.
[Illustration: FIG. 15.--INELASTIC JUMP UPON THE HEELS.]
The practical applications of chronophotography are soon seen. Just as
machines are driven so as to obtain a useful effect at the smallest
expenditure of power, so a man can govern his movements so as to produce
the wished-for effects with the least waste of energy, and,
consequently, with the least possible fatigue. Of two gaits which can
carry us over a definite space in a given time, the one should be
preferred which costs the least possible fatigue. Chronophotography
furnishes the missing elements of the problem, giving exactly the
velocity of the different parts of the body, by the balancing of which
we can determine the masses in movement. From a long series of
comparisons, important conclusions can be drawn, as, for example, the
following: in walking, the most favorable gait is one where step
succeeds step at the rate of about one hundred and twenty a minute; for
running, the step should be nearly two hundred and forty a minute. Fewer
or more numerous steps will give less effect at a greater expenditure of
the work. The applications are therefore obvious; they enable us to fix
the rate of steps of soldiers to economize as much as possible their
strength in the severe trials to which they are subjected. These studies
have been followed out at great length, under varying conditions, using
a considerable number of subjects; and the results, while not final,
have shown that the true method has been found. Experiments have
confirmed that which the laws of mechanics could not foretell when the
dynamic conditions of the work of man were incompletely known.
[Illustration: FIG. 16.--OSCILLATION OF THE FORE LEG IN A GALLOP.
INTERVAL BETWEEN EXPOSURES ONE TWENTY-FIFTH OF A SECOND.]
M. Marey’s studies of the legs of the horse are particularly
interesting. We give one engraving showing the oscillation of the fore
leg of a horse in a gallop.
The analysis of the flight of birds presents special difficulty. Owing
to the extreme rapidity of the movements of the wings, an extremely
short exposure is required. The direction, often capricious, of the
flight of the bird, and the length of the path which must be followed,
to include on the sensitized plate sufficiently sharp images, add to the
difficulty. Several repetitions of the same experiment are generally
required before success.
The photographic gun is particularly valuable for taking photographs of
birds. Our engravings show the mechanism of the photographic gun and the
method of using it.
We present a photograph of a gull taken during its flight and an
enlargement of the same.
The photographic gun will be understood by reference to the engraving,
and is fully described in the “Scientific American Supplement,” No. 386,
to which the reader is referred.
We also give photographs of a pigeon rising in flight and the successive
attitudes of a gull.
Space forbids us to more than state that the analysis of the flight of
birds is a most interesting and important subject, and the results
obtained by chronophotography are most gratifying.
[Illustration: FIG. 17.--MODE OF USING THE PHOTOGRAPHIC GUN.]
[Illustration: FIG. 18.--MECHANISM OF THE PHOTOGRAPHIC GUN.
1.--General View of the Apparatus.
2.--The Shutter and Perforated Disk.
3.--Box containing Twenty-five Sensitized Plates.]
[Illustration: FIG. 19.--PHOTOGRAPH OF A GULL TAKEN DURING ITS FLIGHT.]
[Illustration: FIG. 20.--ENLARGEMENT OF AN IMAGE TAKEN BY THE
PHOTOGRAPHIC GUN.]
[Illustration: FIG. 21.--ENLARGEMENT OF ANOTHER IMAGE OF A BIRD TAKEN BY
THE SAME APPARATUS.]
The analysis of locomotion in water is one of the most interesting
developments of chronophotography. In order to study locomotion in water
it was necessary to modify the method. The animals experimented with
swam in a glass-sided aquarium fitted in an aperture in a wall, as shown
in our engraving. The aquarium was directly illuminated by the light of
the horizon, forming a very clear field upon which the animals were
outlined as silhouettes. Sometimes the external glass of the aquarium
was covered by letting down an opaque shutter; then, upon opening
another shutter, placed above the water, the brightly illuminated
animals were seen standing out from the black field. In most cases it
was found necessary to operate before the luminous ground, so it was not
possible to receive several successive images upon a removable plate,
but it was necessary to cause the sensitized surface to move by
starts, so as to bring before the objective points which were
always new for each new image that is to be formed. A flexible
gelatino-bromide-of-silver film was used. The film was cut into a long
and narrow strip which in the camera passed along at the focus of the
objective, and unwound from a supply bobbin, and wound around a
receiving one.
[Illustration: FIG. 23.--PIGEON RISING IN FLIGHT.
The successive images correspond to less and less advanced phases of the
wing’s revolution.]
[Illustration: FIG. 23.--ELEVEN SUCCESSIVE ATTITUDES OF A FLYING GULL.
In this series of images, traced from the originals, the distances
representing the positions of the bird in space are exaggerated to avoid
confusion.]
The objective turned toward the right has a slit in the center for the
passage of the diaphragm which, in revolving, allows the light to pass
intermittingly. When the small diaphragm makes one revolution the large
one makes five revolutions, and it is then only that the apertures meet
and the light passes. The bellows behind the objective allows the light
to reach the sensitized film. The box is, of course, tightly closed. The
focusing is done by means of a small telescope or spy glass. It is
necessary at each new experiment to use a new band of film, and the
substitution of rolls of films is effected in the light by means of
bobbins upon which the film is rolled.
At the extremity of each band of film are glued paper bands of the same
width. One of these prolongations is red and the other is black. Each of
them is about twenty inches in length. Having the two colors makes it
almost impossible to reëxpose a film, as one is not liable to confound a
bobbin which has been used with one that has not, the color of the roll
being different. Special devices are employed in the camera to render
the film immovable for an instant while it receives the impression from
the object. Arrangements are also provided for obtaining a uniform
velocity. The use of the apparatus which we have just described
permitted of seeing with what a variety of means of locomotion the
various kinds of aquatic animals--fishes, mollusks, crustaceans,
etc.--propel themselves. The motion of the medusa is particularly
interesting, and the phases of the movement of the umbrella are shown in
Fig. 26. The propulsion of this mollusk is effected through the
alternate contraction and dilation of its umbrella. Ten images per
second were sufficient to obtain a pretty complete series of the phases
of this motion. These images gain much by being examined in the
zoetrope, wherein they reproduce with absolute perfection the aspect of
the animal in motion.
[Illustration: FIG. 24.--ARRANGEMENT OF THE AQUARIUM FOR THE STUDY OF
AQUATIC LOCOMOTION.]
The hippocampus, which is otherwise known as the “sea-horse,” affords
another interesting example of aquatic locomotion. The principal
propeller of this animal is a dorsal fin which vibrates with such
rapidity that it is almost invisible, and has an appearance analogous to
that of the branches of a tuning fork in motion. With twenty images per
second it is seen that this vibration is undulatory. We have before us
the successive deviations of the lower, middle, and upper rays of the
film. In the present case the undulation takes place from the bottom
upwards.
[Illustration: FIG. 25.--PHOTOCHRONOGRAPHIC APPARATUS.]
The comatula is habitually fixed to the bottom of the aquarium, just as
a plant is fixed to the earth by its roots. It therefore makes nothing
but vague motions of the arm, which it rolls up and unrolls; but if the
animal be excited by the means of a rod, it will be observed to begin a
strange motion which carries it quite a distance. In this kind of
locomotion the ten arms move alternately; five of them rise and keep
tightly pressed against the calyx, and the other five descend and
separate from it. Upon the arms that rise, the cirri are invisible, and
while upon those that descend, they diverge in order to obtain a
purchase upon the water. These motions of the cirri seem passive, like
those of a valve that obeys the thrust of a liquid.
M. Marey says: “I have obtained images of a certain number of other
aquatic species, the swimming of the eel, the skate, etc. These types of
locomotion ought to be studied methodically, compared with each other,
and considered in their relations with the conformation of the different
species. It will, I hope, be a new element for the interpretation of the
laws of animal morphology, which are very obscure.”
[Illustration: FIG. 26.--MOTIONS OF THE UMBRELLA OF THE MEDUSA.]
M. Marey has also investigated the flight of insects by means of
chronophotography. These experiments are most delicate and interesting,
and the results obtained go a long way towards making up a satisfactory
theory of insect life. M. Marey says that the wing in its to-and-fro
movements is bent in various directions by the resistance of the air.
Its action is always that of an inclined plane striking against the
fluid, and utilizing that part of the resistance which is favorable to
its onward progression. This mechanism is the same as that of a
waterman’s scull (reference of course being to “sea sculling”, and not
to “river sculling”), which, as it moves backward and forward, is
obliquely inclined in opposite directions, each time communicating an
impulse to the boat. There is, however, a difference between these two
methods of propulsion. The scull used by the waterman offers a rigid
resistance to the water, and the operator has to impart alternate rotary
movements to the scull by his hand--at the same time taking care that
the scull strikes the water at a favorable slant. The mechanism in the
case of the insect’s wing is far simpler. The flexible membrane which
constitutes the anterior part of the wing presents a rigid border which
enables the wing to incline itself at the most favorable angle. The
muscles only maintain a to-and-fro movement. The resistance to the air
does the rest, namely, effects those changes in surface obliquity which
determine the formation of an 8-shaped trajectory by the extremity of
the wing.
M. Marey states that he succeeded in obtaining a photograph of the
gilded wing of an insect, which, though not absolutely at liberty, could
fly at a comparatively high rate of speed. The photographs of the
trajectory of the wing of an insect are very interesting. A wooden box
was lined throughout with black velvet. The bottom of the box, a simple
disk supported by a foot piece, was placed in position; the periphery of
the space was covered with a white material, leaving between it and the
central disk an annular track covered with black velvet. It was around
this annular track the insect was made to fly. A needle stuck in the
middle of the disk served as an axis for a revolving beam and its
counterbalance. This beam consisted of a straw, and at the end of it was
fixed a light pair of forceps to hold the insect. The dragon fly
commenced flying around the track at a very rapid rate, drawing the
straw after it. The gold spangles passing through his wings described a
trajectory which was easily photographed.
[Illustration: FIG. 27.--MOTIONS OF THE DORSAL FIN OF THE SEA-HORSE.]
The chronophotography of insects by the use of a moving film has been
also accomplished by means of very ingenious apparatus. In some cases
the insects were held in forceps, and in other cases they were allowed
free flight in a cardboard box.
“Comparative locomotion,” which is rendered possible by
chronophotography, might almost be called a new science. It is, at any
rate, an important adjunct to the studies of the zoölogist. The
researches of M. Marey upon the different terrestrial mammals, birds,
tortoises, lizards, frogs, toads, tadpoles, snails, eels, fish, insects,
and arachnids are of the greatest possible value and interest. The
applications of chronophotography to experimental physiology are
numerous. It supplements the information obtained by the graphic
methods. It has rendered possible the photography of the successive
phases of cardiac action in a tortoise under condition of artificial
circulation. The mechanism of cardiac pulsation has also been studied by
its means, as well as the determination of the centers of movements in
joints.
It has been found that chronophotography could be applied not only to
objects of considerable size, but to those of microscopic size as well.
Special arrangements of apparatus are necessary for this purpose. By its
means the retraction of the spiral stalks in vorticellæ, the movement of
the blood in capillary vessels, and the movements of the zoöspores in
the cells of conferva have been determined.
[Illustration: FIG. 28.--MOTIONS OF THE COMATULA.]
[Illustration: FIG. 29.
TORPEDO BADLY FIRED.
TORPEDO PROPERLY FIRED.]
The great value of chronophotography is unquestionable for use in every
case where the body whose rapid changes of position or form we wish to
know is inaccessible to us, or its movements cannot be mechanically
traced.
Chronophotography has been used in France for studies touching the
military art, being employed for registering the firing of projectiles
having a relatively slow motion, such as the explosion of stationary
torpedoes, the recoil of guns, the motion of automobile torpedoes, etc.
Special arrangements are provided to permit of electrically controlling
the phenomenon to be photographed. The apparatus is described in detail
in the “Scientific American Supplement,” No. 743.
We present a diagram showing the results obtained by photographing the
firing of torpedoes. Although the velocity of these projectiles is not
very great, about sixty feet per second, it is yet very difficult for
the eye to take exact account of what is occurring during the launching.
As the net cost of a torpedo is considerable, it is essential that the
conditions which influence the regularity of its submarine flight shall
be known with precision. If it inclines in front more or less in
plunging, the regularity of its running will be put to hazard; if, on
the contrary, it falls flat upon the water, the results will be very
different. Our engraving shows the torpedo starting from the tube and
traversing the different panels in the field of firing. In the first
half the torpedo, gradually inclining, falls point foremost; it has been
badly fired. In the second series, on the contrary, the torpedo is
maintaining itself horizontally, and, in a manner, moving always
parallel with itself. Under such circumstances it falls flat and starts
off normally and regularly to the object to be reached. This shows the
great utility of chronophotography.
AN AMATEUR CHRONOPHOTOGRAPHIC APPARATUS.
[Illustration: FIG. 1.--AMATEUR’S CHRONOPHOTOGRAPHIC APPARATUS.]
The experiments which we have been describing necessitate apparatus of
the most expensive kind, and they are unadapted for the use of the
amateur. The apparatus of M. Georges Demeny, which we illustrate, is,
however, very simple. The reader needs to be reminded that there are
three types of chronophotographic machinery in use, in two of which a
single objective, with a disk shutter revolving at great speed, is
employed. In one the object shifts, and gives several images from an
immovable plate, while in the other the object is stationary, and the
movable sensitized surface gives well-separated images. The third
method, which is the least interesting, consists in taking as many
objectives and plates as it is desired to have images, and in freeing
the shutters of each objective, one after the other. The most scientific
solution of the problem is that which permits of obtaining upon a band
of film, and with a single objective, a succession of well-separated
images whose number depends only upon the length of the band employed.
The difficulty in using a sensitized band consists in arresting it for
the very brief instant in which each image impresses the plate. The
Demeny apparatus which we are about to describe is very simple. A wooden
box having about the dimensions of an ordinary seven by nine inch
apparatus is provided with an objective of wide aperture, of which only
the center is utilized. Back of this objective, and as near as possible
to the sensitized surface, the disk shutter is revolved by means of a
crank. Up to this point there is really nothing new in the apparatus;
but the principal improvement consists in the unwinding and arrest of
the sensitized film. Number 1 of our first engraving represents the
principle of the system. Two disks, R and P, are each mounted upon an
axis passing through their centers; bobbins that carry the films are
fixed, one of them at R, upon a spindle mounted in the axis of rotation
of the disk, and the other at P, upon a spindle mounted eccentrically to
such axis. It is this eccentric position that chiefly constitutes the
invention. Let us suppose that the two bobbins are in place, as shown in
cut. The film wound upon A, having one of its extremities attached at B,
follows the course, C, S, during which it passes behind the objective;
the two bobbins cannot have any proper motion in consequence of the
method of fixing which is adopted; they and the disks, R and P, that
support them, become interdependent. Because the disk, P, revolves, the
film coming from A will wind around B; but, in consequence of the
eccentric position of this bobbin upon the disk, traction will cease to
occur for a very brief instant at the moment at which the bobbin, B,
approaches A as closely as possible, Despite this, as the winding
always proceeds to a degree proportional to the unwinding, the film
remains perfectly taut. It is at this moment that the window, H, of the
disk, L, uncovers the objective for an instant. It will be understood
that the crank, M, sets the disk in motion, and it is this, through a
mechanism of gears, that controls the operation of the bobbins. There
is, therefore, an exact mathematical coincidence between the arrest of
the film and the passage of the window, and this is essential for the
sharpness of the image. This would not always occur if a friction device
was depended upon for the rest of the film, for in this case a sliding
might occur which would produce a blurring of the image. The solution
offered by the Demeny apparatus is, therefore, the simplest and one of
the surest known. The simplification of the mechanism has permitted of
constructing an apparatus light enough to allow of operating without a
tripod, by holding it in the arms, as shown in our second engraving.
Each film terminates in a strip of black paper glued to it, and forms a
complete covering after the winding upon the bobbin. This arrangement
protects the sensitized part from the light, and permits of changing the
bobbin in daylight. Twenty of them can be stored in the spaces in the
box left by the mechanism, so that one may always have a large supply on
hand.
[Illustration: FIG. 2--METHOD OF USING THE DEMENY APPARATUS.]
CHAPTER III.
THE PROJECTION OF MOVING PICTURES.
THE EDISON KINETOGRAPH.
[Illustration: PHOTO-ENGRAVING OF A PORTION OF THE STRIP NEGATIVE OF THE
KINETOGRAPH (ACTUAL SIZE).]
The “kinetograph,” which is the precursor of the apparatus for showing
moving photographs, is of great interest. The kinetograph as first
proposed consisted of a clever combination of a photographic camera and
the phonograph, by which the words of a speech or play were to be
recorded simultaneously with photographic impressions of all the
movements of the speakers or actors. The photographic impression is
taken at the rate of forty-six per second. The celluloid film upon which
the photographic impressions are taken is perforated along one edge with
a series of holes, arranged at regular intervals with as much precision
as can be secured by means of the finest perforating mechanism, to
secure perfect registry. This was found necessary because the
phonographic cylinder must be in exact synchronism with the
shutter-operating and film-moving devices of the camera. The phonograph
and camera mechanisms are driven by the same motor and controlled by the
same regulating mechanism. The greatest difficulty was experienced in
devising mechanism for the stopping and starting of the film. It was
found that the stopping and starting of the film forty-six times a
second required about two-thirds of the time, the remainder being
utilized for the exposure of the plate. To take these pictures special
camera lenses of large aperture had to be constructed. The reproducing
apparatus is practically a reversal of the camera; that is, a superior
form of projecting lantern is employed which is provided with a strong
light, and mechanism for moving forward the strip with an intermittent
motion, corresponding exactly to the motion of the negative strip in the
camera. The lantern is furnished with a light interrupter which eclipses
the light during the brief period required for shifting the film
forward to a new position to show the succeeding picture. The apparatus
was largely manufactured on a small scale, without the phonograph, for
use in railway stations, cigar stores, etc. It was found to be almost
impossible to combine the two instruments. In this case the pictures
were not projected upon the screen, but were upon a ground-glass plate
which the observer looks at.
REYNAUD’S OPTICAL THEATER.
Up to the time of the invention of this theater, the apparatus that
produced the synthesis of the successive phases of an action were
limited to reproduction upon a very small scale, which can only be
enjoyed by a limited group. The object of the optical theater was to
provide an apparatus for the reproduction of a series of actions upon a
considerable scale. The continuity of the image obtained by the
praxinoscope, invented in 1877 by M. Reynaud, had not up to this time
been realized by any projecting apparatus. The effect is produced by
using a crystalloid band upon which the images are painted as
represented at A in our engraving. The operator can revolve it in one
direction or the other by means of two reels. The images pass before the
lantern, B, and are projected by the aid of the objective, C, upon an
inclined mirror, M, which projects them upon the transparent screen, E.
Another projection lantern, B, causes the appearance on the screen of
the scene, amid which appear the characters, which change their posture
according as the painted band, A, is revolved by the operator.
[Illustration: REYNAUD’S OPTICAL THEATER.]
ELECTRIC TACHYSCOPE.
The apparatus which we are about to describe is an important link in the
history of the synthesis of animated motion. The apparatus is the
invention of Ottamar Anschuetz, of Lissa, Prussia. A special camera was
used, adapted to take a number of photographs in quick succession. The
instrument for displaying the pictures is called the “electrical
tachyscope.” It consists of an iron wheel of sufficient diameter to hold
an entire series of positive prints on the periphery. The wheel is
arranged upon a rigid standard, and provided with a series of pins which
register exactly with the picture. Upon the standard behind the wheel is
located a box containing a spiral Geissler tube which is connected with
the terminals of a Ruhmkorff coil. The primary coil is provided with a
contact maker and breaker adapted to be operated by the pins projecting
from the wheel, so that every time a picture comes before the Geissler
tube it is illuminated by an electrical discharge through the tube.
This discharge, being instantaneous, shows each picture in an apparently
fixed position. These pictures succeed each other so rapidly that the
retinal image of one picture is retained until the next is superimposed
upon it, thereby giving to the observer the sense of a continuous image
in constant motion.
[Illustration: ANSCHUETZ’S ELECTRICAL TACHYSCOPE.]
THE DEMENY CHRONOPHOTOGRAPHIC APPARATUS.
The chronophotographic apparatus which we illustrate was invented by M.
G. Demeny, who is the assistant of Dr. Marey, whose work in
chronophotography we have already described. As long ago as 1891, M.
Demeny was able to project upon a screen figures which simulated the
motion of animal life.