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                    THE MENTOR 1918.08.01, No. 160,
                              Photography




                            LEARN ONE THING
                               EVERY DAY

                   AUGUST 1 1918      SERIAL NO. 160

                                  THE
                                MENTOR

                              PHOTOGRAPHY

                                  By
                           PAUL L. ANDERSON

                   DEPARTMENT OF           VOLUME 6
                   FINE ARTS              NUMBER 12

                          TWENTY CENTS A COPY




A Voice From Far Cathay


_Dear Mentor_:--One of my most respected college professors advised his
classes to review their several groups of studies every seven years,
and in the broad, I agree with the advice. It is just this review that
The Mentor gives some of us. The Mentor is not _learned_. It furnishes
a most readable review, with pithy editorials and discriminatively
selected pictures. It can be appreciated by the man who has never been
outside the town of his birth, and it can be enjoyed by the person who
has converted stamped gold into the legal tender which lets one into
the city, or gallery, or park, or museum, or observatory described; and
it can be read with profit by the one who is interpreting life in the
class room.

I usually read it by bits between courses at the dinner table, and it
often has taken the place of another seat. It has this advantage: it
never talks shop, save in an entertaining way.

The pictures make good material for “identification” or “information
tests.” A selection of twenty makes good material for one “stunt” of an
evening for a small group of guests.

But I like them best for use in a bulletin board in my class room.
With titles or brief notes translated into Chinese, they attract the
students around the board between classes. It is an easy matter to have
a series of fifteen or twenty groups through the year, that are of
interest to one’s students, and give real information and stimulus.

This letter is not designed to lead you to believe that the publication
takes its place with the essential possessions of the American
missionary in the Orient--the Bible, Montgomery Ward catalog, and
tennis racquet--but it is written that you may know that it helps one
to keep “fit.”

In appreciation, yours,

DANIEL S. DYE

West China Union University

Chengtu, West China

       *       *       *       *       *

THE MENTOR ASSOCIATION

ESTABLISHED FOR THE DEVELOPMENT OF A POPULAR INTEREST IN ART,
LITERATURE, SCIENCE, HISTORY, NATURE, AND TRAVEL

THE MENTOR IS PUBLISHED TWICE A MONTH

BY THE MENTOR ASSOCIATION, INC., AT 114-116 EAST 16TH STREET, NEW
YORK, N. Y. SUBSCRIPTION, FOUR DOLLARS A YEAR. FOREIGN POSTAGE 75
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CENTS. PRESIDENT, THOMAS H. BECK; VICE-PRESIDENT, WALTER P. TEN EYCK;
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AND ASSISTANT SECRETARY, H. A. CROWE.

    AUGUST 1st, 1918.      VOLUME 6.      NUMBER 12.

Entered as second-class matter, March 10, 1918, at the postoffice at
New York. N.Y., under the act of March 3, 1879. Copyright, 1918, by The
Mentor Association, Inc.




[Illustration: BY PAUL L. ANDERSON

PHOTOGRAPH FROM A DAGUERREOTYPE]




_PHOTOGRAPHY_

_A Daguerreotype_

ONE


Louis Jacques Mande Daguerre (born 1789, died 1851), was a great French
scene-painter who experimented for many years trying to find some way
of rendering permanent the image projected by a lens. J. Nicéphore
Niépce was engaged in the same research, and from 1829 until the death
of Niépce in 1833 the two worked together, but it was not until some
years after the latter date that Daguerre discovered the process that
bears his name. This process may be briefly described as follows: a
highly polished and perfectly clean silver plate is rendered sensitive
to light by the formation of a deposit of silver iodide on the
surface, this being accomplished by exposing the plate--of course in
the dark--for some minutes to the vapor of iodine. When the plate has
assumed a uniform golden-brown color it is placed in the camera and the
exposure is made, the light projected by the lens causing a chemical
change to take place in the silver iodide. The image thus obtained
is very weak, and in order to strengthen it the plate is exposed for
some minutes to the vapor of mercury. It is subsequently fixed, or
rendered permanent, by bathing with a solution of sodium thiosulphate
(ordinarily known to photographers as “hypo”). This dissolves the
silver compounds that were not affected by light. In some cases the
picture is still further strengthened by treating it with chloride of
gold. This not only increases the vigor of the image but at the same
time improves its stability, so that it is less likely to fade as the
result of atmospheric action or exposure to light. The effect of the
chloride of gold is literally to gold-plate the image. As the surface
of the completed daguerreotype is very sensitive to any mechanical
action, it must be protected by glass. A mere touch of the finger
leaves an irremediable scratch.

The daguerreotype was at one time very popular for portraiture, but
the process has certain drawbacks that have caused it to be superseded
by improved methods. Among these drawbacks are the following:
The exposures required are rather long; it is impossible to make
duplicates--a separate exposure must be made for each picture; the
picture must be held at a certain angle to make it visible, and the
process is rather expensive and laborious to work. Nevertheless,
exquisite effects may be obtained in daguerreotype; the writer has
seen pictures of this kind which for sheer beauty yield to none of the
modern printing mediums.

The decadence of the daguerreotype is to be regretted for at least one
reason,--the man who elected to work in that medium was necessarily at
least a craftsman, whereas at the present time many photographers are
neither artists nor craftsmen, but merely mechanics of only fair skill.
Photography has been brought to such a state of perfection that good
technical results may be obtained by persons that work by rote and know
absolutely nothing of the principles underlying the craft. This lack of
training and enthusiasm for the work must evidently be reflected in the
results obtained.

There are few forms of portraiture art that equal in beauty choice
early examples of daguerreotype photography. They have the exquisite
delicacy, softness and individual charm of the best miniature
portraits. Good old daguerreotypes are treasured possessions in the
homes of many families--and rightly so, for they combine a fine quality
of art with a gentle personal appeal.

    WRITTEN FOR THE MENTOR BY PAUL L. ANDERSON
    ILLUSTRATION FOR THE MENTOR. VOL. 6, No. 12, SERIAL No. 160
    COPYRIGHT, 1918, BY THE MENTOR ASSOCIATION, INC.




[Illustration: FROM A PRINT BY ALVIN LANGDON COBURN

SELF-PORTRAIT PHOTOGRAPH--BY D. O. HILL]




_PHOTOGRAPHY_

_Portraits by D. O. Hill_

TWO


David Octavius Hill (born 1802, died 1870), was a Scotch painter who
conceived the idea of producing a great historical picture representing
the Disruption of the Church of Scotland. This work involved painting
some four or five hundred portraits, and Hill, despairing of obtaining
satisfactory sittings from so many persons, turned to the newly
discovered art of photography to furnish the portraits he needed, with
the idea of using the photographs as a guide in painting. Hill used
the calotype process, invented by Fox Talbot, which rendered a piece
of paper sensitive to light by coating it with iodide of silver. When
it was exposed in the camera and developed, a negative resulted, and
positive prints were made from this negative in the same medium.

Hill became so much interested in photography that he worked with
it for several years, to the neglect of his painting. During those
years he produced photographic portraits which have certainly never
been surpassed, and which some people think have never been equalled.
The exposures necessary were very long--four or five minutes in
bright sunlight. This fact lends a great deal of beauty to the
results, for there is no doubt that full sunlight gives effects that
cannot be obtained in any other way, and these may be of surpassing
beauty, provided the photographer is skilful enough to manage his
apparatus and pose the sitter properly. It is regrettable that so many
photographers of the present day shun out-door portraiture, for there
is unquestionably a great opportunity in that class of work. The claim
of some photographers that out-door light is not satisfactory for
portraiture is refuted by Hill’s results.

Hill was not a great painter. His works in that medium are well-nigh
forgotten, but he was unquestionably a man of great sensitiveness, who
possessed the quality of psychic insight so necessary to a portrait
worker. It is the estimate of an authority that, though he could never
be compared with the great masters of portraiture, Rembrandt and
Velasquez, nevertheless his works are entitled to a place in the second
rank.

Hill was especially fortunate in his sitters, for the men and women
that he photographed were persons whom it would be difficult to
render commonplace in appearance, among them being Christopher North
(Professor John Wilson), J. G. Lockhart, Lady Ruthven, Robert Haldane,
William Henning, Mrs. Anna Brownell Jameson, and others of equal note
in Great Britain.

The paper negatives made by Hill are carefully preserved. The writer
is fortunate in the possession of prints from two of these negatives.
The reproduction shown herewith, a gum-platinum plate made and given to
him by Alvin Langdon Coburn, is from one of them. Much of the beauty of
this example of Hill’s work is due to modern printing methods, but the
quality in this negative, brought out in the print, proves undeniably
that Hill merits recognition as a master of portraiture.

    WRITTEN FOR THE MENTOR BY PAUL L. ANDERSON
    ILLUSTRATION FOR THE MENTOR. VOL. 6, No. 12, SERIAL No. 160
    COPYRIGHT, 1918, BY THE MENTOR ASSOCIATION, INC.




[Illustration: PHOTOGRAPHED AT YERKES OBSERVATORY, WILLIAMS BAY,
WISCONSIN. OCTOBER 19, 1911

BROOKS’ COMET--ASTRONOMICAL PHOTOGRAPH]




_PHOTOGRAPHY_

_Astronomical Photography_

THREE


Photography has made possible many discoveries of tremendous importance
in the realm of astronomy by revealing the existence of stars too
faint--because of their small size or great distance--to be seen by the
eye. This is one of the most conspicuous ways in which the sensitive
plate has been an aid to the scientist. A device for carrying a
photographic plate is attached to a telescope and the plate exposed
to the image projected by the telescope for a prolonged period. This
may, in fact, amount to several hours; exposures are sometimes partly
completed one night and finished the next, a comparatively small
area of the heavens being chosen for investigation at one time. On
development of the plate the stars are counted and compared with
existing charts of the area in question. Of course this method requires
that the telescope move with the same angular velocity as that of
the earth’s rotation, so that the image of each star may remain in
precisely the same position on the plate during the entire time of
exposure. Otherwise the star would be represented as a trail of light,
the slightest variation in the speed of rotation being sufficient to
cause blurring of the image. It is apparent that the clockwork employed
for driving the telescope must be a marvel of accuracy.

The power which this method possesses of revealing hitherto
undiscovered stars depends on a curious fact. If an observer looks
into the eye-piece of a telescope he can discern only those heavenly
bodies that send to the earth a certain minimum of light; but when a
photographic plate is exposed for long periods there is a cumulative
effect of light on the sensitive emulsion. That is, the long-continued
impact of the light rays causes, little by little, a gradual change
in the constitution of the sensitive silver salt. The action thus
piles up, so to speak, and records light that is far below the visible
minimum.

The photographic plate has not only aided discoveries in the vast
realms of interstellar space, but has also revealed to us things so
exceedingly minute that no other method of observation could bring them
within the range of our perceptions.

    WRITTEN FOR THE MENTOR BY PAUL L. ANDERSON
    ILLUSTRATION FOR THE MENTOR. VOL. 6, No. 12, SERIAL No. 160
    COPYRIGHT, 1918, BY THE MENTOR ASSOCIATION, INC.




[Illustration: BY PAUL L. ANDERSON

PORTRAIT--BY THE BROMOIL PROCESS]




_PHOTOGRAPHY_

_A Bromoil Print_

FOUR


In the bromoil process, the first step is to make a bromide
enlargement. The negative from which a print is to be made is placed in
an apparatus resembling the familiar stereopticon and an enlarged image
is projected on a piece of bromide paper, or paper that has been coated
with an emulsion similar to that used for plates. After the paper has
been exposed to the image it is developed, fixed and washed, the result
being a large positive print of the original small negative. Often this
print is allowed to remain as it is, and it is then known as a bromide
enlargement, or, simply, an enlargement; sometimes the worker converts
it into a bromoil.

The image in an enlargement consists of metallic silver in a film of
gelatine, the gradations of the picture resulting from the varying
thicknesses of the silver image. The first step toward changing this
to a bromoil is to treat it with certain chemicals that bleach out the
silver image and at the same time harden the gelatine in proportion
to the amount of silver present. The bleached print is then soaked in
warm water, and the high-lights of the picture, where the gelatine is
least hardened, absorb the water freely, the half-tones less so, and
the shadows least of all. An oily ink, then dabbed on the print with a
brush, adheres freely in the shadows, less freely in the half-tones,
and least of all in the lights, being repelled by the water in the
film. The final result is a print in which the image is formed by
varying thickness of ink, which, of course, may be of any color.

The advantages of bromoil over bromide are numerous. In the first
place, a bromide print cannot be regarded as absolutely permanent, but
a bromoil may be. Next, the color of a bromide print is limited to
black and varying shades of brown, unless chemical toning is resorted
to, which still further reduces the stability of the image. But a
bromoil may be of almost any color, and, indeed, of different colors
in different portions of the picture. The greatest advantage of the
bromoil process, however, lies in the fact that as much or as little
ink as may be desired can be put on any given area. By varying the
consistency of the ink it can be made to adhere more or less freely.
By modifying the brush action it can be placed on the print or omitted
from it, and can even, at times, be removed after being deposited
on the paper. It will be seen that the artist has complete control
over the gradations, and to some extent, also, over the outlines of
the picture. He can therefore make the process respond to his desire
for artistic expression to an extent not possible with any other
photographic printing medium, even the superficial texture of the image
being largely under the worker’s control.

A variant of bromoil is the oil process, though it would be more
correct to put it the other way about, the latter process being the
older of the two. A sheet of paper is coated with gelatine alone, this
being rendered sensitive to light by means of certain chemicals and
then printed under a negative. The effect is to render the gelatine
hard in proportion to the amount of light-action, that is, hardest
in the shadows, less so in the half-tones, and least of all in the
lights. The print is then washed to remove the excess of sensitizer,
and soaked in warm water; the subsequent operations are the same as
in bromoil. Oil is superior to bromoil in being slightly easier to
manipulate and in not requiring a dark-room, but it is inferior in that
it demands either daylight or a powerful artificial light for printing.
Furthermore, a negative the size of the finished print is necessary,
whereas with bromoil, large prints can be made from small negatives.

Oil and bromoil have the drawback of not being very rapid to work,
three or four 11×14 bromoils representing a good day’s work for a
careful manipulator, but they are by far the most satisfactory of
all photographic printing mediums when the desire is for artistic
expression.

    WRITTEN FOR THE MENTOR BY PAUL L. ANDERSON
    ILLUSTRATION FOR THE MENTOR. VOL. 6, No. 12, SERIAL No. 160
    COPYRIGHT, 1918, BY THE MENTOR ASSOCIATION, INC.




[Illustration: PHOTOGRAPH BY PAUL L. ANDERSON

THE LAKE, WINTER--NATURE PHOTOGRAPHY]




_PHOTOGRAPHY_

_Pictorial Photography_

FIVE


The accompanying photograph entitled “The Lake, Winter,” illustrates
admirably the use of the soft-focus lens. It is also of interest as
showing the advantages sometimes to be gained from the intentional
use of defects. The normal human eye is unsurpassed for the purpose
for which it is designed; it is difficult to imagine an organ
more perfect in this respect. The eye automatically, and almost
instantaneously, adjusts itself for near or distant objects and for
varying intensities of light, and has, moreover, a field of view of
nearly 180 degrees--almost a complete half-circle. Nevertheless, it
has two defects that tend to impair the accuracy of vision, namely,
chromatic and spherical aberration. Chromatic aberration is the
inability to focus simultaneously on two or more of the primary
colors (it is this defect in the eye that causes red letters to seem
to stand out from a blue or green background, a trick sometimes used
in poster work). Spherical aberration is the inability to bring to a
focus the rays of light that pass through the lens near the margins at
the same time as those that pass through near the center. For these
reasons--and, in lesser degree, some others--the eye cannot see sharp
lines, and a lens that gives sharp definition to the edges of objects
produces results that are esthetically unpleasing, because foreign
to our experience. The soft-focus lens--of which there are numerous
makes--is so designed that it possesses the errors that are normal to
the eye, and therefore--if the characteristic softness of definition
is not over-done by a too enthusiastic worker--gives results having an
agreeable vagueness of outline. At one time the qualities of this type
of lens were over-worked, the results being so excessively diffused
that, as one writer said of a print, “it was impossible to tell whether
it was a ‘Portrait of a Lady’ or a ‘Water-Spout in the Gulf Stream.’”
But for some years past the pendulum has been swinging the other way,
and photographers in general (it must be understood that this refers
only to artistic workers, not scientists) are now using the unconnected
lens so as to secure as nearly as possible the quality characteristic
of the normal eye with, perhaps, a slight exaggeration for the sake of
suggestion, and as a stimulus to the imagination.

    WRITTEN FOR THE MENTOR BY PAUL L. ANDERSON
    ILLUSTRATION FOR THE MENTOR. VOL. 6, No. 12, SERIAL No. 160
    COPYRIGHT, 1918, BY THE MENTOR ASSOCIATION, INC.




[Illustration: PHOTOGRAPH BY KARL STRUSS, BY COURTESY OF HARPER’S
BAZAAR.

PHOTOGRAPH ILLUSTRATION FOR A STORY]




_PHOTOGRAPHY_

_Motion Picture Photography_

SIX


A phase of photography that has a very broad scope is motion-picture
work, the mechanics of which depend on this fact: If an object is
looked at for a time and is suddenly removed from before the eye, the
eye continues to see it for an appreciable time after its removal. This
phenomenon is called “persistence of vision.” A motion-picture camera
is so arranged that a long strip of film can be drawn past the lens
in a series of jerks, the shutter being opened to permit the image
projected by the lens to fall on the film during the period that the
latter is at rest; the film is drawn on to the next position while the
shutter is closed. Naturally, an object moving before the lens will
move slightly during the interval between exposures, so the film, when
developed, shows a consecutive series of photographs of the object
in slightly different positions. A positive print is made from this
series of negatives on a similar strip of film. This is projected by
means of an apparatus something like the familiar magic lantern or
stereopticon, but so arranged that this film may be drawn along in
jerks. Each photograph is shown for a fraction of a second, and is
replaced, during the time that the shutter is closed, by one showing
a slightly later phase of the motion. Because of the persistence of
vision the eye blends these successive photographs into one apparently
continuous motion. It will be seen that the term “moving pictures” is
really a misnomer, since the pictures on the screen do not move, but
remain perfectly stationary during the time that they are seen. By
taking the pictures rapidly and projecting them slowly the apparent
motion may be slowed down, so that a rifle bullet may take three or
four minutes to travel across a screen space of as many feet. By taking
them at wide intervals and projecting rapidly the motion may be speeded
up, and a plant may seem to grow from a seedling to maturity in a few
minutes. The ordinary taking and projecting speed is sixteen pictures
per second, experiment having shown that this is the least number that
the eye will blend satisfactorily. Since each picture is one inch wide
by three-quarters of an inch high--in the film--it is evident that
each second of time represents one foot of film. The writer has seen a
rather elaborately staged photo-play that required an hour and forty
minutes for projection; a simple calculation shows that this involved
6,000 feet of positive film--a little over a mile. The length of the
negative film was undoubtedly more, on account of retakes, cuts, and so
on. An expenditure of five or six hundred dollars for film, however,
is but a small item in the cost of producing an elaborate photo-play,
for the actors receive large salaries--though not so large as the
press-agents would have us believe--and the cost of scenery is great.
The production of photo-plays is nevertheless a profitable industry, as
may be understood from the fact that the average daily attendance in
this country is estimated at about twelve million. Assuming that each
spectator pays only ten cents, this represents an intake of $1,200,000
daily and, as is well known, the prices of admission in many theatres
range from 25 cents up to $1.00 and more. The artistic possibilities
of the motion-picture play are obviously limited--it can never hope
to rise to the emotional heights of the legitimate drama--but they
are none the less considerable. It is to be regretted that the motion
picture industry is at present so much in the hands of producers who
pander to the coarser instincts of the public, through sensationalism
and slap-stick farce; who are often indifferent to detail--the
writer has seen a cow-puncher represented as wearing his six-shooter
butt-foremost; who treat the author’s work according to their own
ideas. A well-known author remarked, on seeing the screen version of
one of her books: “If I hadn’t been fairly familiar with the story I
wouldn’t have known what it was all about.” In general, firms seem to
be more concerned with getting the public’s money than with producing
really artistic results. The writer once saw a photo-play version of a
fairly well-known book, in which the producer had changed an elderly,
gray-haired, quiet, experienced cattleman into a cheap imitation of
a Bret Harte gambler of thirty years of age, the purpose of this
metamorphosis being to transform a noble and self-sacrificing affection
into a piece of gaudy sensationalism. Such tactics cannot fail to
displease thinking people, but there are, fortunately, producers to
whom these remarks do not apply--really conscientious men of high
ideals, and signs are not wanting of an improvement in this regard. The
motion picture, in worthy hands, can be made an educational medium of
great value, not only in the dramatic art but in many other ways. Films
frequently show scenes of historical interest, life in foreign lands,
industries. Scientific subjects are treated, such as the peristaltic
movements of the intestines and the action of the heart, photographed
by means of the X-ray; also the life cycle of micro-organisms, the
microscope being used in this case--and many other activities of life.
Among the most interesting of these films are those produced by the
Williamson brothers, showing sea life, though mechanical difficulties
have so far prevented the photographing of the most interesting phase
of marine life, that of the extreme depths.

    WRITTEN FOR THE MENTOR BY PAUL L. ANDERSON
    ILLUSTRATION FOR THE MENTOR. VOL. 6, No. 12, SERIAL No. 160
    COPYRIGHT, 1918, BY THE MENTOR ASSOCIATION, INC.




THE MENTOR ·· AUGUST 1, 1918 DEPARTMENT OF FINE ARTS

THE STORY OF PHOTOGRAPHY

By PAUL L. ANDERSON

_Artist Photographer, Author of “Pictorial Photography”_

    _MENTOR GRAVURES_

    PHOTOGRAPH FROM A DAGUERREOTYPE

    SELF-PORTRAIT PHOTOGRAPH _BY D. O. HILL_

    BROOKS’ COMET

    _MENTOR GRAVURES_

    PORTRAIT BY BROMOIL PROCESS

    THE LAKE, WINTER

    ILLUSTRATION FOR A STORY

[Illustration: A DAGUERREOTYPE]

Entered as second-class matter March 10, 1913, at the postoffice at New
York, N. Y., under the act of March 3, 1879. Copyright, 1918, by The
Mentor Association, Inc.


Numerous investigators, Daguerre, Niépce, Fox Talbot, and others,
have been credited with the discovery of photography, but the fact
seems to be that these, and many more, merely contributed, each in his
turn, some portion of the total that goes to make up the art as it
now stands. Photography means, literally, “light-writing,” the name
being derived from two Greek words, _phos_, light, and _graphein_, to
write. The practice of photography depends primarily on the fact that
certain chemical compounds are changed into other compounds by the
action of light. Another fact is closely allied with this, namely, that
a suitably constructed lens of glass or other transparent material,
or a fine needle-hole used instead of a lens, will project the image
of objects placed in front of it. A camera, then, consists of a
light-tight box having at one end an arrangement for holding a lens
or a card with a needle-hole in it, and at the other end a device for
holding some light-sensitive chemical to receive the image projected by
the lens. In modern practice this light-sensitive chemical is almost
always bromide of silver or a mixture of the bromide with other silver
compounds, these chemicals being held in an emulsion of gelatine. When
the gelatine emulsion is coated in a thin film on a sheet of glass
the result is known as a dry-plate, or, simply, a plate. When it is
coated on a strip of celluloid wound on rollers so that successive
portions may be exposed to light, it is called a roll film, and when
it is coated on separate sheets of celluloid, arranged like a pad, to
be exposed successively, it is called a film pack. A similar emulsion
coated on paper gives bromide or gas-light paper, which, as will be
seen later, is used for making prints. At one time wet collodion plates
were generally used, a sheet of glass being coated with collodion and
sensitized by bathing it with iodide of silver. The exposure was made
before the plate dried; but these plates were inconvenient to handle
and have been almost entirely superseded by the gelatine dry plate. The
prepared plate, of whatever type it may be, is placed in the camera
and exposed for a longer or shorter time, depending on circumstances,
to the light projected by the lens, but no image is visible after
exposure, (unless, indeed, the exposure has been tremendously
excessive,) and the plate must be developed.

[Illustration: From a platinum print by Gertrude Käsebier

“BLESSED ART THOU AMONG WOMEN”

Portrait Photograph]

[Illustration: From a photograph by Paul L. Anderson

A COUNTRY STATION MASTER

Portrait Photograph]

There are about fifty different reducing agents on the market;
most of them are derived from coal-tar, though some are made from
nut-galls, lichens, and other substances. The developer consists of a
solution in water of one or more of these reducing agents, with other
chemicals to control the action, the exposed plate being bathed in
this solution, either in the dark or in a light to which the plate
is not sensitive. Wherever light has acted on the silver salts the
developer causes metallic silver to be deposited in proportion to
the amount of light-action, so that on holding the developed plate
up to the light a dense deposit is seen in those parts representing
the brightest portions of the subject, while the shadows of the
original are represented by thin areas, and the half-tones by deposits
of intermediate density. For this reason the developed plate is
called a negative. The plate is then bathed in a solution of sodium
thiosulphate (generally called “hypo”), which dissolves the unaffected
silver salt but does not affect the metallic silver--or at least does
so only very slowly. Next, the plate is washed in water to remove all
unnecessary chemicals, and is dried. The ordinary plate is sensitive
only to ultra-violet (invisible) and violet light, so it cannot
render truthfully any subject having color, but by the addition of
certain aniline dyes to the emulsion it may be rendered sensitive to
green in addition to violet and ultra-violet; it is then described as
orthochromatic (“right-”) or isochromatic (“equally-”).
Still other dyes extend the sensitiveness to include not only
ultra-violet but also the entire visible spectrum; such a plate is
called pan-chromatic (“all-”).

[Illustration: From a photograph by Paul L. Anderson

A PORTRAIT PHOTOGRAPH]


_Printing the Photograph_

The finished negative, when dry, must of course be printed, and there
are many printing mediums available. The carbon process gives an image
in lamp-black or some earth pigment, bound up in a film of gelatine;
the gum-pigment process gives an image similar to that of carbon, the
binder in this case being gum arabic; the platinum process gives an
image of black metallic platinum direct on the paper support. Other
processes give different effects, one of the most valuable to the
pictorial worker being gum-platinum, in which a completed platinum
print is coated with a gum-pigment film and printed under the negative
a second time, the final result being a gum-pigment image superposed
on the platinum image. Of all printing mediums the one that has most
intrinsic beauty, and is at the same time most capable of rendering
satisfactorily the gradations of the negative, is probably platinum,
so this is most used by pictorial workers. But, since it is expensive
and requires daylight or strong artificial light for printing, nearly
all commercial workers prefer the somewhat less beautiful and less
permanent, but more convenient, gas-light paper, so-called because
it can be manipulated entirely by gas-light, neither daylight nor a
dark-room being required. This medium consists of paper that has been
coated with an emulsion somewhat similar to that used for plates, but
requiring much longer exposure. The negative is placed in an appliance
that holds it in close contact with the paper, then a sheet of paper
is put in, and an exposure of a few seconds is given. Obviously, the
paper receives most light under the thin parts of the negative and less
under the denser portions, so that when the print is developed, fixed,
washed and dried the resulting picture is light where the original
subject was light, dark where that was dark, and show intermediate
gradations where these existed in the original.

[Illustration: Photograph by Karl Struss

CAPRI, ITALY]

[Illustration: From a bromoil transfer by Charles Kendall

THE SHADOW OF A SIGN]

For purposes of reproduction two processes depending on photography
have almost entirely superseded the older methods of etching and wood
engraving. These photo-mechanical processes, as they are called, are
far more rapid and much cheaper, and are, in addition, more accurate.
In photo-gravure the photographic image--copied by photographing
the original--is transferred to a copper plate and the plate is
automatically etched in an acid bath to varying depths, depending on
the depth of shadow in the original. This plate is then inked all
over, the ink being worked into the depressions in the copper, and the
surface ink wiped off. A sheet of paper is brought into contact with
the plate under heavy pressure, and, being forced into the hollows of
the copper and taking up the ink from them, a print results. In the
less beautiful but cheaper and more rapid half-tone process the copy is
made through a cross-ruled glass screen, the image being thus broken up
into a series of dots. The image so obtained is transferred to a zinc
plate, which is etched in an acid bath or with an acid spray. The dots
serve to protect the zinc from the action of the acid.[A] The finished
plate shows an image consisting of dots with hollows between them, the
dots being large and near together in the shadows, small and far apart
in the lights. This plate is inked with a roller, and a sheet of paper,
lightly pressed against it, takes up the ink to form a print. Thus it
will be seen that photo-gravure is an intaglio (cut-in) process, and
half-tone a surface-printing process.

[A] See cut on page 9.


_Photographic Illustrations_

[Illustration: From a platinum print by W. E. Macnaughton

SCENE ON THE CONNECTICUT RIVER]

Photography has not only superseded manual processes for reproduction,
but has also largely replaced them for purposes of illustration.
Practically all news illustrations are now made by photography, which
is also extensively used for advertising work. To a less extent it is
employed for fiction illustration, admirable work having been done in
this field by Clarence H. White, Karl Struss, and Lejaren à Hiller. It
does not, however, seem probable that photography will ever entirely
replace draughtsmanship for the illustration of fiction, since the very
strength of the camera,--that is, its surpassing power of rendering
accurately the outlines and gradations of natural objects,--operates
as a severe limitation in the case of original, imaginative work.
It is difficult to conceive of “The Fall of the House of Usher” or
“The Rime of the Ancient Mariner” being satisfactorily illustrated by
photography, and if, for instance, “Le Morte d’Arthur” were made a
photographic subject, the cost of models, costumes and scenery would
probably be excessive.

[Illustration: From a carbon print by H. Y. Sümmons

“THE STYGIAN SHORE”]

Despite the limitations of the camera as regards imaginative work there
is a small but devoted band of photographers who use the camera as a
means of artistic expression, and these men and women have produced
some wonderfully fine results that fulfil the definition of art: “A
means of arousing an emotion in the spectator.” In the last analysis,
however, it will be found that such results are due to one of two
methods of approach: either the careful selection of an unusual natural
effect, or the use of one of the so-called “control processes”--that
is, printing mediums that allow the worker to modify at will either
the outlines or the gradations of the negative, or both. In the former
case, however, the photographer cannot be regarded as more than an
exceptionally sensitive and perceptive craftsman, and in the latter
instance the camera user, of course, ceases to be a photographer and
becomes a creative artist, using photography merely as a basis on which
to construct an imaginative result. The possibilities of this second
method of work have not yet been fully explored; they appear to be
limitless.


_The Precision of Photography_

[Illustration: Photograph by Struss

AFTERNOON SUN

The Biltmore, New York]

[Illustration: Photograph by Struss

A MISTY DAY

Chatham Square, New York]

[Illustration: Photograph by Struss

SUNSHINE AND SHADOW

Park Row, New York]

[Illustration: Photograph by Struss

SUNLIGHT ON SURF]

The literalness of photography, which prevents its ever competing
with etching or painting in imaginative art, makes it of inestimable
value in certain realms, and scientists of all sorts, astronomers,
physicists, physicians, pathologists, as well as architects, building
contractors, business men, who wish a precise and accurate record of
any object, recognize the value of the camera. Photographs are often
admitted as legal evidence in court. It is impossible to overstate the
value of the dry-plate to the surgeon, since the X-ray, generated by
passing an electric discharge through a glass tube from which most of
the air has been exhausted, penetrates many objects that are opaque
to ordinary light, and, though invisible to the eye, nevertheless
affect a photographic plate, thus making possible a precise diagnosis
of fractured bones, gun-shot wounds, digestive disturbances, and many
other pathological conditions in which diagnosis without a radiograph
would be mere guesswork.

In portraiture, photography is superior to any other graphic art, since
the camera worker can, by judicious selection of lighting, pose and
facial expression, render the character of the sitter quite as well as
the draughtsman, this being the final test in portrait work, though it
must be admitted that few portrait photographers meet this requirement.


_Microphotography_

[Illustration: By Paul L. Anderson

PHOTOGRAPH TAKEN IN A SNOWSTORM

New York]

The human eye and mind are, from a mechanical point of view, but
imperfect instruments. Admirably as they serve the purpose for which
they are designed, it is nevertheless impossible for them to observe
with absolute accuracy. The camera, however, has no such limitations;
its observations are accurate and its records unquestionable, so long
as no definite effort is made to impair their exactness. For this
reason photography is used not only in astronomy but in many other
branches of science, among its most important uses being the making of
records of microscopic objects.

A device carrying a photographic plate is attached to the eye-piece
of a microscope; the plate being exposed affords, on development,
a precise record of the subject under observation. It may be noted
that in this case, as in astronomical photography, no camera lens is
required; the microscope, like the telescope, projects an aërial image
which is impressed on the plate. It thus becomes possible for the
microscopist to study at leisure a photograph of the object that was
in the field of the microscope, and thereby eliminate eye-strain and
minimize the likelihood of overlooking any feature of interest. It is
further possible to make lantern-slides from the negative so obtained.
A lecturer by this means is enabled to show the photograph to a large
group of individuals simultaneously.

[Illustration: Photograph by Struss

By courtesy of Cleveland Metal Products Co.

ADVERTISING ILLUSTRATION

An example of commercial photography]

[Illustration: THUMB-PRINT ON DARK WOOD

Finger-prints are made visible by dusting with a fine powder, and are
photographed with a special detective camera]

Though the photographic plate thus extends the usefulness of the
microscope, this is not the limit of its value in this respect.
Light is transmitted by waves, similar in some ways to waves in
water, the light waves being disturbances of the light-bearing ether,
an invisible, imponderable substance of zero density and infinite
elasticity, which pervades all matter. (It must be understood that
the ether has never been observed nor its actual existence proven; it
is, however, a necessary assumption for the satisfactory explanation
of the observed phenomena of light, so far as our present knowledge
extends.) The distance from the crest of one wave to the crest of the
next is known as the wave length, the lengths of the various light
waves having actually been measured. The human eye is sensitive only to
waves between about four-ten-thousandths and seven-ten-thousandths of a
millimeter in length, a millimeter being about one-twenty-fifth of an
inch, and an object is invisible in the microscope if its diameter is
less than half the wave length of the light by which it is illuminated,
since in that case the light waves bend around the object and meet
on the other side. We cannot, therefore, see objects whose diameter
is less than about two-ten-thousandths of a millimeter. But the
photographic plate is sensitive to shorter waves than the eye; these
waves are known as the ultra-violet. By illuminating the microscope
stage with ultra-violet light it therefore becomes possible to
photograph objects so small that they must forever remain invisible to
the naked eye, unless, indeed, the progress of human evolution brings
with it increased sensitiveness to the shorter wave lengths. In this
connection it is interesting to note that there are organisms so small
that they cannot be made apparent to us even by photography, though
we are made aware of their existence by inductive reasoning from their
observed effects.

[Illustration: NEWSPAPER ILLUSTRATION

Enlarged to show half-tone screen]

In the case of some objects, a fuller knowledge of their character is
gained if they are examined in a manner somewhat different from that
usually adopted. One of the photographs given herewith shows the effect
obtained by what is known as “dark ground illumination.” Ordinarily,
the light by which a microscopic object is examined passes through the
slide, so that an opaque object is really seen only as a silhouette,
but in dark ground illumination an opaque background is placed behind
the object, and the light is allowed to fall on it from the sides. The
object is thus made visible by the light that is refracted (that is,
bent) into the lens of the microscope. In the present instance the
effect seen by looking into the eye-piece was wonderfully beautiful,
the crystals glowing with a brilliant yellow light against an intensely
black ground.


_Radiography_

Some persons object to the inclusion of radiography as a branch of
photography, since no camera or lens is used, but “photography” means,
literally, “light-writing,” and radiography is precisely this.

If the air be nearly exhausted from a glass tube, so that a high vacuum
exists therein, and it be then sealed up, a current of electricity may
be sent through the remaining air, setting up ether vibrations that
pass out from the tube. These ether waves have the power of passing
through many substances that are opaque to visible light, the X-rays,
as they are termed, being totally invisible, though light waves to
which the eye is sensitive are set up at the same time within the tube.
Many persons confuse the greenish light from an X-ray tube with the
X-rays, but the two are actually entirely different manifestations. The
X-rays, though invisible to the eye, are nevertheless able to affect a
photographic plate strongly, so that photographs may be made through
solid objects. For example, if a sensitive plate be laid on a table and
the arm or the hand placed on it, and an X-ray tube is brought near the
arm, a photograph results in which the bone is represented as a dark
area and the flesh around it as lighter, this being, of course, simply
a shadow picture. This affords an intensely valuable aid to diagnosis,
and a good surgeon will, if possible, first radiograph a fractured bone
before setting it, unless the circumstances are very exceptional.
The value of radiography is not, however, confined to fractures, but
extends to wounds (it is of great help in locating metallic fragments
or other foreign bodies in a wound), to many intestinal disorders, and
to the diagnosis of other diseased conditions.

[Illustration: STRIP OF MOTION-PICTURE FILM

Actual size. The photography consumed five-eighths of a second, or just
long enough for the subject to turn her head]

[Illustration: By courtesy of W. Faitoute Munn

MICROPHOTOGRAPH OF CRYSTALS OF BRUCINE SULPHATE

(A) By transmitted light

(B) With dark-ground illumination]

Though not strictly bearing on photography, it is interesting to
note that the X-rays, like the “gamma rays” (γ-rays) of radium, are
in reality ether vibrations of very short wave length, and like the
shorter waves (the ultra-violet) in sunlight, possess curative powers
in some skin disorders and also the power of causing terrible burns.
Sunburn does not result from exposure either to visible sunlight or to
the heat of the sun, but to the ultra-violet rays; and an X-ray burn is
identical with sunburn. In extreme cases the X-rays may cause complete
destruction of the skin and even cancer, and before the properties of
the X-rays were so well known as at present many operators lost hands,
and some their lives, as a result of excessive exposure to the rays.
At present, X-ray workers shield themselves, and, when necessary, the
patient, with lead screens, that metal being practically opaque to the
rays.


_Color Photography_

Many workers have tried, with varying success to devise a means whereby
photography could be made to reproduce not only the outlines and
gradations of natural objects but the colors as well, and there is
now available a method of great worth for this purpose. In brief, it
consists in making, by one exposure in an ordinary camera, a set of
three-color negatives, each of which represents that portion of one
of the primary colors--violet, green and red--which was reflected from
the subject. That is, one negative represents the violet “sensation,”
the second the green, and the third the red. Prints are made from these
negatives in suitable dyes on transparent films, which are cemented
together, one over the other, thus giving a true color photograph,
in which the secondary and tertiary colors--blue, yellow, orange,
purple, brown, etc.--are obtained, as in painting, by the mixture
in proper proportions of two or more of the primaries. This is the
first method of color photography to possess the great advantage of
producing prints--not transparencies, so that any number of duplicates
may be made. No special camera is required, and the process is within
the reach of any careful amateur. The writer believes the artistic
value of color photography is relatively slight--a black and white
art is capable of the fullest intellectual expression, and color is
merely sensuous in its appeal. After much experiment with different
color processes, he finds his own monochrome (single tone) prints
more satisfying than the color work. However, the value of color to
the scientific worker is incalculable, as will be realized at once on
considering only one of the possible applications--namely, the study of
skin affections. It is interesting to note that several methods have
been devised for the reproduction of natural colors in motion-picture
work--the familiar method of coloring the positive film by hand being
only an approximation to truth. But none of those presented up to this
time is fully satisfactory, though the prospects of future development
are good.

When we consider the manifold and widespread uses of photography and
the pleasurable diversion that it affords, it seems safe to say that
there is no other form of industry not an actual necessity that is of
such importance to the welfare and happiness of the human race.

[Illustration: By courtesy of Dr. T. W. Harvey

RADIOGRAPH OF NORMAL HAND]


_SUPPLEMENTARY READING_

  PICTORIAL PHOTOGRAPHY, PRINCIPLES AND PRACTICE     _By Paul L. Anderson_
  INSTRUCTION IN PHOTOGRAPHY                  _By Sir William de W. Abney_
  SCIENCE AND PRACTICE OF PHOTOGRAPHY                 _By John R. Roebuck_
  PHOTOGRAPHY OF TODAY                                    _By H. C. Jones_
  THE ARTISTIC SIDE OF PHOTOGRAPHY                     _By A. J. Anderson_

⁂ Information concerning the above books may be had on application to
the Editor of The Mentor.




_THE OPEN LETTER_


One summer afternoon, some years ago, I went into a front room of my
home and drew down the window shades to shut out the glare and heat.
The room became quite dark, but, in one of the shades, there was a
small hole, through which the sunlight penetrated--casting on the white
wall opposite, vivid images of all the objects in the street outside. I
had before me a full-color, moving picture of the panorama of life that
was passing the window.

Here was the original “camera obscura” (“dark chamber”). If one placed
in the small hole in the shade a glass lens to give a sharp image,
and substituted for the wall a movable screen, on which the projected
objects could be focussed, one would have the essential elements of a
modern camera. Through just such simple experiences as this important
scientific discoveries are sometimes made.

       *       *       *       *       *

For many years photography was largely confined to portraiture and the
faithful reproduction of objects and scenes. All that was expected of a
camera was to “make a picture” of a thing. Within the last forty years,
however, as reproductive processes have been invented, photography has
come to be one of the most useful of arts. Beginning about 1883, the
quality and character of the illustrations in our magazines and books
changed radically. Where, previously, there had been nothing but hand
engravings of one sort or another, _photo-engraving_ appeared, and,
with that, the horizon of magazine illustration extended far beyond the
reach of the liveliest imagination. Who could have foreseen, then, in
the first photo-engraving processes, such possibilities as photographic
printing in full colors, or moving picture films? Today, pictorial
illustration depends on photography, and there is apparently little
or nothing in life beyond the reach of photographic art. It discloses
the internal arrangements of human anatomy; it makes a record of the
affairs of the heavenly bodies; it pictures things that the human eye
cannot see; it is even potent in the realm of mystery, for have we not
seen photographs of ghosts(?) reproduced from spirit seances? When
objects and situations in life that do not exist are wanted, the camera
can, by some trick or device, create them for us. There seems to be
no limit to the possibilities. Each wonder displayed in photographic
reproduction gives way to some new effect more wonderful still.

       *       *       *       *       *

Consider briefly a few of the wonders of modern photography. First and
foremost, and most spectacular of all, is the moving-picture film.
Then, in the world of practical things, we have the telephoto-lens--a
combination of the telescope and camera--that takes pictures of objects
far beyond the reach of the naked eye. This enables one to photograph
the head of a gargoyle on a distant cathedral, or the fledglings in an
eagle’s nest, or a mountain goat on a crag high up a mountain side.
Then there is the swinging camera, by means of which a wide sweep of
view can be included in one plate. A device of great practical value
is photo-telegraphy, by which portraits for purposes of identification
can be sent by cable and by wireless. In modern warfare the uses of
the camera are many and varied. They include panoramic photography,
photographing by moonlight, photographing of projectiles in the air,
even photographing the noise of a gun by recording the vibrations due
to the displacement of the air, photo map-making, photo surveying
from the air, and the aviation gun camera. Radiography, too, must be
mentioned--the X-ray and its use in surgery.

       *       *       *       *       *

While all these wonders have come to pass in practical service,
photography has likewise grown and expanded in the field of fine art.
There are photographic art schools, and clubs and exhibitions--all
for the purpose of cultivating and developing the camera to the
finest forms of expression. We have highly cultivated and skilled
photographers who are true artists, and who are engaged in employing
photography as a means to fine art achievement. Among such artist
photographers in this country mention should be made of Mr. Paul L.
Anderson--the author of the present article; Arnold Genthe, who,
besides his wonderful portraits, has, by his art, preserved for future
generations the scenes of old San Francisco--especially Chinatown--that
have now passed away; Gertrude Käebier, Baron de Meyer and Jan de
Strelecki, Stieglitz, Eyckmeyer, Steichen, Sümons and so many others
that the list would fill this page.

[Illustration: W. D. Moffat

EDITOR]




What, Who, and When?


WHAT IS PHOTOGRAPHY?

It is the science and art of producing pictures by the action of light
on chemically prepared (sensitized) plates or films.

WHO DISCOVERED PHOTOGRAPHY?

No one particular individual. There is no known date on which
“photographic action” was first recorded. The action of the sun in
making impressions of one sort or another on surfaces was known to
man from the earliest times. Records of it can be seen in fossilized
vegetable remains--and this action of the sun is apparent in the change
of color that takes place in the ripening of fruits and foliage.

WHO FIRST APPLIED A SENSITIZED PLATE TO THE PURPOSE OF MAKING
PHOTOGRAPHIC PRINTS?

No single individual discovered this essential principle of
photography. It came to be recognized in the course of many
experiences, beginning with the alchemists; and developing through
the experiments of a number of investigators, until the end of the
eighteenth century, when the sensitiveness of various silver compounds
to light became well known, and the character of the change produced
on these compounds by light became established. Thomas Wedgwood, the
fourth son of Josiah Wedgwood, the renowned potter, developed a process
by means of which the image printed by photographic means could be
“fixed” and made permanent.

WHAT INSTRUMENT BROUGHT THE PHOTOGRAPHIC PROCESS TO A PERFECTED FORM?

The camera. The camera is the photographic apparatus in which the image
is projected upon the sensitized plate, thus securing a photographic
impression. The word “camera” is Italian for “room,” and the full name
of the original instrument, “camera obscura,” means “dark room.”

WHO INVENTED THE CAMERA?

Giovanni Baptista della Porta, who lived in the sixteenth century, has
often been stated to have invented the camera, but he appears only to
have popularized and improved it. The first use of cameras was not for
printing photographs, but simply as an interesting toy or to assist one
in tracing the outlines of various objects. There are many applications
of the “camera obscura”--a notable one being the periscope of a
submarine. It was not until a suitable sensitive plate was discovered
that the camera became useful as an apparatus of photography.

WHO WERE MOST PROMINENTLY IDENTIFIED WITH THE DEVELOPMENT OF THE
PHOTOGRAPHIC PROCESS?

Joseph Niépce and Louis J. M. Daguerre. Niépce was successful not
only in getting pictures produced in the camera, but he succeeded
in “fixing” them permanently, Daguerre developed a process known as
“daguerreotype,” which was the first method of photography available
for practical purposes. This was in 1837. With the general acceptance
of daguerreotypes, photography became a profession. The process had no
rival until about 1851, when the “collodion process” was discovered,
and, after that, the daguerreotype process became obsolete.

WHO DEVELOPED THE MODERN PROCESS OF PHOTOGRAPHY?

William Henry Fox Talbot, an English inventor (1800-1877). He greatly
increased the sensitiveness of paper, and from his negatives prints
were produced in much the same way as in the present day.




THE MENTOR

The Wealth of The Mentor


      1 Beautiful Children in Art, by Gustav Kobbé.
      2 Makers of American Poetry, by Hamilton Mabie
      3 Washington the Capital, by Dwight Elmendorf.
      4 Beautiful Women in Art, by Willing.
      5 Romantic Ireland, by Elmendorf.
      6 Masters of Music, by Henderson.
      7 Natural Wonders of America, by Elmendorf.
      8 Pictures We Love to Live With, by Huneker.
      9 The Conquest of the Peaks, by Fay.
     10 Scotland, the Land of Song and Scenery, by Elmendorf.
     11 Cherubs in Art, by Kobbé.
     12 Statues with a Story, by Lorado Taft.
     13 The Discoverers, by Albert Bushnell Hart.
     14 London, by Elmendorf.
     15 The Story of Panama, by Bonsal.
     16 American Birds of Beauty, by E. H. Forbush.
     17 Dutch Masterpieces, by Van <DW18>.
     18 Paris, the Incomparable, by Elmendorf.
     19 Flowers of Decoration, by H. S. Adams.
     20 Makers of American Humor, by Burges Johnson.
     21 American Sea Painters, by Arthur Hoeber.
     22 The Explorers, by Albert Bushnell Hart.
     23 Sporting Vacations, by Dan Beard.
     24 Switzerland, the Land of Scenic Splendors, by Elmendorf.
     25 American Novelists, by Hamilton Mabie.
     26 American Landscape Painters, by Samuel Isham.
     27 Venice, the Island City, by Elmendorf.
     28 The Wife in Art, by Kobbé.
     29 Great American Inventors, by Bruce.
     30 Furniture and Its Makers, by Richards.
     31 Spain and Gibraltar, by Elmendorf.
     32 Historic Spots of America, by McElroy.
     33 Beautiful Buildings of the World, by Ward.
     34 Game Birds of America, by E. H. Forbush.
     35 The Contest for North America, by A. B. Hart.
     36 Famous American Sculptors, by Lorado Taft.
     37 The Conquest of the Poles, by Rear Admiral Peary.
     38 Napoleon, by Ida M. Tarbell.
     39 The Mediterranean, by Elmendorf.
     40 Angels in Art, by Van <DW18>.
     41 Famous Composers, by Henry T. Finck.
     42 Egypt, the Land of Mystery, by Elmendorf.
     43 The Revolution, by Albert Bushnell Hart.
     44 Famous English Poets, by Mabie.
     45 Makers of American Art, by J. T. Willing.
     46 The Ruins of Rome, by Botsford.
     47 Makers of Modern Opera, by H. E. Krehbiel.
     48 Two Early German Painters--Dürer and Holbein, by F. J. Mather, Jr.
     49 Vienna, the Queen City, by Elmendorf.
     50 Ancient Athens, by Botsford.
     51 The Barbizon School, by Hoeber.
     52 Abraham Lincoln, by A. B. Hart.
     53 George Washington, by McElroy.
     54 Mexico, by Frederick Palmer.
     55 Famous American Women Painters, by Arthur Hoeber.
     56 The Conquest of the Air, by Woodhouse.
     57 Court Painters of France, by Coffin, N. A.
     58 Holland, by Elmendorf.
     59 Our Feathered Friends, by E. H. Forbush.
     60 Glacier National Park, by Hornaday.
     61 Michelangelo, by Cox.
     62 American Colonial Furniture, by Esther Singleton.
     63 American Wild Flowers, by Eaton.
     64 Gothic Architecture, by Ward.
     65 The Story of the Rhine, by Elmendorf.
     66 Shakespeare, by Mabie.
     67 American Mural Painters, by Hoeber.
     68 Celebrated Animal Characters, by Hornaday.
     69 Japan, by Elmendorf.
     70 The Story of the French Revolution, by Albert Bushnell Hart.
     71 Rugs and Rug Making, by Mumford.
     72 Alaska, by Browne.
     73 Charles Dickens, by Mabie.
     74 Grecian Masterpieces, by Lorado Taft.
     75 Fathers of the Constitution, by Albert Bushnell Hart.
     76 Masters of the Piano, by Finck.
     77 American Historic Homes, by Singleton.
     78 Beauty Spots of India, by Elmendorf.
     79 Etchers and Etching, by Weitenkampf.
     80 Oliver Cromwell, by Albert Bushnell Hart.
     81 China, by Elmendorf.
     82 Favorite Trees, by Hornaday.
     83 Yellowstone National Park, by Elmendorf.
     84 Famous Women Writers of England, by Mabie.
     85 Painters of Western Life, by Hoeber.
     86 China and Pottery of Our Forefathers, by Esther Singleton.
     87 The Story of The American Railroad, by Albert Bushnell Hart.
     88 Butterflies, by Holland.
     89 The Philippine Islands, by Worcester.
     90 Great Galleries of the World--the Louvre, by Van <DW18>.
     91 William M. Thackeray, by Mabie.
     92 The Grand Canyon, by Elmendorf.
     93 Architecture in American Country Homes, by Aymar Embury.
     94 The Story of the Danube, by Albert Bushnell Hart.
     95 Animals in Art, by Kobbé.
     96 The Holy Land, by Elmendorf.
     97 John Milton, by Mabie.
     98 Joan of Arc, by Ida M. Tarbell.
     99 Furniture of the Revolutionary Period, by Esther Singleton.
    100 The Ring of the Nibelung, by Finck.
    101 The Golden Age of Greece, by Botsford.
    102 Chinese Rugs, by Mumford.
    103 The War of 1812, by Albert Bushnell Hart.
    104 Great Galleries of the World--The National Gallery, London,
        by Van <DW18>.
    105 Masters of the Violin, by Finck.
    106 American Pioneer Prose Writers, by Mabie.
    107 Old Silver, by Esther Singleton.
    108 Shakespeare’s Country, by William Winter.
    109 Historic Gardens of New England, by Mary H. Northend.
    110 The Weather, by C. F. Talman.
    111 American Poets of the Soil, by Johnson.
    112 Argentina, Newman.
    113 Game Animals of America, by Hornaday.
    114 Raphael, by Van <DW18>.
    115 Walter Scott, by Mabie.
    116 The Yosemite Valley, by Elmendorf.
    117 John Paul Jones, by Albert Bushnell Hart.
    118 Russian Music, by Finck.
    119 Chile, by Newman.
    120 Rembrandt, by Van <DW18>.
    121 Southern California, by C. F. Lummis.
    122 Keeping Time, by Talman.
    123 American Miniature Painting, by Mrs. Elizabeth Lounsbery.
    124 Gems, by Esther Singleton.
    125 The Orchestra, by Henderson.
    126 Brazil, by E. M. Newman.
    127 The American Triumvirate, by A. B. Hart.
    128 The Madonna and Child in Art, by Van <DW18>.
    129 The Story of the American Navy, by Barnes.
    130 Lace and Lace Making, by Esther Singleton.
    131 American Water Color Painters, by Kobbé.
    132 Peru, by E. M. Newman.
    133 The Story of the American Army, by Hart.
    134 Our Planet Neighbors, by Harold Jacoby.
    135 The Story of Russia, by Leo Pasvolsky.
    136 The Story of the Hudson, by A. B. Hart.
    137 Prehistoric Animal Life, by Dr. Matthew.
    138 Hawaii, by E. M. Newman.
    139 Earthquakes and Volcanoes, by Talman.
    140 The Canadian Rockies, by Ruth Kedzie Wood.
    141 Corot, by Elliott Daingerfield.
    142 Bolivia, by E. M. Newman.
    143 Russian Art, by William A. Coffin.
    144 The American Government, by A. B. Hart.
    145 Christmas in Picture and Story, by Singleton.
    146 The Picture on the Wall, by Weitenkampf.
    147 Lafayette, by Albert Bushnell Hart.
    148 American Composers, by Henry T. Finck.
    149 The Luxembourg Gallery, by Wm. A. Coffin.
    150 Julius Caesar, by Prof. George W. Botsford.
    151 The Incas, by Osgood Hardy.
    152 Rodin, by Emile Villemin.
    153 The Columbia River, by Ruth Kedzie Wood.
    154 The Story of Coal, by C. F. Talman.
    155 Benjamin Franklin, by A. B. Hart.
    156 The Forest, by Henry S. Graves.
    157 Metropolitan Museum of Art, by S. P. Noe.
    158 The Cradle of Liberty, by A. B. Hart.
    159 Rainier National Park, by Belmore Browne.

You need only mail a post card--listing ten or more of the numbers
opposite the titles--and we will send the selections of your choice,
all charges paid. Ten copies, at 20 cents each, may be paid for on easy
installments of but $1.00 a month for two months. We urge you to mail
the card to us today.

THE MENTOR ASSOCIATION, 114-116 East 16th Street, New York City

MAKE THE SPARE MOMENT COUNT





End of the Project Gutenberg EBook of The Mentor: Photography, Vol. 6, Num.
12, Serial No. 160, August 1, 1918, by Paul L. Anderson

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