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The Railroad Photographs


Alfred A. Hart, Artist


Edited by Peter E. Palmquist

The California State Library Foundation Sacramento, California

Copyright © 1995 by California State Library Foundation
All rights reserved. No part of this book may be reproduced in any form without written permission from the publisher.

ISBN 0-929722-85-X

Printed in the United States of America

Alfred A. Hart, Artist

Table of Contents

Editor's Foreword IX

Author's Preface XI

Introduction and Brief History of the Construction

of the Central Pacific Railroad 15

Starting The Railroad 18

Judah's Death at 37 22

CPRR Tunneling Methods 25

Nitroglycerin Adventures 28

Building the World's Longest Barn 33

Racing to Utah 35

Crocker's Bet to Lay Ten Miles in One Day 36

A Day of National Rejoicing 39

The Problem of Local Time 43

Photographing at Promontory 44

Notes on railroad books and appendixes 45

Alfred Hart: Photographer, Author and Publisher 51

Dating Hart's RR Construction Stereos 54

Dating Stereos with Tax Stamps 60

Dates the CPRR reached various points 62

The Fate of Hart's CPRR Negatives 69

Hart's years after 1869 73

Hart's Photographic and Production Methods 79

Methods in the Field 79

Light Sensitive Materials 80

The Wet Collodion Process 81

Necessary Ingrediants 82

Preparing The Plates for Exposure 84

Developing and Fixing the Negative 85

Hart's Camera and Equipment 89

Shutters 95

Stereograph Production 96

Making Stereo Prints 96

Sensitizing the Paper and

Printing the Negative 99

Masking 100

Toning, and Fixing the Prints 102

Transposing 103

Title Strips 104

Viewing Stereographs 105

Looking for the Photographer 109

Hart's Non-Railroad Photographs 111


A Reproductions of Hart's CPRR Stereo Views 113

B Numerical List of Hart's CPRR Stereo Views 153

C Geographical List of Hart's CPRR Stereos 167

D Public Sources of Hart's CPRR Stereo Views 177

E Glenn Willumson's Article on Hart 187

F Transposing and some Stereo Camera Details 203

G Replicas of somePages of Hart's Travel Book 213

Reading List and Short Bibliography 231

Index 233

List of Illustrations 238

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This section will focus on the way a photographer of the 1860s took stereo views--particularly Hart's methods--where they can be deduced from the surviving prints. Information is included about photosensitive materials Hart used, problems peculiar to stereo photography, Hart's equipment, and the production of the finished stereo cards.

The technical side of photography, including stereo or three-dimensional imaging, has long attracted the interest of great scientific minds. Enjoyable as it would be to have such an expert explain Hart's photographic techniques, the following remarks are written mainly from a practical standpoint. Consequently, they may not answer all of the questions which would occur to a reader, but the facts given should provide a basis for additional research.


Hart's energetic approach and almost total disregard for his personal safety while taking photographs is not immediately apparent in every CPRR stereo, but it is clearly demonstrated in a number of his views. In fact, getting his heavy camera and tripod to high places to record scenes from the tops of locomotives, box cars, and various cliffs were almost his trademark.

An especially large number of Hart's CPRR views in Nevada and Utah are taken from the tops of boxcars which required climbing a narrow vertical ladder. Likewise the difficulties in getting from the tracks to the camera location at the very top of the Palisades (No. 340) must have been a story in itself.

As he grew older and the railroad progressively longer, Hart seemed to become rather more conservative about climbing on locomotive cabs. From Lost Camp Spur (No.162) at 80 miles from Sacramento to Promontory Point (No. 357) at 690 miles, he published no photographs taken from the roof of a locomotive cab. However, this may have had far less to do with his declining agility and more to do with the locomotive engineers objecting to leaky cab roofs caused by the sharp points on the legs of Hart's camera tripod (See Fig. 66 p. 94).

Hart clearly understood the great importance of placing his stereo camera at an elevated position in order to de-emphasize uninteresting foreground areas that might result from his relatively wide-angle lenses. For example, No. 242, "West of Clipper Gap", when viewed as a single image initially appears to have been taken from the level of the roadbed alongside the track. Examined in stereo, it is seen that the camera and the standing man are actually about 20 feet above the rails. Hart, unfortunately ignored this rule at Promontory in No. 360, "The Last Act", with rather disastrous result. More likely he remembered the rule, but hadn't brought a ladder such as the one seen at the left background in No. 357 and employed by the Union Pacific photographer, A. J. Russell, to take his world-famous "Handing the bottles" view of the two locomotives meeting.

A century and a quarter later, by carefully lining up the road bed with distant features of the landscape and correcting for differences in field-of view, it is still possible to find in many cases the exact point where Hart set his tripod. After personally locating dozens of such sites, it is easy to state that Alfred Hart was quite literally something of a tough act to follow.

In stereo photography, in order that the eye and brain can work the miracle of depth perception, two images must be taken, usually with about the same separation as human eyes -- about 2-5/8 inches. Occasionally with larger formats, greater separation was employed, and a smaller separation for close-up stereo photography. For non moving objects the two images can be taken with a single lens camera if it is shifted latterly the appropriate distance between exposures. In normal work, where the two images were taken on a single negative at the same instant, a special camera equipped with two lenses was required (Fig. 58.) All of Hart's stereos appear to have been taken with such special cameras. An experienced stereo photographer tended to seek camera locations that would exploit the camera's ability to record depth. Interiors of snowsheds, tunnels, and bridges were obvious targets.

With lenses only inches apart, the stereo camera could not differentiate the distance between objects located near the horizon on the Nevada desert, or the separation between mountains in the next range in the Sierra. Such scenes could be vastly improved by including something distinctive, or dramatic in the immediate foreground, usually within 15 feet of the lens.

For Hart the unbeatable "something" was the top of a locomotive boiler, or the railroad rails traversing a cliff near his camera with a valley far below.


In the 1860s, when Hart was first taking his railroad views, the pioneer daguerreotype method had already declined in popularity and the wet collodion process was in vogue. This involved carrying glass plates which were, just before use, coated with iodized collodion (a viscous mixture of gun-cotton dissolved in alcohol and ether) and sensitized by dipping in a silver nitrate solution. The final step had to be done in a dark tent (described at end of Appendix F) by the dim light from a small translucent panel of yellow or orange silk.

Coating, sensitizing, exposing, and developing had to be completed before the plate dried, in a total period of five to ten minutes (depending on temperature and humidity), or the plate would lose sensitivity. In addition to leaving the camera looking as if one had been cleaning fish in it, the sensitizing and developing procedures stained the operator's hands; and the plates, both before and after exposure, were heavy and fragile. Photographers utilized this messy process because the resulting negatives displayed a beautiful long tonal range, required a shorter exposure than the earlier methods, and could be used to make any number of positive paper prints.

While it appears that no Hart negatives have survived to this day, it is possible to estimate their size as 5 inch by 8-inch from a wonderful collection of contact prints at the Society of California Pioneers in San Francisco and from other contemporary wet-plate cameras which generally employed the 5-inch by 8-inch format.

Such glass plates were 1/16-inch thick and weighed three and one half ounces each, or two and one half pounds per dozen (the normal number in the portable plate box).


This revolutionary photographic method, referred to as the "wet-plate process" was invented in 1851 by Frederick Scott Archer. A butcher's son, Archer was born in 1813 in Hertfordshire, England, and later became a London portrait sculptor. To assist him in this work, he used calotype (paper negative) photography, but vastly improved upon it by using the newly-invented collodion on glass as a substitute for the paper support. The layer of collodion was very thin relative to paper and was as transparent as glass. Properly formulated collodion adhered tightly to the glass base, but unfortunately collodion which had dried (by the evaporation of the alcohol and ether solvents) was impermeable to water. This prohibited the introduction of the water-based compounds needed to develop and fix the latent image.

Archer's stroke of genius was the concept of completing the sensitizing, exposure and development of the negative before the collodion had dried, possibly because the developer was now allowed to enter the spaces occupied by the alcohol molecules. The result was a revolution in photography that lasted over 30 years. Archer's process was easier and cheaper, had an effective film speed that was at least ten times that of the daguerreotype and the retention of details almost equalled the earlier process. The main advantage of the new technique was that any number of fine paper prints could be made from the same transparent negative.

Archer made a related invention in 1852 called the positive collodion process. In an "ambrotype," as they were named in America, the collodion was made thinner, the deposited metallic silver was whitened with bi chloride of mercury, and the glass negative was blackened on the back to make an image which appeared positive. Within a few short years of its introduction in 1854, the ambrotype had largely replaced the daguerreotype for popular portraiture. The tintype or melainotype used a similar process, but employed a blackened sheet of iron as the base. In California, portraits were also occasionally produced on black leather, or oilcloth because they could be carried or mailed without danger of breaking.

Frederick Scott Archer published his wet-collodion process in 1851 without asking any compensation and was rewarded shortly thereafter by being named the defendant in a law suit filed by William Henry Fox Talbot, claiming this was all just a copy of his calotype process. The case was dismissed, but Archer died in poverty on May 2, 1857 at the age of 44.

His wet-collodion process was used on every continent and survived with the work of itinerant tintype photographers well into the early twentieth century.

In rural California in 1865, Hart had to be prepared to produce his photographic emulsions from rather basic materials, some of which were explosive and some poisonous, although none were both--unless one considers the fumes of ether as a poison. Thus, it is not surprising that photographers of his era also became chemists to a degree determined by their distance from a metropolitan center of photographic supplies.

There was some published support available in that the instructions for the preparation and use of the materials of the wet-plate or collodion process could be found in books, articles, and occasionally from the writings of the photographers themselves. Most of the data in this essay (including the woodcuts) were obtained from a single small book called A Popular Treatise on Photography (1867). The perhaps excessive details are included to give the reader some idea of the great difficulties and actual hazards faced by Alfred A. Hart in practicing wet-plate photography. (An amazing complexity by comparison with today's point-and shoot picture taking.)


Assuming that factory prepared photographic collodion was not available, the following raw materials would be needed to prepare it. For the iodized Collodion:

1. Ordinary cotton free of impurities

2. Saltpeter, (potassium nitrate) finely granulated

3. Sulfuric acid

4. Small ingots of metallic cadmium

5. Crystalline iodine

6. Liquid bromine (vapor highly injurious and corrosive, very volatile- therefore kept under water)

7. Clear filtered alcohol

8. Thoroughly washed and distilled ether

Items 1, 2, and 3 were used to prepare gun cotton which was invented by a German chemist in 1846. Photographic "iodized," or "sensitized" collodion was prepared shortly before use by mixing two very stable solutions that could be kept for long periods, i.e., plain thick collodion and the iodizing solution.

Plain collodion was prepared by mixing guncotton with a solution of 22 percent alcohol and 78 percent ether, strongly agitating, and allowing the resulting mixture to settle for several days. The clear solution was then poured off into smaller bottles for use (solution No. 1) as needed for mixing with the iodizing solution within 24 hours of use. Iodized collodion had to be kept in the dark in well-stoppered bottles. If kept more than 48 hours, there was a tendency for its sensitivity to be reduced.

The viscosity or "thickness" of collodion could be increased by adding more guncotton, or reduced by adding more alcohol and ether. The iodizer (solution No. 2) was prepared by dissolving cadmium iodide and cadmium bromide in alcohol. This solution was then carefully filtered into smaller bottles. Solutions No. 1 and No. 2 could be preserved for any length of time if kept separately in tightly closed glass bottles.

Four ounces of sensitized or iodized collodion was prepared by mixing, by volume:

Thick plain Collodion(No. 1) 26%

Iodizer solution (No. 2) 10%

Alcohol 19%

Ether 45%

Immediately after being well shaken to mix the ingredients, the sensitized collodion was ready for use, but was improved by a delay of a few hours.

The most desirable glass plates were true "plate glass"; that is, the surfaces were ground flat and parallel, with the edges smoothed after cutting to size with a diamond point glass cutter.

Kibbey Figure 52

(Fig. 52) Equipment for polishing glass plates. Tripoli bottle, plate clamp, and plate holder. (Van Monckhoven, 1867)

For smaller sizes like one half plate (6 1/2-inches by 4-1/4 inches), ordinary window glass could be used. Whatever glasses were employed, they had to be cleaned and polished before coating with collodion. The plates were first immersed for one hour in dilute nitric acid or a 50 percent solution of carbonate of potash. After this they were thoroughly washed and allowed to dry in a rack in a dust-free atmosphere.

The plates were then polished on the side to be coated with a mixture of tripoli powder and alcohol spread with cotton, and finished when dry with an exceedingly dry chamois. It was recommended that this cleaning and polishing should be done within 12 hours of use.

The polished plates were immediately placed in an absolutely dust-free box having internal grooves (to separate the plates) for transport to the point of coating.


The iodized collodion was flowed onto the plate and the excess caught in a small bottle, and the plate was then tipped back and forth to ensure an even coating over one side of the entire plate.

Up to this point, the operations described could be carried out in daylight. The following steps which included sensitizing the plate, loading it in a holder, unloading the holder after exposure, developing, washing and fixing had to be done in subdued yellow or red light. In Hart's case this occurred either in a dark tent or the darkened area of his photo-wagon.

Depending on the temperature, within 20 to 60 seconds after coating the plate with collodion, the plate was

Kibbey Figure 53

(Fig. 53) The dark chamber, including the yellow filtered window at right. The intensity of the light could :be varied by shortening the chain on the shutter at its bottom. (Van Monckhoven, 1867)

dipped in a narrow glass tank filled with enough 9 percent silver nitrate solution to cover the plate. A hook made of silver plated wire, gutta percha, or whalebone was used to support the plate as it entered and was removed from the tank. The plate was gently moved up and down to minimize streaks and then smoothly withdrawn from the bath.

In addition to glass, silver nitrate solution tanks were available made from gutta percha, porcelain, and an American product called Mathiot's Photographic Ware.

Kibbey Figure 54

(Fig. 54) Coating the plate with collodion. (Van Monckhoven, 1867)

The film of collodion turned white due to the conversion of iodide of cadmium to iodide of silver, which is sensitive to light. The wet, sensitized plate was then loaded into a plate holder ready for exposure in the camera.

The next step involved the use of the camera, its lenses and associated support items. A full description of Hart's camera equipment would be logical at this point,

Kibbey Figure 55

(Fig. 55) Receiving the used collodion into a bottle for later addition of ether and alcohol evaporated during the coating process. (Van Monckhoven, 1867)

but in deference to the fact he had to follow through with the development of the plate within five minutes of coating, the description of his camera will be deferred until later.


The developing process reduced the exposed portions of silver iodide to opaque metallic silver. This was followed by washing off the chemicals used, and fixing with hyposulfite of soda to remove any unexposed silver compounds, followed by another washing. Until the negative had been immersed in the fixing or hyposulfite bath, it had to be kept out of white light (dim red or yellow light was permissible). In Europe the developer often used in the early 1860s employed pyrogallic acid. This material was rather unstable and tended to decompose in a day or two.

Kibbey Figure 56

(Fig. 56) Glass silver nitrate solution tank used to sensitize the coated plate. A surviving example which would have been the right size for Hart's plates has inside dimensions of 9" deep, 7" wide and 3/4" thick.

The silver plated devices to lift the plate out of the bath are shown at the left, but even using those did not protect the photographer's fingers from the blackening effect of the silver nitrate (Von Monckhoven).

Even the water used was best distilled or filtered rainwater (being careful to avoid that gathered during a storm, because lightning converted some of the atmospheric nitrogen into ammonia and nitric acid). Hart, on the other hand, probably used the iron development system (based on sulfate of iron) because it greatly reduced the length of exposure and was popular in the United States. The developer was prepared by mixing:

Saturated solution of iron sulfate 15%

Water 78%

Glacial acetic acid 5%

Alcohol 2%

About four ounces of this solution were placed in a small glass and from it poured over the negative to be developed, starting at one corner. The excess developer was caught in the same four-ounce glass, while the negative was tilted back and forth. This process was repeated until all of the details of the image appeared, although very faintly. Then the iron solution was poured off and a weak solution of silver nitrate poured over the surface of the negative and spread again. (Fig. 57) Developing the negative. (Van Monckhoven)

After the silver nitrate had spread over the whole surface the original developer was again poured over it and spread by tilting. The contrast or intensity of the image was increased from the original faint image by each application of the silver nitrate solution. This required frequent inspection in the dim light of the dark tent to avoid over development.

For thin or underexposed negatives it was sometimes necessary to repeat the addition of the silver nitrate two or three times.

As soon as the negative reached the desired level of intensity in the shadow areas, the development was halted by washing with water. At ordinary temperatures the picture was sufficiently developed in two minutes, while at the higher temperatures Hart encountered, 30 seconds might suffice. To quote Van Monckhoven: " Experience alone can give the knowledge necessary to determine exactly the when and how in this delicate operation." Care was also necessary in washing off the developer to avoid detachment of the fragile collodion film from the glass plate. After washing, the unexposed portions of the negative still retained the yellow-white appearance of the original silver iodide. This was removed and the negative "fixed" by immersing it in a 17 percent solution of hyposulfite of soda until the last traces of the pale yellow silver iodide had disappeared.

A few seconds after the negative was placed in the hyposulfite bath, the tray containing it could be taken into daylight allowing the photographer to confirm when the silver iodide had been completely removed, and ordinary daylight from that time had no action on the picture. The time required in the hyposulfite varied from 30 seconds for a fresh solution to a few minutes for one that had been much used. When the fixing was complete, the negative was carefully washed, first with a fine jet of water and then by immersion for at least 5 minutes in a clean water bath.

To a modern photographer, washing the negative after fixing is generally a signal to relax. In Hart's day, however, it could be a time of great anxiety. The problem was that during washing the collodion film might become partially or wholly detached from the supporting glass. The detachment usually started at the edges of the negative; so the fine water jet from the washing bottle was always directed at the center of the plate allowing the water to run outward over the edges.

Poor adhesion could also result from the use of impure guncotton, an insufficiency of ether in the collodion, improperly cleaning the glass prior to coating, or wash water that was too warm. A variation of the problem sometimes arose when the negative was placed on one edge to drain, and the collodion film could wrinkle and sag of its own weight.

This latter situation could sometimes be corrected after the excess water had drained away by very carefully drawing the emulsion to its proper position with a finger. Detachment of parts of the emulsion, while in the washing bath, was occasionally corrected by the gentle removal of the plate and returning the detached portions of the film "by a very fine and light jet of water applied to the required places." After final washing the plate was placed on its edge on an absorbent surface and leaned against a wall to dry, collodion side out if in a hurry and collodion side to the wall if dust were a problem. In summer, in the Sierra or on the Nevada desert, Hart's negative would dry in less than ten minutes and he could then be ready to move his equipment to another location.

To summarize, under ideal conditions, using the wet collodion process and iron development, Hart could take about one exposure every five minutes, with an assistant handling the final washing and drying.

If required to dry the finished negative and pack it to move to a new location, Hart needed at least 15 minutes between photographs (longer under humid or cold conditions).

From his stereographs, it appears th at H ar t w or ke d ou t so me method of taking at least two and probably three or four exposures within minutes of each other. Several possibilities have been suggested for slowing the evaporation of solvents from the exposed plate, so that time could be available to expose several negatives in succession, or even allow transport to a more convenient location before development.

Kibbey Figure 57

However, if Hart did occasionally make multiple exposures before developing, he would probably have preferred a dry collodion process in which the collodion was sealed in by a preservative to be later penetrated by a developer in the proper solvent.

All of these dry processes had certain disadvantages in comparison with the regular wet collodion process, but they did eliminate the need for carrying a dark tent and chemicals to the camera site. The preparation of the plates for processes A. and B. (in the table above) were long and critical procedures, but seemed to yield the best detail in the finished negative. The rapid acceptance and enthusiasm with which commercial dry plates (based on sensitized gelatin) were received in 1881, would tend to confirm that the earlier dry collodion was only really useful in special situations.

In both wet-plate and dry-collodion processes, except the collodion-albumin, the finished negative was coated with clear varnish on the collodion surface. This was necessary because this image surface was fragile and would quickly wear or abrade without protection. At the same time, printing paper coated with albumin sometimes became sticky in damp weather and could pull off parts of an unprotected negative. In making hundreds of prints from a single negative, Hart would have had to revarnish the collodion surface at frequent intervals.

To the reader, it should now be obvious that Hart and others using the wet collodion process could vary virtually every characteristic of their photographic emulsions by design or error. They could change the concentration and composition of the sensitizing and developing solutions in addition to the timing of each operation. Thus, in every beautiful negative where the photographer's artistic ability was obvious, lay a hidden and almost superhuman attention to the details of the photo-chemical process.


Without written records, the exact details of Hart's photographic equipment are unavailable. It is clear, however, that he employed stereo cameras common in the 1860s, as evidenced by the inspection of contact prints made from his negatives, the two of his published stereographs that actually show a camera (Appendix A, Nos. 179 and 188 [a]), and the shadow of his camera appearing in a few of his published stereographs.

One hundred and thirty years later, working, wet-plate stereo cameras are very hard to locate, but a New York dealer, Allen Weiner, kindly provided one made by Otto Loehr of New York which is shown in the photograph on p. 90. (Fig. 58).

As Hart's would probably have been, this camera is entirely American made, with the high quality lenses manufactured by John Dean of New York. The outfit is provided with a fitted hardwood case containing the camera, a spare lens board for single lens operation, a box of metal diaphragm or "f/stops," the two lenses, a black focussing cloth, two removable "septums" or flexible center dividers which kept the images apart in taking stereos, and two 5-by-8 inch negative holders.

Kibbey Figure 58

(Fig. 58) Wet plate stereo camera of the 1860s. The lens caps in the foreground were used to time the exposure, and the slits to accommodate the removable diaphragm stops are just above the focus-knobs. (MBK photo)

Kibbey Figure 59

(Fig. 59) Print from a full 5" x 8" stereo negative taken with the camera shown in (Fig. 58). The print images have not been transposed. Points AA in the distance are closer together than points BB in the foreground, and the head seems shifted to the left in the left image. For stereo viewing the reverse must exist and is accomplished by cutting the print and interchanging the left and right images. (60% of original size.)

Kibbey Figure 61

RIGHT: (Fig. 61) Clockwise from the top: Lenses and stereo lens-board for the camera in (Fig. 58), septum which separates the space behind the lenses and is accordion pleated so the back of the camera can move back and forth in focussing, two pairs of (Waterhouse) diaphragm stops (f/18 and f/11), and on the left the lens-board used for single lens panoramic views taken with the septum removed.

Kibbey Figure 60

(Fig. 60) Full print with single lens at center of lens-board. The edge of the lens's working circle is clearly shown. Taken with the wet-plate panoramic camera pictured inside the front flyleaf. (MBK photo)

Kibbey Figure 62

LEFT: (Fig. 62) Hart No. 44 of locomotive HUNTINGTON on Cape Horn with his regular lens. Looking SW from the cliff above the tracks.

Kibbey Figure 63

RIGHT: (Fig. 63) Hart No. 44 taken from a few feet to the left with a camera having lenses with double the focal length of the those used for (Fig. 62). The distant bridge over the American River is twice as long in this view.

Kibbey Figure 64

BOTTOM LEFT: (Fig. 64) Portion of Hart No. 188 (a) showing his large camera and carrying strap.

Kibbey Figure 65

BOTTOM RIGHT: (Fig. 65) Portion of Hart No. 179 Old Man Mountain. Looking south from near Meadow Lake. Hart is thought to be the man resting his hand on the same large camera at the left, while his dog looks at the camera or the man in front of it

In the field, Hart could move his camera short distances while still attached to its tripod (the large camera strap shown in Appendix A, Nos. 179 and 188[a] may have facilitated this). Assuming his equipment was closely similar to the example previously described, this outfit would weigh:

Camera 5.5 pounds

2 lenses on mounting board 3.5

Dark cloth 1.0

2 loaded plate holders 3.0

Tripod and attachment hardware 5.0

Total 18.0 pounds

This, of course, covered only his minimum outfit. As mentioned later, Hart also used a another, larger, and heavier camera. It required a stronger tripod and was provided with a leather or fabric shoulder strap, perhaps for carrying the camera separately or with the tripod as described above.

Hart would have used photographic lenses constructed with from two to four elements. Those with only two elements gave the optical designer limited ability to correct aberrations in the optical images formed, but they still worked reasonably well. Four element lenses were better, but more expensive to manufacture. Fortunately the wet plate emulsions were highly sensitive only to blues and greens thus reducing the problem of chromatic aberration (the inability to bring light of all wavelengths to focus at the same point). In addition, most other lens problems were reduced by using the small f/stops needed for the greater depth-of-focus in stereo photography. The largest apertures were around f/8 for average quality lenses and up to f/4.5 for the more expensive ones. Focal lengths tended toward wide angle for the negative being used.

From evidence found in Hart's published stereos, he used at least two different length lenses in taking his photographs. His usual lens covered a circle of 4-7/8 inches. By comparing twentieth century images of the same scenes with Hart's views, this lens appeared to be slightly wide angle; about a 6-inch focal length having a coverage similar to a 30 millimeter lens on a modern 35 mm format. His longer lenses had focal lengths about 2.1 times as long, comparing to a 65 mm lens on a 35 mm format.

In estimating comparative camera focal lengths from contact prints, one must examine variations of negatives taken of the same scenes, to determine if lenses of different focal lengths were used while the camera location, and objects photographed remained the same. If the negatives were available, the larger image circles resulting from the long lenses would make the determination easy, but in Hart's case it must be done by finding specific instances where he took the same scene twice from about the same place and published both results.

A comparison of the size of an object in the foreground of two views of the same location cannot be used alone,

although from the same location a longer lens would produce a larger image of this object on the negative. The two photographic images must be carefully compared to insure the foreground is similar and that the distant objects appear larger with the longer lens. In general, long lenses compress the background. That is, objects on the horizon (or over 500 feet away) appear larger and therefore closer to the foreground (see Fig. 63)

By comparing the separation of two summits on the distant mountains in Hart No. 109 and 109(a), it can be seen that his long lenses were about 2.1 times the focal length of the shorter ones. If the short ones were of 5 to 6 inch focal length, (estimated from the image circle and angle-of-coverage mentioned earlier), then Hart's larger camera, with the longer bellows extension, would have had lenses with about 10-1/2 to 12 inch focal length.

Since around 1895 when the Carl Zeiss Company

began producing lenses which were true telephoto lenses (with a negative lens at the back), an effectively long lens can be used on a small camera, with no appreciable change in the lens-to-film distance. Such lenses were not available in Hart's day and to use a long lens giving a bigger image, he had to employ a camera with a lens-to-film distance at least two and a half times that of his small camera. Hart could have accomplished this in several ways, but he simply obtained a larger camera which accommodated the longer lenses. The two scenes which include a large camera at the left, confirm that he kept his long lenses on a different, and larger, camera. In addition, if he had just changed to long lenses on his regular camera, why would he then have picked up the camera and moved it to the left for the long lens exposure? (See Appendix A, Hart Nos. 44, 44 [a], 109, and 109 [a].)

If, as the evidence seems to show, Hart used two different cameras in his railroad series, he always placed the long focus camera on the left, and often a bit lower. The two instances where a large camera is included in a view (No.188 [a] "Castle Peak" and No.179 "Old Man Mountain"), we see this

Kibbey Figure 66

(Fig. 66) 1860s Tripod. camera lower and to the left.

In No. 109 Summit Valley (long lens) the camera is to the left of its position in No. 109(a), but the elevation seems about the same. In No. 44 "American River" (long lens), by noting the position of the smoke stack against the distant brush, it can be seen that the camera was lower and to the left of its position when taking No. 44(a), an obvious wide angle shot.No. 258 "Castle Peak from the Railroad" and No. 258(a) illustrate similar positions. Possibly because of its size, Hart did not take his long focus camera to Promontory, while Russell did, with superior results. Compare Hart's No. 357 from UP locomotive 119 (Fig. 26) and A. J. Russell's view from the roof of the cab of the JUPITER. (Fig. 27)


Hart's substitute for a modern shutter was to time the exposure with his black focussing cloth draped over the lenses and removed for the correct time, or the lens caps could be used for the same purpose. From the actual photographs, without knowing the aperture size, it is generally difficult to estimate the exposure times employed by Hart.

The existence of ghost images, occasional movement of people and horses in the outdoor scenes and fuzzy views of flowing water would suggest something longer than one second, but how much longer is difficult to say. Clear images of little children, as at the left in Fig. 18: End of Track on Humboldt Plain would probably mean an upper limit of 2 or 3 seconds, and possibly less.

A remarkable Hart stereo view published without a printed title or number and taken in the Senate Chamber of the California State Capitol, includes a clock at the back of the room (Fig. 67). The minute hand of this clock has moved over about three minutes during the exposure. The time indicated is during the noon hour and light is coming from the high and seemingly large windows of the chamber. Assuming the senators needed enough light to read the fine print on the bills being considered (a brightness scale reading of six on a modern exposure meter) and that Hart selected a stop such as f/32 to get the depth of field needed in interior stereos, then the exposure mentioned would suggest a film speed of ASA 9.

This same film speed on the bright Nevada desert (brightness scale 13) would require f/32 at 2 seconds. Likewise, inside the tunnel shown in No. 197: Summit Tunnel before Completion, Hart could have used a fairly short exposure -- in early September around 5:30 p.m.-- when the setting sun shown directly into the tunnel (Fig. 6).

These estimates are roughly corroborated by a statement in Van Monckhoven's book warning of the danger of overexposure due to the great sensitivity imparted to wet collodion negatives developed by the iron process.

Kibbey Figure 67

(Fig. 67) Alfred Hart: 1868 Senate Chamber of State Capitol. As mentioned in footnote No. 95, his suggested exposure would also indicate a film speed of ASA 9.


The wholesale production of stereo cards was an industry in itself. Starting in 1851 with views of the International Exposition in the Crystal Palace in London, thousands of stereographs were produced each year. In 1854, stereograph manufacturing was begun in the United States by William and Frederick Langenheim. The invention of the inexpensive Holmes-Bates viewer in 1860 and the widespread introduction of the inexpensive paper stereograph mount, greatly increased demand. During the period from 1861 to 1873 there were hundreds of stereograph producers who measured their annual volume in the thousands, although the total number produced is not available. As an example, Hart, who was a relatively small producer, sold over 7,000 stereographs to one customer, the Central Pacific Railroad, in 1869.

In his early years with the CPRR Alfred Hart mainly left the finishing task to established stereo-publishing firms such as Whitney & Paradise or Lawrence & Houseworth. Other photographers often handled stereograph production in their own studios. The process could be divided into four tasks:

1. Making and masking prints from the negatives

2. Obtaining and/or imprinting the mounting cards

3. Trimming the prints and mounting them on the cards

4. Adding the titles, and usually, a series number.


In Hart's time, the prints were made on a thin, high quality paper, (which was often called "albumin paper"), first treated on one side with a coating of albumin (egg whites containing sodium chloride, whipped to a froth, and filtered) which gave much finer detail and a glossy surface. The glossy effect could be varied by mixing from 10 to 40 percent water with the albumin; more water yielding a duller surface.

Directly sensitized, or "salt paper" (without albumin) was not used for stereos, but recommended for portraits and some landscapes because it gave a softer image and also for very large prints because it was easier to make.

Kibbey Figure 68

(Fig. 68) 1860s Printing Frame (Van Monckhoven).

Kibbey Figure 69

(Fig. 69) Rack for holding print frames in sunlight.

Kibbey Figure 70

(Fig. 70) Examining the action of light on the printing paper. Only half the back was opened so the print and negative remained in register when the back was closed for further exposure (Van Monckhoven, 1867).

Kibbey Figure 71

LEFT: (Fig. 71) William Keith's woodcut based on Hart's No. 171 Miller's Bluffs- Old Man Mountain in dist. for publication in the San Francisco California Weekly Mercury. Keith followed Hart's view quite closely, but turned the train around and added several cars.

Judge Crocker, over Huntington's objections paid to have this series of woodcuts made, without credit to Hart, and had them published serially starting in October of 1867. Huntington was not concerned about the lack of credit to Hart, just the cost.

RIGHT: (Fig. 72) William Keith's woodcut based on Hart's No. 129 Donner Lake, with Crested Peak and Mt. Lincoln in distance for publication in the San Francisco California Weekly Mercury. Keith followed Hart's outline of the mountains closely, but altered the early morning tranquility of Hart's view by adding the overloaded rowboat in the foreground and, on the mountain, the coal-burning locomotive (smoke from wood fuel, which the CPRR used, tends to be white). The Summit Tunnel wasn't completed until 48 days after this publication date; so Keith's scene is not "from life."

Hart made his stereo prints on paper about 4/1000 of an inch thick, coated for a few minutes on one side with a dilute solution of sodium chloride in albumin, and then dried. Factory produced albumin paper could also be purchased commercially. Whether purchased or coated by the photographer, the albumin paper contained only salt in albumin and was not sensitive to light. It was also very fragile and had to be handled carefully by the edges. If the surface were touched by the fingers, stains in the finished print were likely to occur. The dry sheets of albumin/salt coated paper could be kept for long periods in tight, dry, tin or zinc boxes. Moisture, particularly when combined with high summer heat, resulted in the rapid deterioration of the albumin.


Working in deep yellow or yellow light, the printing paper was sensitized by floating it for three or four minutes on a bath of 80% water and 20% silver nitrate with about 2.5% Kaolin added to maintain clarity. Without this latter substance, a deep yellow tint would rapidly develop which would create an unpleasant color in the final print. Up to 150 sheets of paper 5 by 8 inches could be sensitized in 24 ounces of this solution. The paper was again dried by hanging as described in the previous footnote. The dry sensitized sheets had to be stored in darkness and used within 48 hours unless specially preserved.

In Hart's day, printing on the relatively insensitive silver chloride paper required a prolonged exposure to direct sunlight. The long exposures were necessary because no subsequent chemical development of the latent image was employed, and the action of light alone broke the silver/chlorine bonds and deposited the metallic silver of the image. The exposures, often measured in hours, required a substantial investment in print frames and copy negatives (mentioned in footnote 56) for quantity production, but gave the photographer ample time to monitor the progress of exposure and to fix and tone prints while others were still being exposed.

To make the exposure, the necessary materials were arranged in the inverted printing frame in the following order (starting with the plate glass in the print frame which would be turned to the sun):

1. The heavy glass of the print frame.

2. An opaque mask of black paper or other thin material

to obscure unwanted portions of the negative.

3. The negative with the plain glass side in contact with

the mask and the collodion side to the rear.

4. The sensitized printing paper with sensitive side toward

the collodion side of the negative.

5. The wood, hinged back of the print frame with the felt

side on the back of the printing paper.

This operation was conducted in yellow light to protect the sensitive paper. The print frame was then tightly closed, taken outdoors and turned so as to expose the plate glass side to direct sunlight. Contact printing frames sold today are almost identical with those used in Hart's day, including the hinged back needed to hold one end of the paper tight against the negative while the other end was opened in subdued light to allow inspection of the emerging image (Fig. 68). The darker portions of the print (under the lighter areas of the negative) passed successively through the following colors as exposure progressed:

1. Very pale blue 4. Deep purple

2. Pale blue 5. Black

3. Clear Bluish Purple 6. Metallic grayish black

7. Olive, or greenish bronze

The progress of the exposure could be examined by opening one half of the print frame as shown in the illustration taken from Van Monckhoven's book (Fig 70). It was important that the print should appear darker than seemed necessary because of the fading which occurred in subsequent treatment. Experience and a well-honed judgement were needed to determine the exact moment the exposure ended, particularly as the print would undergo some fading in both the fixing and toning baths. Even when exposed until a black image appeared, the final print would have a brown color after fixing.

After being exposed, the prints were thoroughly washed in plain water to remove the free silver nitrate, gold toned, washed, fixed in hyposulfite of soda, washed again, and dried. Many of Hart's surviving prints are overly dark, indicating insufficient fixing in the hypo or more likely, overexposure in printing. This could have occurred because he meant to gold tone the prints (which made them fade somewhat) but then skipped that step. The fault was not in Hart's negatives because when Watkins later printed the same negatives, dark prints did not result.


The stereo negative as exposed in the camera measured 5 by 8 inches and contained two images each about 4-3/4 by 3-3/4 inches. The final contact prints Hart attached to his published stereographs were about 3 inches square, with square corners (some used a dome-topped shape, possibly to eliminate dark upper corners)

Although he could have printed the entire negative, and then carefully trimmed each image to the required size, the difficulties involved for a large production run are obvious. It was much more sensible to make a mask of a piece of black paper 5 by 8 inches and cut out two holes 3 inches square, place it in front of the negative, and thus make prints with the images consistently showing the desired portions of the negative and always of the same size.

Control over four factors important in stereo card production resulted from printing a portion of each image on the negative to set sizes controlled by two rectangular openings in a mask covering the whole negative. First the separation of the two openings in the mask determined the optical spacing and thus the type of viewer required to bring the finished images into visual coincidence allowing the eyes to effectively see "depth". By the time Hart was making stereographs, manufacturers of stereoscopes or viewers in the United States had already standardized on prismatic lenses that allowed a person with normal vision to merge views with an optical spacing ranging from 2-1/2 to 3-3/8 inches.

With these viewers, optical spacings of 1/8 inch either side of 3 inches were the easiest to view. It appears Hart's negatives (and thus his taking lenses) had an optical spacing of about 3-1/4" which he reduced to 3 inches, or a bit less, by adjusting the printing masks. An exception to this optical spacing occurs in most of the stereographs which he published with the back imprint "for the CENTRAL PACIFIC RAILROAD COMPANY." These had reduced optical spacing, possibly to include additional coverage at the edges of the images, or to permit the use of simpler viewing devices. In a random selection of 12 such stereo cards the optical spacing varied from 2-1/2 to 3 1/8 inches and averaged 2-3/4 inches.

In addition to the standard viewers, many other sizes were produced for a wide variety of optical separations. One of the more unusual, being a tiny German "Taschen Stereoskop" model for 1 by 1 inch images with an optical separation of 1 3/4 inches and lenses adjusted to increase the separation to that of normal human eyes

Kibbey Figure 73

(Fig. 73) Hart No. 199 masked to give optical spacing of only 2". Hart may have made it for free-viewing or a special viewer.

The second factor controlled in masking was that any tilting of the camera at the time of exposure (not a common problem) could be corrected. Third, the size of the prints could be adjusted for regular, cabinet, or even small European formats by means of appropriately sized openings. Fourth, the openings in the mask could be positioned to print the parts of the negative yielding the most interesting information.

In this last consideration, Hart seemed to feel that the tops of distant mountains should always be included to establish a skyline, or at the least the upper part of the negative was as important as the foreground. An example of this can be seen in Appendix A: Hart No.123: Lakeview Bluff, taken from the Dutch Flat and Donner Lake wagon road before the tunnels were finished.

Hart's published view shows all of the rock above tunnel 8 and most of the tree at the left, but nothing of the road. From the un-cropped print at the Society of California Pioneers one can see that the deeply rutted wagon road at the bottom was included in Hart's original negative. The road is historically significant and illustrates man's effort to conquer the difficulties of that area. Watkins seemed to agree because when he published this view from Hart's identical negative, his masking showed a portion of the road and cut off at the exact top of the rock.


Exposed prints were stored in a tightly closed box with calcium chloride until there were enough on hand for efficient processing. In yellow light ten to fifteen prints at a time were immersed in a water bath for 10 minutes to remove the silver nitrate not affected by the exposure. Since it was very easy to stain the albumin surface, handling was done with wood or bone forceps.

The prints were then transferred separately to the toning bath, a solution of gold chloride, bicarbonate of soda, and a pinch of common salt. The prints first turned red and then gradually shifted in color to black and then bluish black.. Toning could be stopped at any point by placing the print in plain water. After washing, the prints were then immersed in the fixing bath of hyposulfite of soda for 10 to 15 minutes.

They were next rinsed in a water bath and then soaked for two hours in one water bath followed by three hours in another. If running water were available the five hours in the last two baths could be reduced to 10 or 15 minutes.

After being dried, the prints were ready for trimming and mounting. Because the printing mask was separated from the collodion image by the thickness of the negative glass (usually 1/16" inch), and the sun moved during the long exposure, a slightly fuzzy edge resulted. Hart trimmed off the blurred edges of his prints to a square shape using shears or a paper cutter. Some other photographers prepared dome topped prints or other shapes using steel or glass guides and a sharp knife. Others also produced "deluxe" albumin prints and would finish the mounted print by covering it with a thin layer of very clear varnish, and after drying, roll it through a polished steel roller to give it a high gloss. However, examination of Hart's stereographs under a low-power microscope suggest that he did not varnish his prints.

By the 1860s American stereographs were fairly well standardized at 6-3/4 to 7 inches long and 3-1/4 to 3-5/8 inches wide. Width varied upward for some makers (but not Hart) to a 4-1/4 inch "cabinet card" size. Hart was quite consistent in the size of his individual finished images (the two prints glued on a card mount), and in checking a random selection of a dozen prints, sizes varied only slightly from 2-15/16" to 3-1/8" high and 3" to 3-1/16" wide. While an occasional Hart card mount is larger, the great majority were 6-3/4 x 3-1/4 inches. Normal stereoscopes or viewers, described on pages 105-108 had mounting frames for the 7 inch length, limiting publishers to that length or a little less. As occurred frequently with stereographs published in the 1860s, the fronts of Hart card mounts bore printed "series" notations on the left end of the card like, "Central Pacific Railroad" or "Hydraulic Mining," and the state or region in which the view was taken appeared on the right end. The backs of Hart's card mounts were imprinted with his logotype including his name and other information. Copies of all of his back imprints known to this writer(and Hart had far more than any other publisher}, are in Appendix A (pp. 140 146).


In mounting the images on the card, it was essential that the print taken with the left lens be placed on the left (and the right one on the right). If this rule were not followed, the true depth effect was lost and frequently objects further from the camera actually appeared closer. Because of details of the image-forming process occurring in stereo cameras, it was necessary to transpose or interchange the left and right print images made from the full stereo negative.

This was accomplished by the simple process of making separate prints or making a print of the full negative and cutting it into two. The resulting positive images were then glued to a mount card in the opposite positions they occupied in the print frame.

This process resulted in the exchanging of the left and right images and was called "transposing." If the photographic printer fails to mark the left or right images of a stereo pair, or if they somehow get mixed up before being attached to the card, identification of the left and right image must be done by looking closely at the views themselves. Unfortunately there is nothing like "perfect pitch" in left/right stereo images. If only a single image is available there is no way to tell if its a left or a right, but if both images are available and in them close objects are visible against a more distant background, identification is easy. With the two images attached, one measures the optical spacing of foreground and background objects. If the foreground optical spacing is smaller than the background spacing, the prints are correctly oriented and the left print belongs on the left. When the foreground spacing is larger (as in Fig. 59, p.91), the left image is on the right and transposing is required for stereo viewing.

For pairs of loose or unmounted prints, the foreground is shifted to the left in the right image and vice versa in the left one. Occasionally a tiny "x" was marked on the negative at the outside lower corners, these marks appeared next to each other at the bottom center on a proof print after transposition. They were normally trimmed off and were not visible on the finished stereograph.

Hart, and many of his contemporaries, provided another identifying feature which helped determine the left and right images of a stereo set. Hart almost always printed a bit more of the left side of the scene in the left image and more of the right side in the right one. This was done in the masking process and probably to adjust optical spacing.


Titles identifying the scenes on the Hart cards were printed in tiny 6 point type on thin yellow paper. If the title ran more than four or five words, the remainder was set in even smaller 4-point (about 1-1/2 millimeter high) type. These narrow title strips (varying from 1/8 to 3/16 inches wide) were then cut from a larger sheet and glued below the image on the right. For the lucky person assigned this job it would have been nice to have had one or more sheets for each one of the 364 views. Then by picking the correct sheet it would be only necessary to snip off the top label and glue it down.

Unfortunately that would have meant that the printer would have had to set a page of that eye-killing type for every view--364 settings. Instead the strip labels were printed in sequence, and about 200 could fit on an ordinary piece of typing paper. Thus, with only two setups, any number of full sets could be printed by just running more copies. The proof of Hart's use of this method can be found on his stereographs in the Library of Congress collection where a bit of the preceding or following numbered title has been left attached.

If one visualizes the finisher working by lamplight on a rush order, surrounded by partly cut-up, lace-like sheets of labels, it's certainly understandable that occasionally the wrong label was used. With a magnifying glass, evidence of this problem can be found on some of the view mounts in Appendix A.

In contrast, Watkins printed the identifying labels in about the same size type, directly on the card. He may have had the card printer do it in advance, but it would have made more sense to use a tiny hand press in his own shop. Occasionally a Watkins card will have the title too deeply impressed into the card stock or not perfectly aligned with the bottom edge. Both suggest the small hand press. Possibly because of this method, incorrect labels on Watkins views are very rare. Hart also employed direct printing on some of his late "For the Central Pacific Railroad "cards.

As an aside, because of the care and dexterity of the printers of that era who set all that tiny type by hand, one almost never sees a misspelled word in a card label. When pressed for space, they got a little imaginative with abbreviations, but seldom with spelling. In one instance (No. 311) Hart's printer, who may have just been setting type for menus, spelled "desert" with two "s's."


When first looking at a stereo card held at normal reading distance, the eyes consider it like anything else and converge or turn slightly inward. This causes both eyes to look at the same close location and incidentally refocuses the lenses for close use. However in viewing stereo prints, the three-dimensional or depth effect occurs when the observer is able to merge the two images into one while maintaining sharp focus, either by means of an optical device called a stereoscope or unaided as in the following description of free viewing by directly viewing the stereograph without the intervention of the prismatic lenses of a stereoscope.

The turning muscles in the eyes relax (but not those that control focus) as they do when viewing a distant object, and the eyes see each image as a separate scene just as they would if present at the camera location.

The brain then processes the information received and delivers the sense of a single view, with depth perception, as it would from nature. The process just described is called "free viewing" and because of the necessary independent functions of the directional and focussing muscles, it is easier for nearsighted eyes. Tiny stereo images the size of postage stamps can be free viewed or merged by many people without any optical assistance. Larger images with wider optical spacing are much harder to free-view although through practice or natural ability a few can do it.

For the majority of people in the nineteenth century, stereographs became three-dimensional when viewed through a form of stereoscope, defined in the Oxford English Dictionary as:

"An instrument for obtaining, from two pictures of an object, taken from slightly different points of view, a single image giving the impression of solidity or relief as in ordinary vision of the object itself".

The first stereoscope was invented by Professor Charles Wheatstone (1802 1875) before 1832 and used a concave mirror to magnify and reverse the images.

Kibbey Figure 74

(Fig. 74) Some stereoscopes available in the 1860s. Clockwise from the left: 1. Beck viewer with Brewster type achromatic focussing lenses, for transparent or card-type stereographs. The door at the top had a mirror on its inner surface to reflect light to card views, and the door was closed for glass views. It was stored inverted in the polished wood box upon which it is placed. 2. Another Beck viewer for looking at stereos in books (original instruction sheet in front). 3. Holmes-Bates type of aluminum and wood made by Keystone View Company (Not available in the 1860s). 4. Brewster type viewer made in England. 5. Early all-wood Holmes-Bates type viewer. In the early days of stereographic photography, some books were illustrated with tipped-in stereos, the first being C. Piazzi Smyth: Teneriffe, An Astronomer's Experiment. (London, Lovell Reeve, 1858) which had 20 such views of exceptional quality. (MBK Photo)

Kibbey Figure 75

(Fig. 75) Keystone View Company, Meadville, Pennsylvania 1895-1960: General View of Mounting Department. This was the last and the largest of the American stereographic manufacturers. Their mounts were heavy, curved cardboard. This view seems ca. 1906 1914.

Wheatstone also invented the concertina, the electric Wheatstone bridge, and the revolving mirror used for the measurement of the speed of light. Since 1832 was some seven years before the invention of photography, his first stereoscope was an optical curiosity used with carefully made pairs of drawings, but for a few years after 1839 (until Brewster's invention spread) it was used to view stereo daguerreotypes. Wheatstone also proposed the name "stereoscope" for the device.

In the early 1840's Sir David Brewster, a renowned British optical scientist, invented an improved form of the stereoscope in which a combination of simple lenses and prisms compressed the optical spacing and magnified the images. The magnifying lenses of about 8 inch focus were spaced about 2-1/2 inches apart like human eyes. The prisms, thicker at the outer edges and cemented to, or ground integrally with the lenses, bent the light rays coming from the stereograph so they emerged parallel for a short distance and 2-1/2 inches apart. This permitted ordinary eyes to merge images having an optical spacing of 3-1/4 inches on the stereograph. Brewster's invention was demonstrated at the 1851 International Exposition in London and admired by Queen Victoria.

A rather elaborate stereoscope manufactured by Smith, Beck & Beck of London before 1859 employed achromatic lenses of the Brewster type and would also have been available to view Hart's stereographs. A selection of these viewers is shown in (fig. 75). The term "stereopticon" which means a stereo projection device, like a pair of magic lanterns, is frequently used incorrectly as being synonymous with "stereoscope."

In the United States a viewer using Brewster lenses was perfected in 1860 by Oliver Wendell Holmes (1809 1894) in cooperation with Joseph Bates, a Boston photographer. It was easier to use and cheaper to make than the Brewster stereoscopes and survived almost unchanged well into the twentieth century. All these viewers were required because, with ordinary vision, optical spacing larger than 2 inches could not be merged into a single three-dimensional image, and if held to this restraint only pairs of tiny images each about 2 inches wide could be used. In addition to widening the allowable optical spacing by means of prisms, these viewers also included magnifying lenses to bring out the detail of the relatively small images.

The optical spacing of the mounted images can be measured by getting the horizontal distance from an object in one image, say a flag pole or tree, to the same object in the other image. If the reader decides to check this on a stereo card, it will also be noted that this optical spacing is less for close objects than for those in a distant background.

The reasons for this are further described in the opening paragraphs of Appendix F. In at least one instance, Hart tried an experiment (with No. 199: Wagon Road and east portal of Summit Tunnel) in which he reduced the optical spacing from the usual 3 inches to only 2 inches, possibly to permit freeviewing (Fig. 73).


Photographers, even those working with assistants, rarely appear in their published images. Hart was no exception, and in the entire 364-view series there are really only two or possibly three views in which he may be pictured. In No.179, Old Man Mountain, he may be the man standing beside the large camera at the extreme left. In No. 181, North Fork of the South Yuba, a man (possibly Hart) holding a sketch pad and wearing a hat with a black hat band sits at the right. He appears to be making a portrait of the man with a stiff straw hat sitting facing him, and we know Hart painted portraits in the East, long before his arrival in California. In No.169, Yuba River Valley, and No.170, Cement Ridge, the man riding behind the cab has a hat resembling one seen in earlier views, and it would make sense for Hart to be near the engineer in order to tell him when and where to stop.

The train had actually already stopped, but Hart may not have moved yet. All these observations are mere suppositions and also presume the presence of an assistant to make the exposure. The shadows cast by Hart and his camera appear in several views, always at the bottom and usually at the right: No. 13, View in Bloomer Cut, shows the shadow of large camera with a dark cloth over it.

No. 141, Tangent below Pino, taken near present-day Loomis, California, in the afternoon from the top of a rail car shows Hart's shadow in a long coat and the camera seems the same size as the one in No. 13. No. 224, First Crossing of Truckee River, (Fig. 76) also shows Hart's shadow, and that of a camera with a dark cloth over it.

No. 224, in addition includes a dog (Hart's?) with dark ears and of the same size as the one in No. 179, Old Man Mountain. Another example, No. 225, Bridge over first Crossing (Fig. 39) has the shadow at bottom center and it is clear the camera is small, with light, wishbone-like legs on the tripod. Motion can be seen in Hart's shadow at the right, possibly as he moved the dark cloth or lens caps to make the exposure. In this instance, the tripod legs come all the way to the bottom of the camera, unlike the tripod in Nos. 179 and 188(a) (Figs. 64 & 65) which has short legs and a long, heavy, vertical shaft. In Fig. 27 taken by A. J. Russell at Promontory, Hart is shown on top of a distant locomotive with his smaller camera and the light tripod.

Collectors of vintage photographs will quickly recognize the problem of naming unidentified people. For instance, in many Eastern views every tall man in a top hat is identified as "possibly Abraham Lincoln." In Hart views, modern pencil (or even red ball point pen) notations on the back of the cards identify most tall solemn-looking men as "Strobridge," heavy set ones as "Leland Stanford," and any others not obviously Chinese or North American Indian as "possibly Hart". Lets hope they're all correct.

Kibbey Figure 76

(Fig. 76) Portion of Hart No. 224 First Crossing of the Truckee, with Hart's dog at lower left and his shadow at lower right. (From Society of California Pioneers full-size print ). More detail is shown here at the right and bottom than appears in a normal stereo view.

Kibbey Figure 77

(Fig. 77) Portion of Hart No. 181 showing Artist (Hart in wide-brimmed hat?) sketching a portrait of bearded man.

Kibbey Figure 78

(Fig. 78) West end of Donner Summit Tunnel looking east at about 6:30 p.m. in September 1994. The rails have been removed, but the ties remain. The stone overhead is jet black from 130 years of wood, oil and diesel smoke. (MBK photo)


In addition to the Central Pacific series, Alfred Hart produced other stereo views of Sacramento and its waterfront, interiors of homes and Pullman cars, scenes in San Francisco, views of giant Sequoia Redwoods, of Yosemite, and many other California locations. The Sacramento Archives and Museum Collection Center has an album presented by Hart to Mrs. Theodore D. Judah containing a large (8-1/2 by 6 1/2 inches) Hart image of Mount Diablo. Two or three non-railroad carte-de-visite images with Hart's back imprint are known to this writer.

Of Hart's non-railroad stereographs, few have printed titles and even fewer are numbered, making a systematic classification and dating of these images very difficult. As an indication of their overall appearance, eight of the non-railroad Hart stereographs are included following the CPRR series in Appendix A. An idea of the existing number of these mostly untitled, non-railroad, stereographs on Hart mounts may be gained by noting how many are in some collections where they have been listed separately. One private collection has 41, the Crocker Art Museum has 12 and the California State Railroad Museum at Sacramento has four. Among all these are at least four duplications, and four or more are identical to views published by Houseworth. Hart may have intended to publish other sets because a few Hart titled views exist with numbers above 364, some examples being; one of Yosemite Falls numbered 1008, one of Upper Cisco in winter numbered 491, and one of the levee at Sacramento from the deck of the steamer CAPITOL numbered 838.

It is hoped that further information on these non-railroad views may be published at a later date.

For readers wishing to ask questions or make suggestions the author may be contacted at the following address:

Mead Kibbey 1731 Howe Avenue, #472 Sacramento, CA 95825 PHONE (916) 489-5481--FAX (916) 489-9486 (as of September 2001)



Courtesy Mead B. Kibbey, Author, and a Director of the California State Library Foundation. Reproduced by permission.
This web page which is not for republication was generated from a revised version of the original manuscript file that according to the author, "contains all the text of the Hart book, corrected for the errors found after publication. The section on 'Location of Stereos' has been brought up to date in the K column and some corrections in the Swackhamer and Huntington Columns."

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