Chapter 1

Produced by Olaf Voss, Don Kretz, Juliet Sutherland, Charles Franks and the Distributed Proofreaders Team

SCIENTIFIC AMERICAN SUPPLEMENT NO. 401

NEW YORK, SEPTEMBER 8, 1883

Scientific American Supplement. Vol. XVI, No. 401.

Scientific American established 1845

Scientific American Supplement, $5 a year.

Scientific American and Supplement, $7 a year.

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TABLE OF CONTENTS.

I. CHEMISTRY.--On the Different Modifications of Silver Bromide and Silver Chloride.

Analysis of New Zealand Coal.

On the Determination of Manganese in Steel, Cast Iron, Ferro-manganese, etc.

Manganese and its Uses.

Ozokerite or Earth-wax. By WILLIAM L. LAY. A valuable and instructive paper read before the New York Academy of Sciences.--Showing the nature, sources, and applications of this remarkable product.

On the Constitution of the Natural Fats.

II. ENGINEERING AND MECHANICS.--Improved Spring wheel Traction Engine.--With two engravings.

An Improved Iron Frame Gang Saw Mill.--With one large engraving.

The Heat Regenerative System of Firing Gas Retorts.--Siemens' principle.--As operated at the Glasgow Corporation Works.--With two engravings.

A New Gas Heated Baker's Oven.

III. TECHNOLOGY.--How to Produce Permanent Photographic Pictures on Terra Cotta, Glass, etc.--With recipes and full directions.

How to Make Paper Photo Negatives.--Full directions.

Some of the Uses of Common Alum.

An Improved Cloth Stretching Machine.--With an engraving.

Purification of Woolen Fabrics by Hydrochloric Acid Gas.

Apparatus for Preventing the Loss of Carbonic Acid in Racking Beer.--With an engraving.

IV. ELECTRICITY.--Application of Electricity to the Bleaching of Vetable Textile Materials.--With figure of apparatus.

Table Showing the Relative Dimensions, Lengths, Electrical Resistances, and Weights of Pure Copper Wires.

V. ASTRONOMY.--The Solar Eclipse of 1883.--An interesting abstract from a report of C. S. HASTINGS (Johns Hopkins University), of the American Astronomical Exhibition to the Caroline Islands.

VI. NATURAL PHILOSOPHY.--Recent Experiments Affecting the Received Theory of Music.--An interesting paper descriptive of certain experiments by President Morton, of Stevens Institute.

The Motions of Camphor upon Water.--With an engraving.

VII. ARCHITECTURE.--Suggestions in Village Architecture.-- Semidetached villas.--Bloomfield crescent.--With an engraving.

Specimens of Old Knocking Devices for Doors.--Several figures.

VIII. ARCHÆOLOGY.--A Buried City of the Exodus.--Being an account of the recent excavations and discoveries of Pithom Succoth, in Egypt.--With an engraving.

The Moabite Manuscripts.

IX. AGRICULTURE. HORTICULTURE, ETC.--The Queen Victoria Century Plant.--With an engraving.

Charred Clover.

A New Weathercock.--With one figure.

X. MISCELLANEOUS.--New Monumental Statue and Landing Place in Honor of Christopher Columbus at Barcelona, Spain.--With an engraving.

Scenery on the Utah Line of the Denver and Rio Grande Railway.

Captain Matthew Webb.--Biographical sketch.--With portrait.

The Dwellings of the Poor In Paris.

Shipment of Ostriches from Cape Town, South Africa.--With one page of engravings.

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MONUMENT TO CHRISTOPHER COLUMBUS, AT BARCELONA, SPAIN.

The cultivated and patriotic city of Barcelona is about to erect a magnificent monument in honor of Columbus, the personage most distinguished in the historic annals of all nations and all epochs. The City of Earls does not forget that here the discoverer of America disembarked on the 3d of April, 1493, to present to the Catholic monarchs the evidences of the happy termination of his enterprise. In honoring Columbus they honor and exalt the sons of Catalonia, who also took part in the discovery and civilization of the New World, among whom may be named the Treasurer Santangel, Captain Margarit, Friar Benardo Boyl, first patriarch of the Indies, and the twelve missionaries of Monserrat, who accompanied the illustrious admiral on his second voyage.

In September, 1881, a national competition was opened by the central executive committee for the monument, and by the unanimous voice of the committee the premium plans of the architect, Don Cayetano Buigas Monraba, were adopted. From these plans, which we find in _La Ilustracion Española_, we give an engraving. Richness, grandeur, and expression, worthily combined, are the characteristics of these plans. The landing structure is divided into three parts, a central and two laterals, each of which extends forward, after the manner of a cutwater, in the form of the bow of a vessel of the fifteenth century, bringing to mind the two caravels, the Pinta and Niña; two great lights occupy the advance points on each side; a rich balustrade and four statues of celebrated persons complete the magnificent frontage. A noble monument, surmounted by a statue of the discoverer, is seen on the esplanade.

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The commission appointed in France to consider the phylloxera has not awarded to anybody the prize of three hundred thousand francs that was offered to the discoverer of a trustworthy remedy or preventive for the fatal grape disease. There were not less than 182 competitors for the prize; but none had made a discovery that filled the bill. It is said, however, that a Strasbourg physician has found in naphthaline an absolutely trustworthy remedy. This liquid is poured upon the ground about the root of the vine, and it is said that it kills the parasites without hurting the grape.

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SCENERY ON THE UTAH LINE OF THE DENVER AND RIO GRANDE.

Mr. R.W. Raymond gives the following interesting account of the remarkable scenery on this recently opened route from Denver to Salt Lake:

Having just made the trip from Salt Lake City to this place on the Denver & Rio Grande line, I cannot write you on any other subject at present. There is not in the world a railroad journey of thirty hours so filled with grand and beautiful views. I should perhaps qualify this statement by deducting the hours of darkness; yet this is really a fortunate enhancement of the traveler's enjoyment; it seems providential that there is one part of the way just long enough and uninteresting enough to permit one to go to sleep without the fear of missing anything sublime. Leaving Salt Lake City at noon, we sped through the fertile and populous Jordan Valley, past the fresh and lovely Utah Lake, and up the Valley of Spanish Fork. All the way the superb granite walls and summits of the Wahsatch accompanied us on the east, while westward, across the wide valley, were the blue outlines of the Oquirrh range. One after another of the magnificent cañons of the Wahsatch we passed, their mouths seeming mere gashes in the massive rock, but promising wild and rugged variety to him who enters--a promise which I have abundantly tested in other days. Parley's Cañon, the Big and Little Cottonwood, and most wonderful of all, the cañon of the American Fork, form a series not inferior to those of Boulder, Clear Creek, the Platte, and the Arkansas, in the front range of the Rockies.

Following Spanish Fork eastward so far as it served our purpose, we crossed the divide to the head waters of the South Fork of Price River, a tributary of Green River. It was a regret to me, in choosing this route, that I should miss the familiar and beloved scenery of Weber and Echo cañons--the only part of the Union Pacific road which tempts one to look out of a car window, unless one may be tempted by the boundless monotony of the plains or the chance of a prairie dog. Great was my satisfaction, therefore, to find that this part of the new road, parallel with the Union Pacific, but a hundred miles farther south, traverses the same belt of rocks, and exhibits them in forms not less picturesque. Castle Cañon, on the South Fork of the Price, is the equivalent of Echo Cañon, and is equal or superior in everything except color. The brilliant red of the Echo cliffs is wanting. The towers and walls of Castle Cañon are yellowish-gray. But their forms are incomparably various and grotesque--in some instances sublime. The valley of Green River at this point is a cheerless sage-brush desert, as it is further north. To be sure, this uninviting stream, a couple of hundred miles further south, having united with the Grande, and formed the Rio Colorado, does indeed, by dint of burrowing deeper and deeper into the sunless chasms, become at last sublime. But here it gives no hint of its future somber glory. I remained awake till we had crossed Green River, to make sure that no striking scenery should be missed by sleep. But I got nothing for my pains except the moonlight on the muddy water; and next time I shall go to bed comfortably, proving to the conductor that I am a veteran and not a tender-foot.

In the morning, we breakfasted at Cimarron, having in the interval passed the foot-hills of the Roan Mountains, crossed the Grande, and ascended for some distance the Gunnison, a tributary of the Grande, the Uncompahgre, a tributary of the Gunnison, and finally a branch, flowing westward, of the Uncompahgre. A high divide at the head of the latter was laboriously surmounted; and then, one of our two engines shooting ahead and piloting us, we slid speedily down to Cimarron. It is in such descents that the unaccustomed traveler usually feels alarmed. But the experience of the Rio Grande Railroad people is, that derailment is likely to occur on up-grades, and almost never in going down.

From this point, comparison with the Union Pacific line in the matter of scenery ceases. As everybody knows, that road crosses the Rocky Mountains proper in a pass so wide and of such gradual ascent that the high summits are quite out of sight. If it were not for the monument to the Ameses, there would be nothing to mark the highest point. For all the wonderful scenery on the Rio Grande road, between Cimarron and Pueblo, the Union Pacific in the same longitudes has nothing to show. From an artistic stand-point, one road has crossed the ranges at the most tame and uninteresting point that could be found, and the other at the most picturesque.

At Cimarron, the road again strikes the Gunnison, and plunges into the famous Black Cañon. In length, variety, and certain elements of beauty, such as forest-ravines and waterfalls, this cañon surpasses the Royal Gorge of the Arkansas. There is, however, one spot in the latter (I mean, of course, the point where the turbulent river fills the whole space between walls 2,800 ft. high, and the railroad is hung over it) which is superior in desolate, overwhelming grandeur to anything on the Gunnison. Take them all in all, it is difficult to say which is the finer. I have usually found the opinion of travelers to favor the Gunnison Cañon. But why need the question be solved at all? This one matchless journey comprises them both; and he who was overwhelmed in the morning by the one, holds his breath in the afternoon before the mighty precipices of the other. To excuse myself from even hinting such folly as a comparison of scenery, I will merely remark that these two cañons are more capable of a comparison than different scenes usually are; for they belong to the same type--deep cuts in crystalline rocks.

Between them come the Marshall Pass (nearly 11,000 ft. above sea-level), over the continental divide, and the Poncha Pass, over the Sangre di Cristo range. This range contains Harvard, Yale, Princeton, Elbert, Massive (the peak opposite Leadville), and other summits exceeding the altitude of 14,000 ft. To the east of it is the valley of the Arkansas, into which and down which we pass, and so through the Royal Gorge to Cañon City and Pueblo, where we arrived before dark on the day after leaving Salt Lake.

Salt Lake, the Jordan Valley, Utah Lake, the Wahsatch, Castle Cañon, the Black Cañon of the Gunnison, Marshall Pass, Poncha Pass, the Arkansas Valley, the Royal Gorge--what a catalogue for so brief a journey! No wonder everybody who has made it is "wild about it!" If enthusiastic urgency of recommendation from every passenger has any influence (and I know it has a great deal), this road will continue to be, as it is at present, crowded with tourists. It furnishes a delightful route for those who wish on the overland journey to see Denver (as who does not?) and to visit Colorado Springs and Manitou. All this can be done _en route_, without retracing the steps.

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PHOTOGRAPHY APPLIED TO TERRA-COTTA AND OPAL GLASS.

In the natural course of things it must necessarily have occurred to practical men to utilize photography in the case of terra-cotta, as it has already been employed in connection with so many other wares; but I have not to this day known of its successful application to terra-cotta. Now this is strange, if one considers how fashionable _plaque_ and plate painting have become of late, and the good photographic results that are easily obtained on these as on sundry articles of this same "burnt earth." Portraits, animals, landscapes, seascapes, and reproductions are one and all easily transferred, whether for painting upon or to be left purely photographic. As a matter of business, too, one fails to see that it would not be remunerative, but rather the contrary. It was with something of this feeling that I was led to try and see what could be done to attain the end in view, and as I knew of no data to go by, I had to use my own experience, or rather experiment on my own account.

Since emulsion was constantly at hand in my establishment, in the commercial production of my gelatine dry plates, it was but natural I should first have turned to this as a mode of obtaining the desired results; but, alas! all attempts in that direction signally failed--the ware most persistently refused to have anything to do with emulsion. The bugbear was the fixing agent or hypo., which not only left indelible marks, but, despite any amount of washing, the image on a finished plate vanished to nothing at the end of an hour's exposure in the show window. There was nothing left but to seek other means for the attainment of my object. I would not have troubled the reader as to this unsuccessful line of experiment but that I wished to put him on his guard and save him useless researches in the same direction. To cut matters short, the method I found best and most direct was the now old but still excellent wet collodion transfer. I will now proceed to detail my system of working to facilitate the matter to the inexperienced in collodion transfer.

TERRA-COTTA PHOTOGRAPHY IN PRACTICE.

The first and indispensable operation, in the preparation of the surface to receive the transfer, is the "sizing of the surface." It simply consists of a solution of gelatine chrome-alumed, as follows:

Gelatine. 10 grains. Water. 1 ounce. A trace of chrome alum.

Coat with a soft camel's hair brush and let dry. It is needless to say that numbers of _plaques_, plates, vases, etc., may be coated right off, and will then be ready for use at any time.

Having settled on the subject and carefully dusted the negative, as well as placed it _in situ_ for reproduction, the next thing required is a suitable collodion, and the following will be found all that can be desired:

TRANSFER COLLODION.

Cotton. 3 drachms. Iodide of cadmium. 65 grains. Ammonium iodide. 25 " Bromide of cadmium. 19 " Ammonium bromide. 11 " Alcohol. 15 ounces. Ether. 15 "

The plate thoroughly cleaned and coated with the collodion is now transferred to a bath, as follows:

Nitrate of silver (common) 25 grains to the ounce.

Made slightly acid with nitric acid.

After sensitizing, the plate is exposed in the usual way and taken to the room where pictures are ordinarily developed, and _quantum suff_. of the following poured into the developing cup to bring out the image:

DEVELOPING SOLUTION.

A Winchester of water, i.e. 80 ounces. Protosulphate of iron. 240 grains. Citric acid. 240 "

Or the following may be used:

Pyro 3 grains\ Citric acid 2 " } per ounce of water. Glacial acetic acid 30 drops /

After perfect development the picture is well washed and then fixed in a saturated solution of hypo.; after which it is thoroughly washed.

It will now be found that the picture is not altogether satisfactory; it lacks both vigor and color. To improve matters recourse is now had to

TONING.

Gold. 1 grain. Water. 5 ounces.

With this a very fine depth is soon attained, and a nice picture the result. Leave out the toning, and only a poor, sunken-looking picture will be the outcome; but directly the toning bath is employed richness at once comes to the fore. I have, however, known of instances where the picture needed no toning.

OPAL PRODUCTION IN PRACTICE.

This is still a secret with some in the profession. A limited number of workers have succeeded in bringing out good opals, and their _modus operandi_ is kept from the many. Now this is a pity, when one considers the great charm attached to a good picture on opal, with pure whites and rich blacks, and in many localities the demand that might be created for them. Apart from their beauty, another charm attaches to opals--their absolute permanence; and this, it must be allowed, is no trifle. What, in fact, can be more painful to the worker who values his work, and sets store by it, than to feel it must ere long fade and pass into oblivion! A properly executed opal will no more fade than the glass pictures so common at one time, and which, wherever taken care of, are as perfect now as they were when first taken.

Now, excellent pictures are to be made on opals by means of emulsion; but I propose first taking the transfer method (mainly applicable to ground opal and canvas) as given above for pottery, since in practice it is found very ready, easy of manipulation, and safe. The details are much the same as above, and necessitate double transfer.

After the picture had been obtained on the plate (ordinary glass plate), and after thoroughly fixing, washing, and toning, the picture (and this, remember, is the case likewise with terra-cotta) then has to be loosened from its support, and this is done with a solution of sulphuric acid--one drachm to fifteen ounces of water--which is made to flow between the image and the glass, after which perfectly wash and mount. When the image is loosened a piece of tracing paper is put on the image, evened out, raised (assisted by some one else to hold the two opposite corners during the operation), and with the aid of the helper the picture is carefully centered, gently pressed out or down, and the transfer is so far effected. But what will happen, and does happen, in the case of vignettes, is impurity of the whites, when the picture becomes positively objectionable. Now the way to remedy this lies simply in the application, to the dirty-looking parts, of a solution of iodine dissolved in iodide of potassium to sherry color; after which, well wash and apply a weak solution of cyanide of potassium, and wash well again. This, by the way, is equally applicable to paper transfers; and it is to be remembered that the toning comes last of all. It is a rather difficult matter to clean a ground opal which has been used two or three times, and acid must then be had recourse to (nitric acid is as good as any); but by transferring from the support on the ground surface, all stains are at once avoided.

On the flushed glass, or on the pot metal (unground), after well cleaning the surface it should be covered with a substratum of egg. Then the picture is taken direct, not transferred; that is, the plate is exposed direct in the camera, regularly proceeded with, and, when dried, varnished with a pale negative varnish, or with dead varnish if intended for chalk or water-color. This, when a good negative is used, gives a remarkably fine picture, not requiring a vestige of retouching, and having likewise the invaluable advantage of being perfectly durable if varnished with the negative varnish. Moreover, on that, effective pictures may be made in oil with simply tinting.

A gentleman, who has a right to be considered a good judge in all art matters, on looking at one of these pictures transferred on flushed glass, said it was one of the finest productions of photography. He urged that negatives _ad rem_ should be taken most carefully, and that, like the picture I showed him, they should be full of half-tone and detail, and yet have plenty of vigor. They should, he said, be robust in the high lights, have perfectly clear glass in the few points of deep shadows, and thus have powerful relief. Moreover, the negatives should be retouched only by a competent hand, and care taken that the likeness shall be in no way altered, which is so frequently the case now.

If done as thus suggested there is no doubt that remarkably fine pictures are to be produced on opal, whether ground or not. Most artistic results are to be obtained, and, with proper care, absolute permanency. In this age of keen competition, all have to think of what may be really recommended to one's _clientèle_, and likely to meet with approbation from strangers and friends when the picture has once been delivered; and I candidly think that the opal, of all, is the picture most likely to meet with this general approbation.

I hope I have left it clearly to be understood that the class of opal picture to which I have chiefly alluded is one that remains untouched after the transfer--that is, absolutely unpainted upon. It is pure photography in every sense of the word, and the resultant picture one hardly to be surpassed in any way. I have rather laid a stress on this point, well knowing how pictures are at times irretrievably ruined by the barbarous hand of would-be artists, who by far exceed the true artists in number; and the hint on retouching should not be lost sight of, either, at a period when the tendency is to stereotype every one in marble-like texture, or rather lack of texture, as if the face were devoid of all fleshiness and as hard and rigid as cast-iron. It might be wise to weigh this point carefully, and act upon it, before the enlightened public have raised a cry against the pernicious practice and made photographers smart for their want of applying timely remedial measures to a decided evil.

On reading the above again, fearing lest any misconception should arise in the mind of the reader, I deem it expedient, to clearly state that for terra-cotta recourse is had to double transfer; that is, the picture first taken is lifted from the support on tracing paper, put in the right position on terra-cotta, and pressed down while wet with blotting-paper, left to dry, and is then so far ready.