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del Macho, a point 65 miles distant from Vera Cruz, at which, during the last year, a small town of more than 2,000 inhabitants has sprung up, with schools, hotels, a railway station, and all the other evidences of a state of progress and civilization which we find germinating along the path of the railway in the expanding regions of our own Western domain.

To appreciate fully the progress made since that date, of which progress the opening of the line between Mexico and Apizaco is the immediate and striking proof, it is necessary for the reader to bear with us while we sketch out for him hastily the enormous, the literally enor. mous difficulties in the way of this gigantic railway enterprise.

As the crow flies, Mexico City lies at a distance of about 200 miles frem Vera Cruz. But while Vera Cruz is seated on the edge of the ocean, Mexico City is situated on a height of no less than 7,340 feet above the sea-level. Ilad it been found practicable to build a railway of uniform ascent from Vera Cruz to Mexico, therefore, it would have ben necessary to give that railway an ascending incline of no less than 364 feet per mile, à piece of engineering work which might well appal the inexperienced and give the most experienced "pause. But even this was not preticablo. Between Vera Cruz and Mexico a point must he passed much higher than the elevation of Mexico itself. The country, which intervenes between the two may be described as made up of two great plateaux, united by an inclined plane—the lower plateau averaging about 700 feet, and the upper about 8,000 feet in elevation above the sea-level. Between these two plateaux is a distance of about fifty-five miles, which distance is broken up into lofty and rugged chains of nountains called in the country Cumbres, which form the eastern flank of the upper plateau. The width of the lower plateau itself is just about equal to that of this intervening space, orfifty-five miles; and consequently, the ascent to the level of the upper plateau had to be accomplished within a distance of 110 miles from the coast, a feat absolutely without paraellel in railway experience, and the proportions of which will be more fully comprehended when we remember that in travers. ing the lower plateau which takes the road over one-half this distance, or fifty-five miles, the engineers reach an elevation of only 1,500 feet, leaving them to master à further elevation of nearly 7,000 feet within the succeeding 55 miles to the crest of the Cumbres above spoken of.

Here, then, was the problem of the railway, to accomplish an ascent of 6,540 feet in 55 miles, corresponding to 119 feet per mile, or two feet in 414 feet throughout the whole distance.

The following table of the severest ascents heretofore known in railway engineering will give the most accurate idea possible of the task imposed upon Colonel Talcott and M. Lloyd. Ascept.

Railway.

Feet per mile.
The Giori Incline
Turin & Genoa, Italy..

117 for 6 miles. The Semmering Vienna & Trieste, Austria.

113 for 13% miles. Tbe Chinarcito .Copiapo, Chili.

196 for 13 miles The Taboo .Valp. & Santiago, Chili

120 for 12 miles. The Allegheny Baltimore & Onio, t. s..

117 for 11 miles. But even these figures do not fully set forth the extraordinary pature of these great works in Mexico; until we take into the account that whereas the most abrupt ascent ever before achieved, that of the Chanarcillo on the Copiapo line in Chili, is of 196 feet in 13 miles, the chief incline of the Imperial Mexican Railway at Maltrata near Orizaba will overcome 211 feet per mile in a distance of 23 miles. In achieving this part of the works, the engineers have been called upon to construct over the river Metlac, midway between the cities of Orizaba and Cordova, a viaduct which, when completed, will surpass any structure of the kind now existing in the world, and will, of itself, be well worth a trip to Mexico to see. This viaduct, to consist of an iron bridge, now constructing and nearly completed in England, will carry the road over the Barranca de Metlac, at the enormous height of 380 English feet being nearly 150 feet higher than any such work now extant, so that it, would be possible to pile upon the spire of Trinity Church the spire of Grace without reaching the roadway sustained upon its magnificent arches.

Some notion of the strictly engineering difficulties of the work undertaken by the Imperial Mexican Company, and to be completed, according to the terms of its contract with Crawley & Co., before the 30th April, 1869, may be derived even from these brief statistical netes. But when the reader reflects further that all the most important materials, the rails, the working tools, many of the supplies for the great bodies of worhmen to be employed on the line, not only up to these heights vf the Cumbres, but far beyond them upon he upper plateau, stretching from the Cumbres by Puebla to Mexico, must be imported from Europe and America, and tansported hundreds of miles on the backs of mules, or in the wide broad-wheeled wagons of the country over the most execrable roads on earth, he will readily agree with us, that when the Imperial Company in June, 1866, can point to more than 160 miles, or over half their whole line opened to commerce, they may fairly claim to have accomplished as handsome a year's work as men need be called upon to do. In accomplishing this, the Company have expended, for example, more than a million of dollars upon the transportation of rails alone from the coast to the line on the upper plateau." They have employed, and now employ, a total force in all departments of about 10,000 persons; they are receiving rails and other materials in the port of Vera Cruz at the rate of about 2,000 tons per month. England having recognized the de facto Imperial Government at Mexico, the vast business connected with this enterprise, which naturally and under ordinary circumstances would have inured to the benefit of American industry and capital, has, of course, been chiefly carried on the profit of Great Britain. American engineers are, however, employed under Col. Talcott on all parts of the walls, the difficult section of the Chiquihuite, on the edge of the tierra caliente, or tropical region, being under the charge of Mr. Deckert, of Pennsylvania, an engineer who has learned in Cuba to make light of the vomito, and to keep a cool brain under the hottest suns.

The opening of the upper sections between Mexico and Otumba, and Otumba and Apizaco, will give an immediate impulse to the intercourse between the two great cities of Puebla and Mexico, and to the development of the extensive intervening country. In conjunction with the lower section, already in operation between Vera Cruz and Paso del Macho, passengers from Vera Cruz to Mexico will thus be enabled to make their journey in two days, instead of three, and light goods, which now require three weeks in the transport, will be forwarded in six days. Such a consummation may truly be regarded as a great and glorious victory won for civilization and true progress in Mexico. Whether under the banner of an Empire or the banner of a Republic, the “road-maker" is the true benefactor of nations, the true precursor and prophet of liberty, and all good things which come with liberty, wisely understood and wisely practiced.

SYSTEME METRIQUE. MODERN commerce bas encountered no greater obstacle to its progress than the multiplicity of weights, measures and moneys used in its prosecution. Not alone the great nations of the world, but every petty principality and power, until recently had their own denominations and values, differing greatly from one another and only translatable through the aid of voluminous dictionaries compiled from elaborate comparisons. Such a condition of affairs might be tolerated in the primitive eras of nations, before travel and national interchanges of products became the great business of the human race; but in the present era, when the railroad and steamship carry passengers and freight with the swallow's pace, and when the commingling of nations makes the world as a single brotherhood, something more simple and universal in its functions is demanded, which the denizens of each and every nation, however foreign to each other in language, can easily comprehend. The great want has been and still continues in a measure to be a universal system, with a nomenclature, founded on the ancient Greek and Latin, languages in universal use. The adoption of such a system was one of the first acts of the French Revolutionary government, which in 1799 proclaimed the Systeme Metrique. It has since boen adopted either wholly or partially, and its use become permissive or obligatory in almost every civilized country. We ourselves have for many years used it in scientific processes, and are now about to bring it into ger.eral use. A bill to this effect is before Congress, and has already been sanctioned by the Representatives ; and there appears to be little doubt but that the bill will finally become a law, and the system in a short time be popularized throughout the Union. The change demanded by the new system will come easier to ourselves than to nations wholly accustomed to multiply and divide by the binary process. We have learned the decimel mode of proceeding from our own money system, and hence to carry its application to weights and measures will soon become familiar. Oiberwise than this, the change contemplated by the present law is without complexity, being simply the substitution of one unit of value for another. What follows will explain the whole subject.

HARMONY OF THE FRENCH SYSTEM. Though decimal weights and measures will be new to this conntry, they are not new to the world. They originated in France three quarters of a century ago, where they have been fully tested in the crucible of commerce ; and the system there adopted has been proved to be the best that it is possible for man, aided by science, to devise. In France it has had the best trial it is possible that it could have; for it is only in a country where he monetary and metrical systems are both decimalized that it could be horoughly tested. When the United States created its decimal currency, ind left its weights and measures unaltered, it did not even carry out a alf measure of reform. Sterne's proverbial dictum, that "they do these bings better in France,” was never a greater truism than in the natter of her change to a decimal system. She did not pull down and ebuild the half of an edifice, and present a structure, one half of which lid not accord with the other, but tore down the entire of the old fabric, and erected a new one that harmonized in all its parts.

THE ADVANTAGE OF ADOPTING THE FRENCH SYSTEM. It is the French system of weights and measures that we are about to introduce. By adopting its units, which are founded on scientific data, there is no placing an additional clog in the wheels of commerce, which would undoubtedly be the case if a new system were introduced with other units, although that system were a decimal one.

It is evident that the French system must, in the course of time, become universal, and the sooner we thoroughly adopt it—that is, make its use compulsory—the sooner we shall place ourselves on the smooth road upon whicb all nations must eventually travel. The nomenclature, too, being derived from the Greek and Latin, renders it applicable to every modern iongue, and thus prevents the necessity of each country drawing from its own lingual store names for new weights and measures which would not be understood beyond its boundaries. The advantage in commercial traps. actions of a universal system with a universal nomenclature is obvious.

THE ORIGIN OF THE DECIMAL SYSTEM, The history of the inception and introduction of the metric system is a matter of much interest. It imparts to us a knowledge of the substantial foundation upon wbich it rests, and the care which was bestowed to arrive at a system in strict accordance with the laws of science. We have no space, however, to enter into a detailed account of the difficulties that beset the path of those who were engaged in reducing the theory into practice ; but when we state that the requisite surveys and experiments were carried on in the most exciting period of French history, the result proves how successfully earnest and intelligent men are able to overcome, what to others would be insurmountable, obstacles. Their labors began a year or two before the commencement of the revolutionary struggle, and did not terminate until the last year of the century.

The ancient French system of weights and measures presented no uniformity; there was no relation between the pied, used as the unit of the measure of length, and the liore, as that of weight; and even although those measures bore the same denominations in all provinces, they were very different in their proportions in particular districts—the diversity being, to use the epithet of Delambre, scandalous. Local consuiners did not feel the whole disadvantage which arose, but merchants often experi. enced great difficulties in converting to their own local standard the qualities expressed according to another rule.

One of the first objects which engaged the attention of the general States in 1788, was to find a remedy for this defect. It was then agreed VOL. LV.NO, I.

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that some principle should be established, on which a new system should be founded. It was desirable to find a natural and invariable standard; and it may be observed that mankind, in all ages, bave been endeavoring to obtain some such result, though they may have proceeded without accu• rate scientific knowledge. Without science it is impossible to find an invariable standard in nature ; for there is such ingivite variety in the individual character of her productions that no portions of animal or vegetable malter ean be found of equal or unehanging dimensions. It was therefore the object of the French to establish, "as the fundamental unity of all measures, a type taken from nature itself

, a type as unchangeable as the globe upon which we dwell

, to prepare a metrical system, of which all the parts should be intimately connected, and of which the multiples and subdivisions follow a natural progression, which would be simple, easy to comprehend, and worthy of the enlightened age in which they lived.”

THE UNIT DECIDED UPON.

The Academie des Sciences was first requested to determine the length of a pendulum, vibrating seconds according to given rules, under certain circumstances. But this was objected to, because it was thought that the result, depending upon the weather and arbitrary division of time, was not susceptible of the requisite accuracy. It was then agreed to adopt the ten millionth part of the fourth part of the meridian, or of the quadrant comprised between the Equator and the North Pole, for the unity of this measure of length, and to derire all others from this standard.

PRINCIPLES 07 THE METRICAL SYSTEM,

It was then proposed that the new system should be founded upon the following prineiples :

1. That all weights and measares should be reduced to one uniform standard of linear measure.

2. That this standard should be an aliquot part of the cireumference of the globe.

3. That the unit of linear measure applied to matter in its three modes of extension, length, breadth, and thickness, should be the standard of all measures of length, surface, and solidity.

4. That the cubic contents of the linear meas are in distilled water, at the temperature of its greatest contraction, should furnish at once ibe standard weight and measure of capacity.

5. That for everything susceptible of being measured or weighed, there should be only one measure of length, one weight, one measure of contents, with their multiples and subdivisions exclusively in decimal pra portions.

6. That the whole system should be equally suitable for the use of all mankind.

7. That every weight and every measure should be designated by an appropriate, significant, characteristic name, applied exclusively to itself.

Thus it will be observed, according to this scheme, tbe unit of linear measure is the basis of the whole system. For the purpose. of obtaining the value of the unit, it was resolved that an arc of the meridian should be actually measured. M. M. Mechain and Dclambre were therefore ap

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