ART. NUMBER IV. CONTENTS OF No. IV., VOL. XLVI. PAGE I. SOMETHING ABOUT SILK.-0. A. W.,................. 821 II. POST-OFFICE FINANCES. How has the Postal Revenue been affected by reducing the rates of postage? BY PLINY MILES,...... 329 III. HARBOR DEFENCES ON GREAT LAKES AND RIVERS. Harbor Defences on Lakes and Rivers proposed as a measure likely to promote peace-Rapid advance in prosperity of Northwestern States-Increase of Population-Value of Real and Personal Property-Increase in Political Power-Tonnage and Valuation of Vessels engaged in Commerce of Lakes and now building-Aggregate of Imports and Exports of Lake Towns-The great importance of the Northwest, and the little aid it has received from the Federal Treasury-Plan of Defences: First. The establishment of Shore Defences. Second. The establishment of a National Foundry on the Upper Lakes. Third. The Enlargement of the Illinois and Michigan Canal for Military purposes,. 837 STATISTICS OF TRADE AND COMMERCE. 1. Trade and Commerce of San Francisco. 2. Chicago and its Trade for the past Year. 8. Toledo-its importance-the Shipments and Receipts for 1861 compared with previous Years. 4. Trade and Commerce of Buffalo. 5. Flour and Grain in France-official table. 6. Importations of Flour and Grain into Great Britain and Ireland for fourteen years, 18481861, JOURNAL OF MINING, MANUFACTURES AND ART. 1. Iron Manufacture of the United Kingdom. 2. Law relating to Dealers in Old Metals in Great Britain. 3. Anthracite Coal Trade of the United States. 4. Annual Review of the Lake Superior Copper Mines,...... 857 371 THE COTTON QUESTION. 1. Surat no Substitute for American Cotton. 2. Liverpool Cotton Report. 3. Acquisition by England of Lagos, and the Treaty between Great Britain and DOCEMO, King of Lagos. 4. French Stock of Cotton. 5. Cotton in the United States,.... JOURNAL OF BANKING, CURRENCY AND FINANCE. 1. City Weekly Bank Returns, New-York, Philadelphia, Bostop and Providence. 2. Weekly Statement Bank of England. 8. Note Circulation of the United Kingdom. 4. Returns of Bank of France. 5. Quarterly Statement of the Banks of Ohio. 6. Public Debt of the JOURNAL OF NAUTICAL INTELLIGENCE. 1. Gallantry Light-House, Newfoundland. 2. Fixed Light on Zafarana Point, Red Sea, Gulf Proper classification under Tariff Acts, of certain Articles of Foreign Manufacture and Pro- duction-Abstract of the Postal Bill introduced by the Hon. JOHN HUTCHINS, in the House Federal Finances-Loan Law of February-Certificates of Indebtedness-Interest payable in Coin-Demand Notes-Receivable for Duties-Deposits at Five per cent.-Clearing- House Returns-Loan of March 17-Means of the Department-Interest on Three Year Bonds Supply of Money-Banks Dispose of Government Loan-Commercial Loans- Great Reduction-Private Deposits-Rates of Money-Capital Idle-General Laziness-- Improved Trade-Agricultural Prosperity-Army Pay Promotes Trade-Imports and Ex- ports-Specie Shipments and Receipts-Prices of Bills-Money Abroad,..... THE BOOK TRADE. THE MERCHANTS' MAGAZINE AND COMMERCIAL REVIEW. MAY, 1862. THE MINING AND AGRICULTURE OF MEXICO. BY A. K. SHEPARD. EVEN in the present difficulties which beset us as a nation, we cannot but look upon the events which are transpiring in Mexico with the greatest interest. Aside from the claims upon our attention, originating from its political condition, its peculiar natural advantages serve to render it the most attractive of countries. The traveller by the diligence, within a few hours after leaving the hot sand-hills of Vera Cruz, passing through the fertile valleys of Cordova and Orizava, filled with the rich vegetation of the tropics, upon approaching the table-lands of the interior, finds himself in a climate of perpetual spring-time. Advancing to the base of the Anahuac Mountains, the cold blasts from the peaks of the "White Maiden" and the "Smoking Mount," and the surrounding forests of pine, forcibly remind him of our northern latitudes. And this change, from the region of palms to that of pines, has been effected by a journey of but two hundred miles. The line of perpetual snow in the latitude of the valley of Mexico lies at an elevation of about 14,000 feet above the level of the sea; and there are three lofty peaks, Popocatepetl, Ixtlaccihuate and Orizava, whose summits are some 4,000 feet above this line. Orizava, as seen from the coast, among the broken masses of the Cordillera, was considered by HUMBOLDT the noblest peak on the continent. All of them are visible at once from portions of the plain of Puebla, each being higher than Mont Blanc by some 3,000 feet. Although at their great altitude the atmosphere is so rarified that but few white men have accomplished their ascent, the Indians of the district are constantly at work in the crater of Popocatapetl, from which they obtain great quantities of sulphur. The hotels of the capital are also supplied with ice from the same source, though from the outside of the mountain. The Cordillera mountains traverse the country in a northwesterly direction, and by following the 19th parallel of latitude from the Gulf of Mexico to the Pacific, we find not only the greatest general elevation from coast to coast, but also in its vicinity the highest peaks of North America. To the north of this line the country gradually becomes even. Near San Luis Potosi and Monterey large plains intervene between the short ranges into which the mountains are broken, and these plains decreasing in elevation, gradually swell into the broad prairies of Texas. Towards the south there is also a general descent, though a more broken country, till we reach the Isthmus of Tehuantepec. It is on the western slopes of these mountains that, as if in compensation for their sterility, some of the richest silver mines are found, while on the Atlantic side, with a comparative scarcity of precious metals, the vegetable products are such as to render it the most prolific region of North America. Here the winds, which prevail from east and northeast, deposit the moisture which they collect in their passage over the Atlantic and Gulf of Mexico, enriching the alluvions of the coast, but, being stopped in their progress by intervening mountains, leave to the table-lands a more arid climate. Mexico has always been distinguished, above other countries, by its mineral wealth. Since the days when CORTEZ and PIZARRO plundered its natives, and those of Peru, of their treasures, those two countries have been the greatest silver-producers of the world. Of the two, Mexico possesses the advantage of having her mines more favorably situated, and at lower elevations, which admits of their being worked with more profit. They yielded, from 1805 to the time of HUMBOLDT's visit to the country, according to that author's estimates, $2,027,955,000-over two thousand millions of dollars! It is, perhaps, a little singular, that with all the gold which was found in the country by the Spanish conquerors, so little should be found at the present time. That the metal so common among the Aztecs was found nearer their own valley than California, there is little doubt, and that gold may still be obtained in such quantities as to well repay the labor of getting it, is quite certain. While upon the Isthmus of Tehuantepec, some four years since, the writer learned, from sources every way reliable, that "placers" existed on the Uspanapa River, which has its rise among the mountains of Chiapa. In 1857 a survey of the States of Guenero and Michoacan was undertaken, mainly for the purpose of finding coal, which could be taken to Acapulco for the use of the Pacific steamers, and thus save a portion of the immense outlay now necessary to provide those vessels with fuel. Although not successful in the main object of the expedition, the party reported a country rich in precious metals-a region which had never been thought to possess peculiar advantages. Nor are these the only accounts of the mineral wealth of some of the more sparsely inhabited districts, which are known to possess unopened mines of surpassing richness. The most celebrated mines are those of Real del Monte, Pachuca and Catorcę, in Central Mexico; Zacatecas, Durango and La Candelaria, in Northern Mexico. The Valenciana shaft, near Guanaxuato, has been excavated to a depth of 1,800 feet, and many others are worked with profit at depths from 1,000 to 1,500 feet. In the celebrated Candelaria mine, near Durango, where a depth of 800 feet had been attained, the water was still kept from the shaft by Indians, who carried it to the surface in raw-hide sacks, climbing up notched poles. Yet, with such rude management, the mine yielded, for five years, an annual profit of from $124,000 to $223,000. The Arevala mine produced, in seven weeks, in 1811, a clear profit of $200,000. The greater part of the produce of the mines near the Pacific coast finds its way to England; the smuggling operations in bullion being enormous, often carried on under the protection of British ships of war. Quite recently new mines have been discovered in the vicinity of Monterey and Saltilla, but the ore is generally so impregnated with lead as to render the extraction of that metal of more importance than that of the sil ver. Many of these are in the hands of Americans, whose smuggling operations across the Rio Grande rival those of the English on the Pacific. Owing to the perpetual revolutionary disturbances, and the general insecurity attendant upon them, many mines which were formerly worked with profit have been abandoned, and their shafts and galleries are filled with water. Many mining cities of the north which were, according to the writings of the old Spaniards, opulent and important, have now dwindled down to mere villages, whose inhabitants are in constant fear of the Camanches. Even those mines which are now being worked are managed in such a rude and inefficient way as to cause one to wonder at the wealth they produce. It would be difficult to form an estimate as to what they would yield if submitted to that energy which has been pouring the treasures of California upon the world. The most primitive contrivances are generally in use for excavating the ore, and afterwards for crushing it previous to the process of extracting the silver; but it is this most important part of the labor which is usually conducted the most inefficiently. Ores having a silver produce of less than 60 ounces to the ton are generally smelted; those containing 70 to 80 ounces are amalgamated with mercury, as the best way of separating the silver from the earth and base metals with which it is found combined. Several things are to be taken into consideration before deciding whether a particular ore is best adapted to smelting or to amalgamation. If the ore contains large quantities of lead or copper, it should be smelted, as only the precious metals combine readily with mercury, and the lead or copper would be lost by the amalgamation process. Ores, containing sulphur or iron pyrites, yield decidedly more silver upon being amalgamated, as sulphur is essential to the success of the process. By the old Mexican method of effecting the amalgamation of the silver with mercury, the ore and other ingredients are placed in a " patio," or paved court, and exposed to the trampling of mules till the combination takes place. The operation is very tedious, and is sometimes attended by the loss of all the metal under treatment. |