their gold from the flanks of each of its outlying spur, and of the central spur being sterile of precious metal. Rivers flowing through transverse valleys are, generally speaking, more rapid than rivers flowing through longitudinal valleys; hence gold-dust is sometimes scarce in the former, having been hurried down by the speed and force of the current to the longitudinal valleys, and often borne a considerable distance along these. The point at which the gravity of the metal began to exceed the force of the current, and to deposit itself, may, it is evident, leave many a sterile place in the sands of the same river, both above and below the rich auriferous deposit. This point must generally be determined by actual exploration on the spot; but these circumstances do not occur so generally as might, à priori, be deduced; for the quantity of auriferous deposit brought down may have varied at different times and at different seasons, as may also the volume of water and the force of its current. We all know there may be rises and floods in every mountain stream. It is evident that in such cases both new auriferous sites may be explored and acted upon, and the detritus both of that and of older deposits may be carried much further down the river. Then, again, it is not a phenomenon the result of one flood or of one cataclysm, as some geologists would lead us to suppose, but of actions constantly going on; so that one party of washers may be working the deposits of extraordinary winter floods, another that of less violent risings, another that of ordinary but successive winters, another, finally, the most recent deposits of all, and each with various degrees of success, as they guide themselves by the peculiarities of the river and of its current. When auriferous sands are met with in the beds of rivulets in transverse valleys, there are greater chances of finding the native gold in its original site than in longitudinal valleys, and these chances will be increased in proportion as the valley is limited in extent both ways, that is to say, in length and breadth. Transverse rivulets often flow through more or less perpendicular ravines, but this is more general when they pass from one longitudinal valley to another, or to the open country, than near their sources. As these sources are generally in the primitive and nonauriferous axis of mountains, the second order of transverse valleys, where the rivulets cut at angles through the upraised metamorphic rocks, are most likely to be productive; and, for the same reasons, rivulets flowing along longitudinal valleys of the second order, that is to say, not such as flow between the primitive axis and the first outlying range of metamorphic rocks, but such as flow between the first and second outlying ranges of metamorphic and sedimentary formations, are most likely to be productive. But even this has an exception, inasmuch as longitudinal valleys of the first class may be, but are rarely so, supplied with gold from the outlying metamorphic formations. When, in addition to a simple axis of elevation and outlying ranges and spurs of metamorphic and sedimentary rocks, there are also indications of successive periods of eruption, in the cropping out to-day of porphyries, trachytes, basalts, greenstones, and other igneous rocks, and the outlying ranges have been broken up and tilted into a variety of forms and shapes, presenting a perplexing disposition and a highly contrasted configuration, the study of these phenomena becomes more complex ; but still not so to a geologist with a clear head on his shoulders, and who would always set to work mapping down his country, determining the relation of the valleys to the central and outlying axis of elevation, eliminating order from apparent disorder, and having science and safe grounds to back him when he first gives his opinion as to where the miners' operations may be carried on with most chances of success. Auriferous alluvia have, then, the same origin as the sands of rivers containing gold; the particles have accumulated there during a long series of ages, and have concentrated themselves there in different manners, according to the varying intensity of the action of waters. Sometimes we have great valleys perfectly level, in which the torrents have spread themselves uniformly, forming vast sheets of running waters, the current of which diminishes in proportion as they gain in extent; sometimes we have a plain diversified by hills, which indicate in their rather devious parallelism the basins adopted and afterwards abandoned by the currents of water. The soil of these great sablonous deposits is formed of the detritus of the neighbouring mountains-fragmentary, rolled, rounded detritus, in the powder of which the particles of gold are disseminated in masses irregularly concentrated, and in beds of different richness. The auriferous sands of alluvia are generally at a greater depth than those which belong to running waters. There exist in the Altaï some deposits at such a depth, that it is necessary to work them by means of wells and subterranean galleries. Such are the mines in the valley of Koundoust-ouyoul. The relative antiquity of alluvia may be, to a certain extent, appreciated by their nature. Those of a perfectly recent character have little or no consistency. Such are the sands of the valley of the Nile, even in the part which its floods do not reach; such are also those of the Golden Terrace, in the centre of Africa. The looseness of the sands in the deserts of Asia and Africa would appear, however, in some cases, to be owing to other circumstances than their recent deposition. Among these, the chief would seem to be the want of water, to act upon whatever iron or lime is present, and which, by disintegration or decomposition, becomes a means of cohesion to mud and sands. This state of things is further entertained by the great heat and extreme dryness of some portions of these continental spaces. It is not certain that some of the moving sands of Asia and Africa may not be as old as the oldest alluvia. It sometimes happens that the alluvia contain wood buried in them in the most perfect state of preservation. The washings on the banks of the Bourlevskaïa, on the south-west slope of the Alataou Mountains, in Siberia, contain trunks of trees so well preserved as to be almost green. Beyond Falamah, near the country of the Bambuchs, the auriferous sediments are mixed up with fragments of quartz, and the sands alternate with a yellow earth in which siliceous pebbles and bits of oxide of iron are dispersed. The valley of the Sil, in Galicia, is blocked up with a conglomerate formed of large cakes of quartz imbedded in clay and sand, and which proclaim a greater age and the beginning of adherence. The casalhos of Brazil, especially those which are mined at Jaraqua, four leagues from Saint Paul, in the capitanerie of the same name, are conglomerates of some solidity, composed of rolled pebbles of quartz and gravel, which indicates an ancient alluvium, is covered by a vegetable earth, and in which (the conglomerates) the gold is disseminated in grains of various size. These deposits, called red deposits, are deeply coloured by oxide of iron, which constitutes their cement. In the Altaï, on the borders of the Kiy, beds of auriferous alluvia are mined by subterranean galleries, at a depth of from twenty-five to forty feet. These beds are covered with sedimentary formations which belong to the oldest epochs of the quaternary era; they are remarkable for the size of the grains and particles of gold that are imbedded in them, and their richness is in proportion to the rock in which they are contained as 0.0000065. The richness of auriferous sands not only varies in the different parts of the surface of alluvia, but also with the depth. It is the nature of alluvial deposits to be superficial; that of the particles of gold is to occupy a certain bed in that superficies, sometimes at the surface itself, sometimes at a little distance from that surface. The swiftness of the waters, back-waters, curvatures, obstacles that they may have met with, their greater or less depth, are so many causes of modifications in the sites of auriferous sands; but that which is common to all deposits is not to exceed a certain depth, beyond which there is nothing but sterile sand. As to the richness of such deposits, it does not seem to depend upon position; but that which all experience establishes is, that these deposits are thin and readily exhausted. Gold-diggings have then a term, nor is their duration great. This is one among a number of reasons, all of high importance, why the gold-mining companies, formed to work the deposits in Australia, should not have encumbered themselves with purchases of land-tracts of territory, which, however authentically proved to be auriferous at the time of purchase, cannot, by all experience, be relied upon for productiveness for any great length of time. It has been argued, that a mining company constituted upon the cost-book or any other legitimate principle must have a "mine;" this legal difficulty might be got over by the purchase of the royalty over a very small portion of auriferous alluvia. Where machinery is going to be taken out for crushing, amalgamating, and other metallurgical operations, it will be positively necessary to have a pied à terre; but a small amount of land on the banks of a running stream would suffice for the head-quarters of such mining operations. The adventurers themselves, in carrying out their operations on the alluvia, should be prepared to turn their energies in any direction that science might determine to be the most promising; ready to leave the last deposit when exhausted and unproductive, and to follow up one after another all the advantages of the soil and country. It should be one of the great advantages of such companies to be independent of place, by means of well-arranged commissariat, and that while their capital ensures combined labour and skill, and supplies their wants and necessities, it also secures to the operations a safe foundation upon scientific principles, by placing them under the guidance of competent persons. Taking also all the various points connected with gold-mining into consideration-the facts evidenced by the gold-sands of Africa, the diggings in America and other parts of the world-and which could only be detailed by entering at large upon the geographical portion of the question-the facts evidenced from all antiquity, from the days of the Nile to those of the Pactolus and Tagus, and the facts evidenced by geological and mining experiences,- -we cannot hesitate in giving an unbiassed opinion in favour of the greater chances of those companies which limit their adventure to alluvial diggings, and do not encumber themselves with machinery for rock-mining and quartz-crushing-by all experience, a very uncertain source of profit, while a certain one of expense. As a general fact, the richness of the detritus and alluvium is by no means a certain indication of the richness of the parent rock. Generally speaking, gold-veins are only rich superficially, and it is difficult to say, in alluvia so long lying untouched as those of California and Australia, how long they may have been in accumulating, or how much of the gold may not have been borne away with them-even to the last nugget-from the parent rock. All experience and all science seem to point out to mere digging and washing as the safest means of obtaining gold. The precious metal, indeed, appears to have been sown broadcast on the surface of some lands, as if to invite colonisation. So much for certain suggestive points in the art of practical golddigging, the search for auriferous deposits, or "prospecting," as it is termed in Australia, the nature and character of the alluvia, and the elimination of gold even when invisible to the naked eye. There is, we regret to add, a great fund of thoughtful interest and anxiety in the pictures given by Governor Latrobe, in the "Further Papers," and in the letters of individual correspondents to the newspapers, of the total disorganisation of society that has taken place in Australia, as a result of this sudden and great discovery of auriferous deposits. For some time the impulse given to emigration was by no means such as might have been expected from the nature of these discoveries. The English and Scotch are slow to believe in golden visions. The Irish had not, generally speaking, the means to emigrate. The reality of the vast gold produce becoming, however, definitely known and generally understood, emigration has latterly been carried on on so extensive a scale, that ships trading to all parts of the world have been put upon the Australian line, a new line of screw-steamers has been brought into existence, and the Cunard Company has opened a line of first-class steamers from Liverpool to Australia, viâ Chagres and Panama. At the same time, the attention and the energies of government have been directed to the protection in the colony of the usual branches of industry and more ordinary sources of wealth, to obviating the evils of an increased expenditure and prices of necessaries of life, to the appointment of commissioners, the good order of the population, the granting of licenses, the return of revenue, the establishment of a royal mint, the shipment of gold, the augmentation of salaries, the embarrassments caused by the flow of the population to the gold-diggings, and the effects of the recent discoveries on all branches of the community, and even on the carrying on of government itself. The vast emigration now in progress, new and more decided port regulations to prevent desertion from merchant-vessels, the organisation of an efficient police force, the increase of pay to public officers, and promised military aid from the home government, in the shape of troops of the line, Irish constabulary, and pensioners, will soon remedy many existing evils. According to a statement published in the Melbourne Argus, of March 4th, 1852, the total yield of the Victoria gold-fields up to that period stood as follows: Estimated amount in private hands in the towns 24,000 Estimated amount in the hands of diggers and others on the road and at the mines Or, 54,439lb. 2 oz.-544 cwt. 39lb. 2 oz.-27 tons 4 cwt. 39lb. 2 oz.* Gold conveyed by private hands, and which has not passed at the Customs, is not included in this estimate. Mr. Robert Hunt, in his Lecture on the " History and Statistics of Gold," estimates that the Sydney gold-mines produced, £ S. From 29th May, 1851, to 31st Oct., 1851, 67,152 oz. of gold, value 214,886 0 In the Victoria district, to the end of December, 1851, In December there was shipped from Victoria . 257,855 7 464,668 15 value 75,324 0 96,021 But Mr. Hunt justly remarks, that as only about two-fifths of the gold realised is sent by government escort, there is much difficulty in arriving at the actual amount.† any We We are not among those who entertain any apprehensions from this great influx of gold. The vast increase and diffusion of population, the wear and tear of precious metals, the increased consumption in the useful and ornamental arts, the example of the past, the new countries and populations opened to civilisation and commerce in North and South America, Australia, New Zealand, China, &c., &c., all present circumstances that will more than counterbalance such influx for the present. On the contrary, the supply appears to have come providentially to meet the wants and demands of new and rising generations of men. At the most, even after the lapse of time, and supposing the supply still to be going on, the relations of gold to silver might alone undergo some necessary change; but even that would be put off to an indefinite period, by coining gold moneys of small value, say five shilling and half-crown pieces, or even florins and shillings. The Turks have gold coins of five piastres, or about the value of a shilling. The Chinese, on the contrary, have as yet very little gold currency. Such a coinage in this country would tend materially, by increasing the use and consumption of gold, to keep up the balance of its value as compared with that of silver. Total value sterling, 1,959,810l. According to a still later and apparently authentic statement, the production at the Victoria mines was steadily increasing, and was now estimated at 100,0007. per week, or at the rate of more than 5,000,000l. per annum. |