The discovery of our Continent by Columbus, rousing, as it did, the nations of the old world to a most extraordinary state of activity, perhap3 produced no more wonderful results than the discovery of gold in the sands of California in 1849. As in the former case, fleet after fleet of adventurous spirits lelt the shores of Europe in search of the El Dorado, so in the latter case, fleet after fleet, with ifo-ring and enterprising men, left our shores,and those also of the old world, in search of the i more modern Gokien Land," on the shores [ of trie Pacific. j An irnp'jiye given is) many Uiiads ill onedi- ivijjii, re-acts upon othtr tnhn?s in a usller- i tilt direction ; thus thorrly aster the discovery of America, the arojc a splendid ;?yn.isty of philosophers. Irorn Gallileo downwards, and an impetus was given to every department of mechanics, which has never flagged lrom that day to this. In our own times, also, those who have watched the course of events— readers of the signs tt the times—have not Jailed to perceive the wonderful vaultings, w it were, of mind in invention and discovery since the golden nuggets of California and Australia began to lure forth so many thousands from their old homes and habits, to new scenes and new occupations. To meet new commercial wants, a complete revolution is being effected in naval architecture,- and to meet the wants of the toilers amid the gulches and ravines of the golden country, thousands have directed their attention to invent new machinery whereby the K noble metal " might be rapidly and economically separated from its earthy companionship. No one living out of New York City can form a proper idea respecting the number and variety of machines which have been exhibited in our streets to the thousands who have come here from different parts of trur country on their way to California. We hav t?ken no public notice of the great mass of these machines, because they did not appear to be worthy of criticism or commendation. Hundreds of such machines, as told to us, have been sold to credulous gold-seekers, only to be thrown away or trampled under foot when they arrived at their destination. Some machines, possessing much originality and merit, we have illustrated and spoken of as they deserved, such as Cochrane's excellent Planetary Crusher, Gardiner's Magnetic Extractor, Buffum's Centrifugal Separator, and Berdan's Inclined Grinder and Amalgamator, which was represented on page 65, this Volume. After eight years of experience in such matters, as public journalists, our readers know full well that we are somewhat cautious, and not over-prolific of praise, even in the most deserving cases, while on the other hand, we are not very fastidious nor backward in speaking freely of miserable and deceptive schemes, when convinced that we owe it as a duty to the public to do so. Within the past two years more attention has been devoted to the invention of good crushers and amalgamators than to mere gold washing machines, and the reason is obvious. The aiiiiferous sands of California and other golden lands, will soon cease to yield their treasures, but not so the golden quartz rocks. With proper machinery they will produce for centuries to come unlimited quantitiesof gold. The business of obtaining gold from such sources, will, in a few years, be in the hands of those who have capital, to purchase and use improved machinery, and those who use the best will certainly make the largest profits. Since we published the illustrated description of the last-named machine (Berdan's), andes-pecially since we noticed one of its public exhibitions on page 258, we have paid further attention to its workings and have closely investigated the principle of its action, and we have no hesitation in pronouncing it without a superior as a quartz crusher and as an amalgamator (it combines both qualities), it is the best we have seen. It amalgamates so per-lectly that different chemists, by a careful analysis of the tailings or refuse, have failed to detect the slightest particle of gold. This certainly is a very emphatic recommendation of the qualities of this machine. We visited the Novelty Works last week and saw a large number of workmen busily employed in constructing these machines for California, North Carolina, and other gold mining districts, and we understand that more than two hundred have been made and disposed of already. The reason why it operates so rapidly and perfectly is owing to the nature of its action and operation; which need not now be described, as we fully illustrated the machine on page 65 of the present volume ; suffice it to sayj that new surfaces of gold and mercury are continually brought into contact by the ball and basin moving in contrary directions. I Having been informed that there are some j large companies now forming in England for i working the gold quartz of Australia, and ha-I ying seen in the " London Mining Journal " ! an account of one company in London, which S had expended a great amount of money on machinery to work the gold quartz of California, from which they had never received, in return, a single dollar, although men and machinery were sent to San Francisco more than two years ago,—we deern it our duty, at this time, to direct the attention of our transatlantic brethren to the merits of this superior American machine. We also do so, especially, as a matter of duty to our readers in Britain—having not a few in that country; we speak to them in confidence of what we have seen for ourselves.