The second Industrial Exhibition of the above Institute will be held on the first of September next, and will continue open for fifteen days. The State Horticultural Society will also hold its second annual exhibition in conjunction with the Institute, and thus the California mechanic and agriculturist—twin brothers in the useful arts—will stand, as they always should, on the same platform. The San Francisco Mechanics' Institute is a spirited and flourishing association, and we think it will do a great and noble work for California, as the prosperity of any State depends chiefly on the character and number of its mechanics. They fabricate the engines, machines, and implements by which agriculture, commerce, and all the useful arts are conducted and carried on. " By hammer and hand All trades do stand." Prosperity always attends a nation in which the mechanic arts flourish. Wherever the mechanics are in a low condition, the mass of the people sink to the same level; a general poverty, at least, is always the consequence. Turn our eyes to whatever quarter of the world we may, and these assertions will be fully borne out by the condition of the various peoples inhabiting our globe. Those, therefore, who are engaged in the mechanics' institutes and other kindred societies, are doing a noble work for their country and fellow men in their endeavors to raise the dignity of their callings, and to render the mechanic arts respectable and flourishing. At the exhibition of the above institution held last year, the secretary, Mr. H. F. Williams, delivered an able address, from, which we glean some instructive statistics in reference to the progress of California, a few of which we shall present :— In 1850, the entire area of land under cultivation in California was only 5,000 acres; in 1856 it had increased to 500,000; 17,000 bushels of wheat were raised in 1850—in 1856, 4,000,000. In the latter year 2,000,000 gallons of native wines were made, and other agricultural products were raised in equal proportions. California is fast becoming a great agricultural State, and now exports wheat. In 1850, there were only 25 mills in the Golden State; in 1856 there were 500, exclusive of the quartz mills. There are now over 130 grist and 370 saw mills. The flour mills can turn out 2,000,000 barrels annually, and the saw mills 500,000,000 feet of lumber in the same time. Both flour and lumber were exported last year to the value of $1,000,000. There are 14 foundries, and a large number of machine shops in San Francisco in success-, ful operation; and engines, boilers, quartz machines, and almost all other kinds of machinery are now manufactured extensively. A considerable quantity of furniture is also made from the native woods, some of which are very beautiful, and eminently adapted for cabinet work. A sugar refinery and soap factory have been erected; but although ' $4,000,000 worth of hides are annually ex-1 ported from thence, no tannery has yet been ? put in operation; and yet $20,000,000 are : yearly paid for imported boots and shoes. The early history of California is filled with ' scenes of debauchery and crime. The ma-i jority of the early adventurers went there f solely to make money in any way, not to make that land their home. Some of the ' noble spirits who then went out, and who, in ' the exhibition of high moral principles, re- fused to gamble and carouse, and were scouted i and sneered at, are now all the more highly lonored because of their moral steadfastness amid so many temptations. Of late years, a rery respectable class of yeomen and mechanics' families have gone thither, to make it their future abode. The valleys of the golden land are now beginning to smile with peace and plenty; the church and the school-house —those necessary adjuncts of morality and civilization^are to be seen in every village. California is, perhaps, yet destined to be the greatest State of the Republic.