We Bhall advert to the construction of rail ways, in which we have had some little experience in Auckland, and made such astonishingly slow progress. To give some thing like an idea of the magnitude of the works in progress, we will compile a few details from our latest American exchanges. The President, in his annual message, thus refers to the Pacific railroads : — Operations on the several lines of the Pacifio Railroad have been prosecuted with unexampled vigour and success. Should no unforeseen causes of delay occur, it is confidently anticipated that this great thoroughfare will be completed before tha expiration of the period designated by Congress. The San Francisco Hfoening Bulletin gives something like a comprehensive notion of how these works are progressing, as well as details of several'minor projects of the same kind presently on foot in California. "We quote from that paper of the 27th November, 1866 : — SOUTHERN PACIFIC RAILROAD. - California seems to be on the ere of great activity in railroad operations. The facility with which railroads can be built with Government aid, the prospectively great profits of roada thus aided, and the stimulus of lopal rivalry for connection with tide water and a share of the transmontane trade, are the principal causes which have quickened enterprise in this direction. Then there is a confident and well grounded expectation among sagacious men, that with the completion of the Pacifio railroad, and the diversion of Oriental commeroe and- 1 exchange to the direct land route between the Pacific and the At lantic, an era of remarkable prosperity will begin for this State, when the {conditions will be mutually favourable to certain leading lines of railroad. We bare described the condition and prospects of the Central Pacific Bailroad, of the California and Ore gon Railroad, of the Western Pacific, which is to connect thqse both by way of Stockton and San Jose with San Francisco, and of the Yallejo and Marjs ville Road, whioh is to furnish the most direct com munication between San Francisco, Sacramento, and "Northern California.; These roftds»:with the spur lines known as the Alamed*, the Napa, the Lincoln and Marysville, tbeOroville, and perhaps the Benicia , and Sacramento roads, form a grand system for con necting all parts of Northern and Central California with the metropolis, and with the central highway across the .continent. 