Since our last notice of this building, the constructors have made some progress, but they must keep their fingers hot if they get it all ready as they have promised by the 1st of May next. The weather during the past two weeks has not been very favorable, and we shall have many stormy days before " moving day," there is therefore a marked necessity for hurrying up the pillars. We understand that those who took contracts for the castings have not been made rich by them, owing to the low prices, and the rise in the price of metal. The California papers say that a pure diamond of seventeen carats has been found near Sonora.