periments wore made at the Navy Yard on Friday, and the effects of the Dablgren gun upon iron-clad targets, compkitely vindicatü the opinión expressed by Cnputin D;ihlgren in his recent report to ihe Secretary of the Kavy upon the subiect of destroying ironclads. A target oí Captain Ericeson's, made up entirely of wrouglit iron to the thickness of fifteen inches, was? tusted at the yard. It was fired at by an eleven inch Dahlgren gun about fifty feet distance. The gun was loaded with thirty pounda ol powder and solid shot. The peoetration waa quite ineonsidorable, but the eonatruction of tlie target was completelv díelocated by the blow. Only two of the ihrough bolts were unbroken. All the bolts in the vicinity oí tlio blow were separatbd and muoh bent. The target itself though weighing severa! tons', waa driven back several inches, and the blow also displaced the heavy masonry against which it had been braced.