Commoder Por ter, eommanding the Misáiss:ppi squadron, in a disp-itch to the tíecrotary of tho Navy, iMaroh 10, says : 'I havo boen pretty well assured for some time past that the Indianola had beeu blown up, ia consequence of the appoarance of a wooden imitation tnortur, which the cneiny sunk with their butteries. Tho mortar was a valuablo aid to us. It foroed away the Quocn of the West and caused tbe blowing up of the Indianola." _ The following is an account of the affair taken from the Viokaburg Whig of the 5tli instant : " We stated a day or two sinee that we eould not enligbten oujp readers ia regard to a matter which was puzzling ;hena very mach. We alluded to the oss of the gunboat Indianola, reeently oaptured from tho enemy. We were oth to aekuowkdge she bad been desroyod, but such is the case. The Yankee barge sent down the river last week was reported to be an iron-chtd gunbcat. The authoritics, thinking that this monster would retake the Iadianola, , ately issued au order to blow lier up. The order was sent down by courier to the officer iu charge of the vessel. A few houi-s afterwards anutlior e-rder was geut down oountermaoding the first, it beiug aseertaiued that the monstrous craft was only a coal boat; but before it reached the Indianols, she had been blown to atoms - not even a gun was saved. Who is to blame for this folly, this precipitaacy ? It would soein as if we liad no use for gunboats on the Mississippi, a3 a ooal burge is maguified into a monster, and our au thorities tmmediatelj order a bout that would have beca worth a sniall army to bo blowc up."