By the Washington papers we learn that Prof. Porter has been astonishing the dwellers in that goodly city with his wonderful Aero-port, 20 leet long, and filled with hydrogen gas—the lightest of all the known elements ot matter. " The float was filled with hydrogen gas ; from it was suspended a saloon, containing a steam engine to move the screw propellers, which operate between the float and the saloon. The A roport moved gracefully around the room to the great delight of the spectators. So far as this experiment is concerned it was successful." We are not informed of the size of the steam engine ; it was no doubt as big as a piece of chalk, therefore, according to the small amount of evidence, which is required by so many paragraphists, we have now a demonstrated fact ot aerial steam navigation being perfectly successful. We have no such hope, because we have no faith in this project,—some new discovery must be made before that can be accomplished. Prof. P., however, is a wonderful wizard in conjuring up new inventions to contend for victory with the " Prince of the Power of the Air." A Boston firm has just cut 5,000 tons of ice on Winnipissiogee Lake. Its cost will be $2 per ton at Long Wharf, the firm will get at least 525,000. .