The " Evening Post" will confer a favor upon an anxious people by letting them know how its Ericsson engine works—how it makes the presses fly, how much fuel it saves, and any other item of interest connected with it. It is now two months since the engine prepared tor the Post, was to be sent to France, and another was to be constructed at once. The said engine could certainly be duplicated in one month, consequently, we infer the " Post's " engine must be in operation.