Benjamin Dearborn’s Respects attend the President, with information that he has brought from Boston a letter addressed to him, accompanied with a pattern for a Cannon-Shot of peculiar construction, devised by Mr. Jacob Welsh, formerly of the U.S. Army, and directed by him to be left with the President.   Mr. D. has also with him some mathematical, and other instruments, of new model, and will be gratified if an opportunity should be presented in the course of the day, to explain their uses to the President of the United States.