Washington June 19. 08.
Your favor of the 4th. was recieved on my return to this place, and the proposition of your correspondent on the subject of fortification was referred to the Secretary at War, whose office & qualifications make him the proper judge of it. I inclose you his answer. the same prudence which in private life would forbid our paying our own money for unexplained projects, forbids it in the dispensation of the public monies. it is not enough that an individual, & an unknown one says & even thinks he has made a discovery of the magnitude announced on this occasion. not only explanations, but the actual experiment must be required before we can cease to doubt whether the inventor is not decieved by some false or imperfect view of his subject. still your patriotic attention to bring such a proposition under our notice, that it might be applied to the public good, if susceptible of it, is praiseworthy, and I return you thanks for it with the assurances of my esteem & respect
DLC: Papers of Thomas Jefferson.