Th: Jefferson returns his thanks to Doctr. Mitchell for the Statistical Manual of New York, and is pleased with every evidence of the growth & prosperity of so important a city.   The Secretary at war would have set out this day, but for the rain now falling, to meet the Vicepresident & Colo. Williams there, to consider what works can be of any avail towards protecting that city from naval enterprizes. Th:J. salutes Dr. Mitchell with friendship & respect.