ignoring the cough , which was growing worse by the hour , and a new blurriness of vision , which was a real nuisance , i took mojo with me along noisy m street into washington , the capital of the nation proper , wandering about the marble memorials and monuments , the vast and impressive official buildings and residences , and up through the soft sad beauty of arlington cemetery with its thousands of tiny identical headstones , and to the handsome and dusty little mansion of the great confederate general robert e. lee .