In some parts of the country, where neither granite nor sandstone is easily procured, blue and gray limestone are sometimes used for building, and, when hammer dressed, often look like granite. A serious objection to their use, however, is the occasional presence of iron, which rusts on exposure, and defaces the building. In Western New York they are widely used. Topeka stone, like the coquine of Florida and Bermuda, is soft like wood when first quarried, and easily wrought, but it hardens on exposure. The limestones of Canton, Mo., Joliet and Athens, Ill., Dayton, Sandusky, Marblehead, and other points in Ohio, Ellittsville, Ind., and Louisville and Bowling Green, Ky., are great favorites west. In many of these regions limestone is extensively used for macadamizing roads, for which it is excellently adapted. It also yields excellent slabs or flags for sidewalks. One of the principal uses of this variety of stone is its conversion, by burning, into lime for building purposes. All limestones are by no means equally excellent in this regard. Thomaston lime, burned with Pennsylvania coal, near the Penobscot River, has had a wide reputation for nearly half a century. It has been shipped thence to all points along the Atlantic coast, invading Virginia as far as Lynchburg, and going even to New Orleans, Smithfield, R.I., and Westchester County, N.Y., near the lower end of the Highlands, also make a particularly excellent quality of lime. Kingston, in Ulster County, makes an inferior sort for agricultural purposes. The Ohio and other western stones yield a poor lime, and that section is almost entirely dependent on the east for supplies.