The great demand for the first volume of the steel square and its uses convinced the writer that a second volume on the same subject would be sure to meet with a fair reception. The I readers of Vol. I. Will want to see and know more of what may be done by the aid of the Steel Square and a little mental effort. The present volume, like the first, contains but little of bewildering mathematics, and is brought down as near to the operative workman's standard as possible.