Elementary Treatise on the Calculus for Engineering Students. By J. Graham. Fourth edition, 116 illus., xii + 355 pp., cr. 8vo. (1914.) 5s. net.

Manual of the Slide Rule. By F. A. Halsey. Second edition, 31 illus., 84 pp., 18mo, boards. (New York, 1901.) 2s. net.

Reform in Chemical and Physical Calculations. By C. J. T. Hanssen. 4to. (1897.) 6s. 6d. net.

Algebra Self-Taught. By P. Higgs. Third edition, 104 pp., crown 8vo. (1903.) 2s. 6d.

A Text-book on Graphic Statics. By C. W. Malcolm. 155 illus., 316 pp., 8vo. (New York, 1909.) 12s. 6d. net.

Galvanic Circuit Investigated Mathematically. By G. S. Ohm. Translated by William Francis. 269 pp., 18mo, boards. (New York, 1891.) 2s. net.

Elementary Practical Mathematics. By M. T. Ormsby. Second edition, 128 illus., xii + 410 pp., medium 8vo. (1911.) 5s. net.

Elements of Graphic Statics. By K. Von Ott. Translated by G. S. Clarke. 95 illus., 128 pp., crown 8vo. (1901.) 5s.

Figure of the Earth. By F. C. Roberts. 2 illus., 95 pp., 18mo, boards. (New York, 1885.) 2s. net.

Arithmetic of Electricity. By T. O'C. Sloane. Thirteenth edition, 5 illus., 162 pp., crown 8vo. (New York, 1901.) 4s. 6d. net.