Symbols and the Signs of Operation -- The Equation and the Unknown Quantity -- Positive and Negative Quantities -- Multiplication -- Involution -- Exponents -- Negative Exponents -- Roots, and the Use of Exponents as Logarithms -- Logarithms -- Tables of Logarithms and Proportionate Parts -- Transformation of System of Logarithms -- Common Uses of Common Logarithms -- Compound Multiplication and the Binomial Theorem -- Division, Fractions, and Ratio -- Continued Proportion -- The Series and the Summation of the Series -- Limit of Series -- Square and Cube Roots -- Equations -- List of Formulæ, etc. JUST PUBLISHED. In super-royal 8vo, 1168 pp., _with 2400 illustrations_, in 3 Divisions, cloth, price 13_s._ 6_d._ each; or 1 vol., cloth, 2_l._; or half-morocco, 2_l._ 8_s._ A SUPPLEMENT TO SPONS’ DICTIONARY OF ENGINEERING, Civil, Mechanical, Military, and Naval. EDITED BY ERNEST SPON, MEMB. SOC. ENGINEERS. The success which has attended the publication of ‘SPONS’ DICTIONARY OF ENGINEERING’ has encouraged the Publishers to use every effort tending to keep the work up to the standard of existing professional knowledge. As the Book has now been some years before the public without addition or revision, there are many subjects of importance which, of necessity, are either not included in its pages, or have been treated somewhat less fully than their present importance demands. With the object, therefore, of remedying these omissions, this Supplement is now being issued. Each subject in it is treated in a thoroughly comprehensive way; but, of course, without repeating the information already included in the body of the work. The new matter comprises articles upon