32. MATHEMATICAL INSTRUMENTS, a Treatise on; in which their Construction and the Methods of Testing, Adjusting, and Using them are concisely Explained. By J. F. Heather, M.A., of the Royal Military Academy, Woolwich. Original Edition, in 1 vol., Illustrated, is. 6d. *** In ordering the above, be careful to say, " Original Edition " (No. 32), to distinguish it from the Enlarged Edition in 3 vols. (Nos. 168-9-70.)

60. LAND AND ENGINEERING SURVEYING, a Treatise on; with all the Modern Improvements. Arranged for the Use of Schools and Private Students ; also for Practical Land Surveyors and Engineers. By T. Baker, C.E. New Edition, revised by Edward Nugent, C.E. Illustrated with Plates and Diagrams. 2s.t

61*. READY RECKONER FOR THE ADMEASUREMENT 0F LAND. By Abraham Arman, Schoolmaster, Thurleigh, Beds. To which is added a Table, showing the Price of Work, from 2s. 6d. to 1 per acre, and Tables for the Valuation of Land, from Is. to 1,000 per acre, and from one pole to two thousand acres in extent, etc, etc. Is. 6d.

76. DESCRIPTIVE GEOMETR Y, an Elementary Treatise on; with a Theory of Shadows and of Perspective, extracted from the French of G. Monge. To which is added, a description of the Principles and Practice of Isometrical Projection ; the whole being intended as an introduction to the Application of Descriptive Geometry to various branches of the Arts. By J. F. Heather, M.A. Illustrated with 14 Plates. 2s.

178. PRACTICAL PLANE GEOMETRY: giving the Simplest

Modes of Constructing Figures contained in one Plane and Geometrical Construction of the Ground. By J. F. Heather, M.A. With 215 Woodcuts. 2s.

179. PROfECTION: Orthographic, Topographic, and Perspective: giving the various Modes of Delineating Solid Forms by Constructions on a Single Plane Surface. By J. F. Heather, M.A. [In preparation.

*** The above three volumes will form a Complete Elementary Course of

Mathematical Drawing.

83. COMMERCIAL BOOK-KEEPING. With Commercial Phrases and Forms in English, French, Italian, and German. By James Haddon, M.A., Arithmetical Master of King's College School, London, Is. 6d.

84. ARITHMETIC, a Rudimentary Treatise on: with full Explanations of its Theoretical Principles, and numerous Examples for Practice. For the Use of Schools and for Self-Instruction. By J. R. Young, late Professor of Mathematics in Belfast College. New Edition, with Index, Is. 6d.

84*. A Key to the above, containing Solutions in full to the Exercises, together with Comments, Explanations, and Improved Processes, for the Use of Teachers and Unassisted Learners. By J. R. Young, is. 6d.

85. EQUA TIONAL ARITHMETIC, applied to Questions of Interest, gc*. Annuities, Life Assurance, and General Commerce ; with various Tables by which all Calculations may be greatly faeilitated. By W. Hipsley. 2s.

86. ALGEBRA, the Elements of. By James Haddon, M.A.,

Second Mathematical Master of King's College School. With Appendix, containing miscellaneous Investigations, and a Collection of Problems in various parts of Algebra. - 2s. 85*. A Key and Companion to the above Book, forming an extensive repository of Solved Examples and Problems in Illustration of the various Expedients necessary in Algebraical Operations. Especially adapted for Self-Instruction. By J. R.Young, is. 6d. 88. EUCLID, The Elements of : with many additional Propositions 8q and Explanatory Notes: to which is prefixed, an Introductory Essay on Logic. By Henry Law, C.E. 2s. 6d #

*** Sold also separately, viz. :- 1

88. Euclid, The First Three Books. By Henry Law, C.E. Is. 6d,

89. Euclid, Books 4, 5, 6, 11, 12. By Henry Law, C.E. Is. 6d,

The # indicates that these vols, may be had strongly bonnd at 6d. extra.

LONDON: CROSBY LOCKWOOD AND CO.,

90. ANALYTICAL GEOMETRY AND CONIC SECTIONS, a Rudimentary Treatise on. By James Hann, late Mathematical Master of King's College School, London. A New Edition, re-written and enlarged by J. R. Young, formerly Professor of Mathematics at Belfast College. 2s.#

91. PLANE TRIGONOMETRY, the Elements of. By James

Hann, formerly Mathematical Master of King's College, London, Is. 6d.

92. SPHERICAL TRIGONOMETRY, the Elements of. By James

Hann. Revised by Charles H. Dowling, C.E. is. *** Or with " The Elements of Plane Trigonometry" in One Volume, 2s. 6d.

93. MENSURATION AND MEASURING, for Students and Practical Use. With the Mensuration and Levelling of Land for the Purposes of Modern Engineering. By T. Baker, C.E. New Edition, with Corrections and Additions by E. Nugent, C.E. Illustrated, Is. 6d.

102. INTEGRAL CALCULUS, Rudimentary Treatise on the. By

Homersham Cox, BA. Illustrated, Is.

103. INTEGRAL CALCULUS, Examples on the. By James Hann, late of King's College, London. Illustrated, Is. ior. DIFFERENTIAL CALCULUS, Elements of the. By W. S. B. Woolhousk, F.R.A.S., etc. is. 6d.

105. MNEMONICAL LESSONS. - Geometry, Algebra, and

Trigonometry, in Easy Mnemonical Lessons. By the Rev. Thomas Penyngton KirkmAn, M.A. is. 6d.

J36. ARITHMETIC, Rudimentary, for the Use of Schools and Self-Instruction. By James Haddon, M.A. Revised by Abraham Arman. is. 6d.

137. A Key to Haddon's Rudimentary Arithmetic. By A. Arman. is. 6d.

168. DRAWING AND MEASURING INSTRUMENTS. Including - I. Instruments employed in Geometrical and Mechanical Drawing, and in the Construction, Copying, and Measurement of Maps and Plans. II. Instruments used for the purposes of Accurate Measurement, and for Arithmetical Computations. By J. F. Heather, M.A., late of the Royal Military Academy, Woolwich, Author of " Descriptive Geometry," etc, etc. Illustrated, Is. 6d.

169. OPTICAL INSTRUMENTS. Including (more especially) Telescopes, Microscopes, and Apparatus for producing copies of Maps and Plans by Photography. By J. F. Heather, M.A. Illustrated, Is. 6d.

170. SURVEYING AND ASTRONOMICAL INSTRUMENTS.

Including - I. Instruments Used for Determining the Geometrical Features of a portion of Ground. II. Instruments Employed in Astronomical Observations. By J. F. Heather, M.A. Illustrated, Is. 6d. „* The above three volumes form an enlargement of the Author's original work, " MathematicalInstruments: their Construction, Adjustment, Testing, and Use, the Thirteenth Edition of which is on sale, price Is. 6d. (See No. 32 in the Series.)

168. MATHEMATICAL INSTRUMENTS. By J. F. Heather,

169. MA. Enlarged Edition, for the most part entirely re-written. The 3 Parts as 170..) above, in One thick Volume. With numerous Illustrations. 4s. 6d.t

158. THE SLIDE RULE, AND HOW TO USE IT; containing full, easy, and simple Instructions to perform all Business Calculations with unexampled rapidity and accuracy. By Charles Hoare, C.E. With a Slide Rule in tuck of cover. 2s. 6d.#

185. THE COMPLETE MEASURER ; setting forth the Measure-ment of Boards, Glass, etc, etc.; Unequal-sided, Square-sided, Octagonal-sided, Round Timber and Stone, and Standing Timber. With a Table showing the solidity of hewn or eight-sided timber, or of any octagonal-sided column. Compiled for Timber-growers, Merchants, and Surveyors, Stonemasons, Architects, and others. By Richard Horton. Fourth Edition, with valuable additions. 4s.; strongly bound in leather, 5s.

196. THEORY OF COMPOUND INTEREST AND ANNUL TIES; with Tables of Logarithms for the more Difficult Computations of Interest, Discount, Annuities, etc. By Fe"dor Thoman. 4s.#

The % indicates that these vols, may be had strongly bound at 6d. extra.

7, STATIONERS' HALL COURT, LUDGATE HILL. E.G.

199. INTUITIVE CALCULATIONS; or, Easy and Compendious

Methods of Performing the various Arithmetical Operations required in Commercial and Business Transactions ; together with Full Explanations of Decimals and Duodecimals, several Useful Tables, etc. By Daniel O'Gorman. Twenty-fifth Edition, corrected and enlarged by J. R. Young, formerly Professor of Mathematics in Belfast College. 3s.#:

204. MATHEMATICAL TABLES, for Trigonometrical, Astronomical, and Nautical Calculations ; to which is prefixed a Treatise on Logarithms. By Henry Law, C.E. Together with a Series of Tables for Navigation and Nautical Astronomy. By J. R. Young, formerly Professor of Mathematics in Belfast College. New Edition. 3s. 6d.±

221. MEASURES, WEIGHTS, AND MONEYS OF ALL NATIONS, and an Analysis of the Christian, Hebrew, and Mahometan Calendars. By W. S. B. Woolhouse, F.R.A.S., F.S.S. Sixth Edition, carefully revised and enlarged. 2s #

227. MATHEMATICS AS APPLIED TO THE CONSTRUC-

T1VE ARTS. Illustrating the various processes of Mathematical Investigation, by means of Arithmetical and Simple Algebraical Equations and Practical Examples; also the Methods of Analysing Principles and Deducing Rules and Formulae, applicable to the Requirements of Practice. By Francis Campin, C.E., Author of "Materials and Construction," etc. Second Edition, revised and enlarged by the Author. 3s. # [Just published.