MATHEMATICS, GEOMETRY, TABLES, etc. 1^ 



CoiHjirehoisive Weujht Cahnlator. 



THE WEIGHT CALCULATOR. Being a Series of Tables 

 upon a New and Comprehensive Plan, exhibiting at One Reference the exact 

 Value of any Weight from i lb. to 15 tons, at 300 Progressive Rates, from id. 

 to i6Ss. per cwt., and containing 186,000 Direct Answers, which, with their 

 Combinations, consisting of a single addition (mostly to be performed at 

 sight), will afford an aggregate of 10,266,000 Answers; the whole being calcu- 

 lated and designed to ensure correctness and promote despatch. By Henry 

 Hakben, Accountant, Sheffield, Author of "The Discount Guide." An en- 

 tirely New Edition, carefully revised. Royal Svo, strongly half-bound, ^i 5s. 

 "A iiractical and useful work of reference for men of Inisincss generally: it is tlie best of tlic 



kiiui we have seen. We have frequently been askcil if such a work as tliis could be obtained, and 



therefore refer to it with pleasure." — IroiunoJtf^er. 



"Of priceless value to business men. Its accuracy and coinplGteness have secured for it '^ 



cpntation which renders it quite unnecessary for us to say one. word in its praise. It is a necessary 



book in all mercantile offices." — Sliefficld Indepoidenf. 



" An enormous amount of labour must have been bestowed upon the preparation of the tables. 



but the result is a series which gives the answers sought more readily than any of its predecessors." 



Miiiiii!^ journal. 



Cojupyehenshf Dtsroirnf Guide. 



THE DISCOUNT GUIDE. Comprising several Series of 

 Tables for the use of Merchants, Manufacturers, Ironmongers, and others, 

 by which may be ascertained the exact Profit arising from any mode of using 

 Discounts, either in the Purchase or Sale of Goods, and the method of either 

 Altering a Rate of Discount or Advancing a Price, so as to produce, by one 

 operation, a sum that will realise any required profit after allowing one or 

 more Discounts : to which are added Tables of Profit or Advance from i\ to 

 go per cent.. Tables of Discount from I5 to gSf per cent., and Tables of Com- 

 mission, &c , from ^ to 10 per cent. By Henry Harben, Accountant, Author 

 of "The Weight Calculator." New Edition, carefully Revised and Corrected. 

 Demy Svo, 544 pp. half-bound, £1 5s. 



" .Ml these tables are well arranged and clearly printed ; and the collection will be foi<nd of great 

 ^alue in those businesses for which the book has been especially compiled." — liiij^iiteeriir^'^. 



" A book such as this can only be appreciated by business men, to whotn the saving of time 

 means saving of money. We have the high authority of Professor J. R. Young that the tables 

 throughout the work are constructed upon strictly accurate principles. The work is a model of 

 typographical clearness, and must prove .of great value to merchants, manufacturers, and general 

 traders." — British Trade J-oiirital. 



" Much time and labour will be saved by the use of this book — even to the most expert arith- 

 metician. The great practical utility of the 'Discount Guide' will no doubt make it a standard 

 work of reference." — London Commercial Record. 



Iron and 3Ietal Trades^ Calcnhitor, 



THE IRON AND METAL TRADES' COMPANION. Being 

 a Calculator, containing a Series of Tables upon a New and Comprehensive 

 Plan, for expeditiously ascertaining the Value of any Goods bought or sold 

 by Weight, from is. per cwt. to 112s. per cwt., and from one farthing per 

 pound to one shilling per pound. Each Table extends from one pound to 

 100 tons. To which are appended Rules on Decimals, Square and Cube Root, 

 Mensuration of Superficies and Solids, &c. ; also Tables of Weights of 

 Materials, and other Useful Memoranda. By Thomas Downie. Strongly 

 bound in leather, 396 pp., gs. 



" A most useful set of tables, and will supply a want, for nothing like them before existed." — 

 Sui/din,!^ News. 



" Will save the possessor the trouble of making numerous intricate calculations. Although 

 specially adapted to the iron and metal trades, the tables contained in this handy little companion 

 will be found useful in every other business in which merchandise is bought and sold by weight." — 

 Railway Neics. 



Practical Geometry, 



THE GEOMETRY OF COMPASSES ; or, Problems Resolved 

 by the mere Description of Circles and the use of Coloured Diagrams and 

 Symbols. By Oliver Byrne. Coloured Plates. Crown Svo, 3s. 6d. cloth. 

 " A very useful work, which will be valued by all who are pursuing the useful and fascinating 



study of geometry." — Iron. 



" The treatise is a good one, and remarkable — like all Mr. Byrne's contributions to the science 



of geometry — for the lucid character of its teaching," — Biiildin}^ iXeics. 



' ' The problems in this useful liook are cleverly worked out by beautifully coloured anil uncoloured 



dl.agrams. It will no doubt be extensively circulaterl. We highly reconnnend it," — Caml'Hdji^e 



Jix'frt-ss. 



