bave puzzled both themselves and their readers, is here rendered plain, easy, and intelligible. In Fellowship, several new rules are given. Exchange is likewise treated of in a different manner to what it usually has been, and several useful tables are introduced, which have not hitherto been inserted in books of arithmetic. These tables have, in this edition, been carefully compared with a correct set of tables in the library of Hans Sloane, esq. and likewise with the tables published by the principal writers on exchange, as Kruse, Corbaux, Dubost, &c. Those who wish for farther information on the subject of exchange than is contained in the following treatise, may consult the works above mentioned, or the Universal Cambist, by Dr. Kelly. The nature of Ratios, and Proportions, so far as they relate to coinmensurable quantities is considered. These subjects are of the highest importance. The learned Whiston, in his Tacquet's Euclid, says, “ Si proportionis “ doctrinam e Mathesi abstuleris, nihil fere præclarum “ aut egregium relinques." “ The second part of the work concludes with some general observations on Numbers odd and even; Square and Cube Numbers, &c. These will serve to raise the curiosity of the learner, and give impulse to his farther enquiries. The Bills of Parcels, Promissory Notes, &c., which in the former editions followed Duodecimals, and concluded Part I., are now classed nearly in the same order at the end of the book, forming Part III. In this edition, the Rules for Annuities at Simple Interest have been omitted, being of no use, except as arithmetical exercises, and the principal cases of Annuities on Lives are introduced in lieu of them. All the rules * and examples have undergone a thorough revisal, and many new ones have been added, in consequence of the distinguished approbation which this work has met with from several of the most respectable and intelligent tutors in the kingdom. No. 1, York- Buildings, New Road, St. Mary-le-bone, London, March, 1822. * Algebraical demonstrations of the rules have been purposely omitted ; because to young student who is learning the elements of the Science, they are perfectly unintelligible. The truth of arithmetical operations should be explained, by the teacher, from the nature of the process; for though the theory and practice of Science ought to go hand in hand, yet every experienced teacher will allow, that, in common arithmetic, the practice must in a great measure precede the theory. The young student, who has made himself perfectly master of the practical parts of arithmetic, and has acquired some knowledge of algebra, will derive considerable advantage from the perusal of the Appendix to the Complete Practical Arithmetician, annexed to the Key to that work. This Appendix contains a Synopsis of Logarithmical Arithmetic, together with general demonstrations of all the principal rules in the Complete Practical Arithmetician. CONTENTS, PAGE 91 5 COMPOUND Proportion in do. 85 Multiplication. 8 Questions... 86 Weights and Measures 18 DECIMAL FRACTIONS, ADDITION of Decimals Contracted Division of ditto 94. Definitions ...... ........ 64 SUBTRACTION of ditio ...... 779 Definitions a SUBTRACTION of Circulating Class I. Exchange with MULTIPLICATION of ditto . . 109 certain Price of Exchange 114 for the Pound sterling 183 138 ber of Pence sterling..., 183 139 CLASS III. Places which ex- EQUATION of PAYMENT8.. 148 cent. «............... 184 COMPOUND INTEREST ... 151 Of the Gain or Loss DOUBLE FELLOWSHIP.... 156 the course of Exchange.. 185 160 Arbitration of Exchange.... 193 Definitions 169 To extract the root of any |