half minute. It is seldom necessary in practical questions of this kind to proportion to the nearest second; and in nautical problems the above degree of accuracy will in almost every case be sufficient. JANUARY 1, 1842. CONTENTS. (n) To find index of logarithm of any number (n) To find the logarithm of any number ..18-19 (n) To find the value of number with fractional index Examples to preceding rules (n) Of four proportional quantities, any three being given to find the fourth, by logarithms (n) To reduce algebraical formulæ to logarithms (0) Application of logarithms to problems in geo- metrical progression. &c. (n) To take quantities out of logarithmic tables (n) When the given angle is greater than 90° (n) To take quantities out of table of natural versines VIII CONTENTS. Rules in Plane Trigonometry. PAGE Three sides of a plane triangle being given to find an angle (using table of haversines) Three sides of a plane triangle being given to find an angle, (without using haversines) (n) V. (n) (n) VI. Two sides and included angle being given, to (n) VIII. Three sides of a spherical triangle being given to find an angle. (using haversines) Three sides of a spherical triangle being given to find an angle (not using haversines). Two sides and included angle being given to find the third side (using haversines). Two sides and included angle being given to find the third side (not using haversines) Rules for right angled spherical triangles The articles marked (0) may be omitted at first by the Student. |
