new Bengal Standard Beegah-Khusrah and Thak- VI. ON THE ORTHOGRAPHY OF NATIVE NAMES, GENERAL STATISTICS, GEO- Sir Wm. Jones' method for the conversion of the Of the fixed Stars-Northern and Southern Constella- tions-Directions for finding the Constellations in II. ON THE DETERMINATION OF THE ERROR of a ChronOMETER; AND OF THE AZI- MUTH OF THE REFERRING MARK FROM on the 24-Pergunnah Survey as compared with the III. ON THE DETERMINATION OF THE ERROR AND RATE OF A CHRONOMETER, UPON Mode of proceeding by the Sun on mean time-Exam- ple and Computation-Mode of proceeding by a Star on mean time-Example and Computation-To find the error and rate of a Chronometer upon the Sidereal time-Example and Computation- IV. ON THE DETERMINATION OF THE ERROR To determine time when the high Star is observed V. ON THE CONVERSION OF A GIVEN CHRONO- Examples and Computation of the Conversion of the given Chronometer time to mean Solar time, Siderial and vice versâ-Method of computing the Chronome- ter time corresponding to a given mean Solar or VI. ON THE METHOD OF DETERMINING THE FROM AN OBSERVATION TAKEN TO A CIRCUMPOLAR STAR, AT THE TIME OF Elements required-Formula for Computation-Type ON THE METHOD OF DETERMINING THE AZIMUTH OF THE REFERRING MARK, FROM OBSERVATIONS TAKEN TO A CIR- CUMPOLAR STAR NEAR THE TIME OF ITS MAXIMUM ELONGATION, AS PRACTISED IN THE Great Trigonometrical Sur- VEY OF INDIA, ALSO ON THE MODE OF FINDING THE VARIATION OF THE NEEDLE. 687 Col. Everest's Method of taking a Circumpolar Star- Specimen of the Angle Book for registering Circum- polar Star observations-Computation—Variation of Method of determining the Latitude by the Meridional Altitude of the Sun-Example and Computation- Formula for computing the correction to be applied for observations taken before and after the apparent noon-Illustration of the Computation of these For- mulo-Method of determining the Latitude by an observation on the Pole Star-By taking the eleva- tions of a circumpolar Star at its upper and lower TABLE. Definition of Longitude-Reasons for reckoning Longitude in time-Observations for the absolute Longitude of Station-Process of determining the difference of Longitude between two places by a Chronometer-Ditto by a route Survey. A. For correcting Gunter's Chains of 100 Links or 66 Feet. B. For reducing Chains to the Decimal Parts of a Mile. TABLE. D. For Converting Chains and Links into Feet and Decimals Page. vii H. Comparative Scale of Fahrenheit's, Reaumur's and the ...... I. For Converting Intervals of Sidereal Time into Equiva- J. For Converting Intervals of Mean Solar Time into Equi- ... K. Showing the correction to be applied to a Barometer with a Brass Scale, extending from the Cistern to the Top of the Mercurial Column, to reduce the observation to 32° Fahrenheit. xi xii xiv xvi xviii M. For converting Beegahs of 80 Haths or 1600 Square Yards into Corresponding Acres. N. For converting the Decimal part of an Acre or Bengal Beegah into its corresponding value of Roods and Poles or Cottahs and Chittacks. O. Of Square Measure for Bengal Standard Beegah of 14400. P. For Converting Acres into Beegahs of 3025 Square Yards. xxiv R. For Converting Beegahs of 3025 Square Yards into Acres. XXV EXPLANATION AND USE OF THE TABLES. xxvi Desiderata for the Museum of Economic Geology of India. xxxiii LATITUDES and LONGITUDES of the principal places in A MANUAL OF SURVEYING FOR INDIA. Part L. GEOMETRY. CHAPTER I. NECESSARY DEFINITIONS AND FIRST PRINCIPLES. GEOMETRY is the science that treats of the properties of magnitude in general. The subjects which it considers are extent of distance, extent of surface, and extent of capacity or solid content. It is the foundation of Mensuration, Surveying and other practical branches: it embraces the measurement equally of the earth and the heavens; it forms with arithmetic the basis of all accurate conclusions in the mixed sciences, and there is scarcely aný mechanical art, our views of which may not be improved by an acquaintance with it. The truths of Geometry are founded on definitions, each furnishing at once an exact notion of the thing defined, and the groundwork of all conclusions relating to it. The leading definitions are as follows: A point is that which has position but not magnitude. B |