Vlll TABLE OF CONTENTS. 



Table - Page 



23 Decimals of a day into hours, minutes and seconds .... 56 



24 Minutes and seconds into decimals of an hour ...'... 57 



25 Local mean time at apparent noon 57 



26 Sidereal time into mean solar time 58 



27 Mean solar time into sidereal time 58 



CONVERSION OF MEASURES OF WEIGHT. 



28 Conversion of avoirdupois pounds and ounces into kilograms . 60 



29 Conversion of kilograms into avoirdupois pounds and ounces . 61 



30 Conversion of grains into grams 61 



31 Conversion of grams into grains 62 



WIND TABLES. 



32 Synoptic conversion of velocities 64 



33 Miles per hour into feet per second 65 



34 Feet per second into miles per hour 65 



35 Meters per second into miles per hour 66 



36 Miles per hour into meters per second 67 



37 Meters per second into kilometers per hour 68 



38 Kilometers per hour into meters per second 69 



39 Scale of velocity equivalents of the so-called Beaufort scale of 



wind 70 



Mean direction of wind by Lambert's formula — 



40 Multiples of cos 45 ; form and example of computation . . 71 



41 "Values of the mean direction (a) or its complement (90 —a) 72 

 Radius of critical curvature and velocities of gradient winds 



for frictionless motion in highs and lows — 



42 English measures 77 



43 Metric measures 78 



REDUCTION OF TEMPERATURE TO SEA LEVEL. 



44 English measures 82 



45 Metric measures . 83 



BAROMETRICAL TABLES. 



Reduction of mercurial barometer to standard temperature — 



46 English measures 86 



47 Metric measures 106 



Reduction of mercurial barometer to standard gravity — 



48 Direct reduction from local to standard gravity .... 129 

 Reduction through variation with latitude — 



49 English measures 130 



50 Metric measures 132 



