TABLE OF CONTENTS. IX 



HYGROMETRICAL th.m.U^.— Continued. 



Table ^^ok 



Reduction of psychrometric observations — Metric measures. 



43 Pressure of" aqueous vapor 142 



44 Values of 0.000660 ^(i'—/,) (^ I r ^^^') i43 



45 Relative humidity — Temperature Centigrade 144 



Reduction of snowfall measurements. 



46 Depth of water corresponding to the weight of snow (or rain) 



collected in an 8-inch gage 146 



47 Rate of decrease of vapor pressure with altitude 146 



WIND TABLES. 



Mean direction of the wind by Lambert's formula — 



48 Multiples of cos 45° ; form and example of computation . . 148 



49 Values of the mean direction (a) or its complement (90 — a) 149 



50 Synoptic conversion of velocities 154 



51 Miles per hour into feet per second 155 



52 Feet per second into miles per hour i55 



53 Metres per second into miles per hour 156 



54 Miles per hour into metres per second 157 



55 Metres per second into kilometres per hour 158 



56 Kilometres per hour into metres per second , • i59 



57 Beaufort wind scale and its conversion into velocity 160 



GEODETICAL TABLES. 



58 Relative acceleration of gravity at different latitudes .... 162 



59 Length of one degree of the meridian at different latitudes . . 164 



60 Length of one degree of the parallel at different latitudes . . 165 



61 Duration of sunshine at different latitudes 166 



62 Declination of the sun for the year 1894 i77 



63 Relative intensity of solar radiation at different latitudes . . . 178 



CONVERSION OF LINEAR MEASURES. 



64 Inches into millimetres i^o 



65 Millimetres into inches 187 



66 Feet into metres . . " 200 



67 Metres into feet 202 



68 Miles into kilometres 204 



69 Kilometres into miles 206 



70 Interconversion of nautical and statute miles ....... 208 



71 Continental measures of length with their metric and English 



equivalents 208 



