90 



Paragraph 



Fortin barometers, Weather Bureau pattern 7 



Glycerine barometer 61 



Gravity, influence of, on barometric observations, tables 197 



reduction to standard 102, 197 



altitude term 174 



latitude term 174 



Green barometer 7 



Heights determined by aneroids 105, 107 



barometric readings 104, 107 



tables for, determination of, by barometer 199 



Holosteric barometer 6 



Howson's barometer 65 



Impure mercury not to be used 138 



Index point of barometer 9 



Ink for barograph pens 159 



Instruction for cleaning barometers 123-144 



Interpolation explained 196 



Interval between comparative readings on removal of barometers 148, 166 



Inverting barometers at elevated station 114 



Ivory point, difficulty of cleaning around 134 



of barometer 10 



position not to be changed in cleaning barometer 128, 136 



Leaks in cistern of barometer 141 



Leaky barometer, how to open cistern of 126 



Leather carrying cases 146 



Line of levels, how run 165 



need not be run 167 



must be run 162 



Location of barometers changed 148 



Magnifying barometers, comments on 67 



Marine barometer 26-31 



Marvin's normal barograph 71 



Mercury, how filtered 139 



how purified 138 



impure, disposed of 189 



not to be removed 190 



purity of, indicated 139 



tested 137 



requisition for 188 



"Metallic click" in barometer tubes 111, 113 



Moving and packing barometer 109, 145 



Nomenclature 174 



Observations of pressure comparable 173 



reduced to station elevation 170 



regular barometric 97, 100, 171, 180 



Observed reading defined 174 



Packing barometers 109, 145 



Pens for barograph cleaned 159 



Plane of reference to be adopted 164 



Pressure, actual, defined 174 



of one atmosphere 4 



reduced — 174 



station 174 



tables of, corresponding to change in elevation of 100 feet 198 



Private barometers, comparison of 194 



Pumping of barometers 89a 



Purity of mercury, how indicated 139 



tested 137 



Reading of vernier 12, 13, 14, 15 



Readings of barometer corrected 17 



Recording barometers or barographs 17I 



Reduction to sea level defined 174 



temperature and moisture terms lOd 



.Reduction for elevation defined 174 



Removal correction 174, 182 



to barometer, provisional 1°^ 



variable I82a 



