Page:Proceedings of the Royal Society of London Vol 60.djvu/111

96

§§ pa g e 1 Historical and descriptive............................................................................... 96 12— 3 Interpretation or electrograph records .............................................. .. . 98 4 Selection of stations ........................ . ................................................ * ........... 99 5—6 Comparison of results at the different sta tio n s.......................................... 100 7—9 Eatio of readings at different stations, at different times, and under different meteorological conditions........................................................... 102 10 Comparison cf water-dropper and portable electrometer .................... 106 XI Defects in instrum ents....................................................... 108 12 Checks recommended ...................................................................... 109

13—15 Theories of Exner and of Elster and Greitel.............................................. 110 16 Method of treating Kew observations ...................................................... 112 17—19 Anticipation of some objections : want of uniformity in conditions as to wind, and cloudiness; proximity to London....................................... 112 20 Tables of results, including particulars as to potential, vapour density, velocity........................................................................................ 114 21 Analysis of preceding tables according to voltages at base station. . . . 123 22 Further tables, each containing analysis according to magnitude of some one meteorological element.. . . ......................................................... 125 23 Discussion of possible influence of vapour density ................................ 128 24 „ „ relative humidity .............................. 128 25 ,, „ sunshine..................................... .. 128 26 „ „ ', tem perature................. 129 27 „ „ barometric pressure............................ 129 28 „ „ wind v e lo c ity .......... .......................... 129 29—30 General summary of bearing of results on theory .............................. 130 96 Dr. C. Chree. Observations on Atmospheric
 * humidity, sunshine, temperature, barometric pressure, and wind

§ 1. An electrograpli belonging to the Meteorological Office has been in operation at Kew Observatory, with interruptions, since 1861. The results obtained in the early years of its existence were dis­