Airy 
Phil TrcuisMDC GCIPL Plate XXIV. 
Curves representing the Diurnal PegixaPPes of Magnelxsm inferred/ -from ike Galvouvic Currents registered./ at' the Royal 
Observatory, Greemvieh-. The or Proxies are meoLsuu~ed from the Zero found hy interrupting gaivouuc circiui . their wmt 
is 0:0000 1 of Total Hoiizontal Force . The numerals upon the curves oUnote Pours of Greenwich PI earn Solcu J Tune 
W. West vmp 
