CONTENTS. 
PAGE 
InrRODUCTION— 
J POGEGVOs Ea euRepeOos Soe Dou POCSOCE PORTE COLORES ADEE eee Rees cee are watiDee sagen fe vil 
Position and. Description of the Observatory, .c.accaesct- ssmnetiany eles tee deringuedarwed cojwanes vill 
ISUSLENCPMOUSETUACION,” Mt inner enecrns.r See eae. decease i Gee ere Stee seas oteSegnn du aR. vill 
Declinometer— 
Waluesion the Instrumental Constants, ....e.s..1eecu-ore co +-meeg cence seer tne tencersese vill 
Wotes heaarding they Wechmometer,” ccrassces ued atuewener ress acig icceneaeineree Sons 1X 
Bifilar or Horizontal Force Magnetometer— 
Meseriptioutoh ther Instrument 1... 6. cera ace ewe tee snalcnecrenele Recs get ts states x 
Values of the Instrumental Constants, for January 1847,..................00000e eee xi 
Correction owing to the change of plane of the Balance Magnet in January 1848, xl 
Values of the Instrumental Constants, after July 8, 1851, when the Torsion 
Gixcletwmasmnurmed st emren a ce oncent Sonne as cum eees needa ascnstety lace nee xii 
Balance or Vertical Force Magnetometer— 
Weseripitonvob tie pMnSCEMEIeIE, -.i.sk asicctes oats os nares Hage Chae aoe gaa ates Meal ee xli 
Values of the Instrumental Constants for January 1847,..............cceeseeeeee ee xiii 
Values of the Instrumental Constants, after the change of plane, in January 
GAG rede oatac nee tee cneaaie ne’ UNO Nena IS OM eae e akon. ae ee Age oa eisia dle ore xiii 
Note Regarding a supposed change in the Readings after July 1851, ...... diction XV 
Barometer— 
Corrections applied tothe Observations,! 0... .jorcssc-n<thiagensareviccderndoesleoces < XV 
Thermometers— 
Corrections for Newman’s Standard Thermometer, ...............cceccscceeceves nae XVI 
Corrections for the Dry and Wet-Bulb Thermometers, ..................eceeeeeeeees Xv1 
Rain-Guage— 
Description and Position of the Observatory Rain-Gauge,..............cccceeeeeeees Xvi 
Vanes and Anemometer— 
Method of Indicating the Direction of the Wind, ..........cccccceccesscsssccevceees XVil 
Method of Observing the Anemometer, ................ MO 0 oo Ns sik cistg xs aan - Xvii 
State of the Sky— 
Method of Indicating the Amount of Clouds, ......... 2a ABER rene cnc ence Xvi 
Notes Regarding Meteorological Instruments... cc.rcsccacssoecccscsaccccencssetonececrseces xvil 
