vi CONTENTS. 
PAGE 
Description of the Tables of the Observations— 
Description of the Tables containing the Daily Observations of the Magnetometers, Xvii 
Description of the Tables containing the Daily Meteorological Observations, ... XVill 
GENERAL REsuLtTs OF THE MAGNETICAL OBSERVATIONS— 
Magnetic Declination— 
Corrections applied to the Mean of the Observed Readings, in order to obtain 
the Meansof: the Day, 4.,..puswisves seme sess hee eeen aeiae Cele eee eee Xxi 
Monthly and Yearly Means of Declination, from 1847 to 1855, .................. XXli 
Secular Chane, .o...cess0 Dnnnoniene waese sence ciameebehic aye east ene ee meee eee XXxli 
Comparison of Observed with Calculated Yearly Means of Declination, ......... xxii 
Avimual Variation for the Different Hours, ..2...24:..0s2c. ssa oseasee ee eee eee XXIV 
List of the Years made use of in obtaining the Annual Variation, ............... XXiv 
Annual Range for. the different. Hours, 1.1000. <<aeccuseeraveseneve dndedduplyaticeentnn all XXV 
Horizontal Component of Magnetic Force— 
Corrections applied to the Mean of the Observed Readings, in order to obtain the 
Mieani ‘of the Daye iia. cucaitenos tGecbyecee chan Sead one ter meet eee eee XXVi 
Monthly Means of Horizontal Force in Scale Readings, from 1847 to 1855, ... Xxvl 
Apparent Secular Increase in parts of Force, 60.0. eausmt~sseoucnedeacasae ens XXVil 
Annual Variation for the Different Hours in parts of Force,..............0...-+000- XXViil 
List of the Years made use of in obtaining the Annual Variation, ............... XXVill 
Annual Range for the Different Hours,..................4+ bee ae eeeeor NeSRERR hein XxVill 
Maenetica Opservations 1847 to 1855— 
Daily Observations of Mapmetometers, ac. 0st.0 < sqcine oem i sleleinider vie = sa etaliamaniaelsleaiels rae oiet 1 
METEOROLOGICAL OBsERVATIONS 1847 To 1855— 
Daily Meteorological Observations, . ...........sc0ssensereislsadiblenicleds. duldsbeukdiswantianas 49 

HRERAT A. 
In the column ‘ Bifilar corrected” for December 11th, 1848, 11 a.m., instead of 56:10 read 561:0, 
In the same column for December Ist, 1848, 11 4.m., instead of 56°85 read 568°5. 

