589 



different laws. The westerly deflections have their chief prevalence 

 from 5 A.M. to 5 P.M., or during the hours of the day, the ratios at all 

 the other hours being below unity. The easterly deflections, on the 

 other hand, prevail chiefly during the hours of the night, the ratios 

 being for the most part below unity at the hours when the westerly 

 are above unity, and, conversely, above when the westerly are below. 

 The easterly have one decided maximum at 11 P.M., towards which 

 they steadily and continuously progress from 5 P.M., and from which 

 they as steadily, and continuously, recede until 5 A.M. the following 

 morning. The westerly appear in both records to have a double 

 maximum, one about 6 or 7 A.M., the other about 2 or 3 P.M. 



TABLE showing the aggregate Values of the larger Disturbances of 

 the Declination at the different hours of solar time in 1858, 1859, 

 1860 and 1861, derived from the Kew Photographic Records; 

 with the Ratios of Disturbance at the several hours to the mean 

 hourlv value taken as the Unit. 



