and these enabled me to correctly delineate the curve, 

 instead of showing only the maxima and minima of the 

 spots, and connecting these points by straight lines as is 

 sometimes done. On a first inspection, I must confess that 

 T thought some coincidences could be traced in the com- 

 bination of lis. 1 curves in their relation to the Lake George 

 curve; but when carefully studied I soon realised that so 

 far as the moon's curve is concerned, there can be no real 

 agreement between a curve resulting from a periodicity of 

 18*6 years as the moon's curve is and one based on the 

 assumption of nineteen years' periodicity, for the reason 

 that in course of time one would be seen to be slowly creep- 

 ing over the other. The sun spot curve is so very irregular 

 within the limits of the diagram that nothing tangible 

 results from a comparison with the Lake George curve as 

 extended back into the past. It is possible, of course, on 

 the assumption of 114 years' periodicity, which the Nile 

 curve would appear to indicate (Plate 2, fig. 1), or of even the 

 longer period of 171 years which can be traced in that curve» 

 and also in the British rainfall curve {Plate 1), that the 

 peculiar curve of sun spot frequency may be found to be 

 repeated ; but unfortunately we have no reliable data so 

 far back as to afford a comparison, and must perforce 

 wait for future developments. 



The Nile River Floods.— I had long wished for some 

 definite information concerning the heights of the Nile 

 River floods, in order to ascertain whether there were any 

 indications of periodicity in the rainfall over its catchment 

 area in the Abyssinian table land, and I was much pleased 

 to find in Colonel H. E. Rawson's paper on "The Anti. 

 cyclonic Belt of the Southern Hemisphere," previously 

 referred to, a table giving the ratios of annual Nile floods 

 to the mean flood from 1869 to 1905, taken from the Report 

 of the Director of the Egyptian Survey Department. 1 



