Chase.] -j4o [May 2 anl 16, 



/ c. o. »2 + o \ p rpj, e i a ^ er coincidence is within less than one seventieth 



of one per cent. 



The synchronism, between light oscillations from Sjin to Uranus's mean 

 aphelion and planetary revolution at Sun's surface, lends interest to the 

 following approximate ratios of the spheral radii to Uranus's mean 

 radius vector : £ , ( f ; ?, i ; 0, £ ; d\ | ; %, £; [\ $ aphelion r. v.] 



JEthereal Spheres of Rotary Undulation. 



Spheral r. Periph'l v. Yel. of light. 



g (b_ c. o.* %) mean. 657,654,500 660,434,400. 



9 (h c- O; ©) " 659,608,000 " 



(©, #) ■" 663,492,000 



tf(k c.o., &) " 660,348,000 



2/ (9, 20 " 663,492,000 



1 2 (h, 2/) c.o. 661,659,000 " 



Comparison of Harmonic and Actual Spheral Radii. 



Approximate. Actual. 



g f g mean 915.91 X r. 920.91 



J | •' " 824.32 " 824.66 



© i " " 686.93 " 696.11 



tf | " " 2472.95 " 2478.64 



y, i " " 686.93 " 696.64 



] 2 | " aphelion, 1435.50 " 1458.75 



IV. WEATHER STUDY. 



In the "American Weather Notes," which I had the honor of commu- 

 nicating to the Society at its meeting of March 3, 1871, I first called at- 

 tention to the comparative frequency of anti-cyclonic storms, and to some 

 other peculiarities of meteorological phenomena which indicate the impor- 

 tance of regarding Espy's lines of indraught, as well as Redfield's cen- 

 tres of cyclonism, in making weather forecasts. I subsequently showed 

 {ante, xii., 65, 123) that the general atmospheric movement in America 

 is anti-cyclonic, while in western Europe, where I had looked for very 

 marked cyclonism, anti-cyclonic are nearly as frequent as cyclonic cur- 

 rents ; and that two of our principal storm centres are situated near nor- 

 mal intersections of polar and equatorial currents. 



An abstract of my views was subsequently published in the manual of 

 the Signal Service Bureau, and the officers of the Bureau have communi- 

 cated to the public journals some remarkable evidences of anti-cyclonism 

 in storms of great magnitude. It therefore seems desirable to ascertain 

 the extent of this apparent exception to the generally received law of 

 storms, and I have accordingly undertaken some special study of the 

 vi eather maps, in order to ascertain how far my ideas are sustained by two 



* It is well to remember that Saturn's centre of linear oscillation is at the centre of gravity of 

 the planetary system, and its reverse centre is at the octave node of the centre of gravity. 



