Oflioo of the Chief Signal Offieer, 



lyjTED STA TES A UM 1'. .si 



n.artc<l from Aoliu.l observations lake. Sliflflllai.c.MisIy. Scries o...nmencl..s: N 1^^^,.. ,„,. 



>'o. V. 



/ 



PREVAILINO WINDS. 

 Arrows show the direction of, and fly with, the wind 

 Force is shown as follows : 



PUBUBUED BY ORDER OF THE SECRETARY OF WAR 



pYllBOLS. 





Force, 



5^ 



1, 2 

 3, i 

 5, « 

 7, 8 

 9,10 



Telouity. 



Miles per 

 hour. 



to 

 9.1 to 22.0 

 22.6 to 40.9 

 40.6 to 67.5 

 e7.« uy.. 



OKUKK Kfe ina ob«.«.»." 



BRIO. GEN. (BVT A88CD) CHIEF SIORAL OFFICER. U. 



Metres per 

 second. 



to 4.0 

 4.1 to 10.1 

 10.1 to IS.l 



18.1 to 30.2 



30.2 & over. 



/..^-' 



INTEKNATIONAL MONTHLY CHART. , 



ShowlDK mean pressure, mean temperature, meau force .nd prevailing d|4f f " °^'""''' "' 

 7:30 AM., Washington mean time, for the month •> December. 1(;S, ba*«l 

 on the daily charts of the InteruaUonal BaUetm. 



ISOBARS AND ISOTHERMS. 

 Isobars in blue; detached barometer means 



ineans in degrees Fahrenheit. 

 Broken lines, are doubtful. 



