PAPER BY PROF. HELMHOL7 



Both these values arf- positive w ■ . bot), 



-here the nd prevails. 



The equation Ae] can also be written 



- --■=': ■"-:■- — ~ ]■ 



la order this may be positive - _ a- 



equality must be s tis led 



-.^ .- 

 or. 



1 



Ordinarily this will be the cac n general 6 ses s unlta- 



neously with p and from a detinue value at the pok 

 the equator. Similarly il so - nd from zero at 



pole to attheequa: r,s that so ine: - - from zero at the 



pole to a dennite 1 s :he equator. We a refbre d - 



ignate this s • :he uv : - - : a only occur under 



special conditions withiu hniit 



Iu the normal ease as we progress »thes 1. the wanner 



3 on the side of the great that is to s . on the side towards 



the equator, and equally on the sule of the _ er r if we p: 9 6S 

 toward the 1 stial t is 1 say,/ and r icereas >rd the 



- ..e side of the boundar - this surface si - aod 



that the tangent of its aieridian section intersects tin s - ere 

 between the pole and the poiut of the hor ingimmed be- 



neath it. Near the equator, where the pole rises the 



horizon, this _ - an inclination to the boundary snrfaof sneh that it 

 makes a very small acute ang :h the horizou. 



In accordance with this, equal - snsl r those cir- 



cnmstances 3— isneg g thebonnd rysurft - f. 



Therefore the r inclination of the bounding sir is in an 



-ending direct ml a p : sitnated beneath the « st 



It on the other hand exceptional lot ss exist 



- ■:■: g»< 



dr 



then in sneh cases rding to equal Bl be I sil : that 



is to say. the boundary line will ascend to higher levels s 

 a the earth's ..\ - 



Since moreover equal ^ 3 isweprooi athedi 



tion of a line drawn re the pole, the warmer air must li g er. tin 



