ChxxmJbizrs. 
Phil. Trams. 1887. A .Plat# 3. 
Gobocbcu Obse/rvcutory f Borrubcuy. 
Carves representing , for cu full/ lunation, and, for the; qvuarter November to January, that/ part/ 
of the/ solar diurnal, variation/ of derlination, which; runs through/ a, cycle, of change/ uv a/ lunatcon. 
Dotted; curves _ _____ calculated; by the/ formula; 
f c (h) cos -^JF ~b h fjh/) sin, t-t f c (K) cos 2 t + sin, 2 ~y~t/ 
h, being the, solar hour, t the, cuge of the, mocm, and, P the, mean period/ of a/ hmxxUon/; and; 
ffh), j^(K), foe each being a/ constant; solar duurnal, variation,. 
thudr line, curves _ calculated, by the, last, two terms only- of the, same, formula;. 
Thin Une curves. _ vaj- lclLlo rce givens by observations. 
An, irudrecLse (izpwaa~cb rrurverncritt J of One mAh/ mu the/ orcLmuoute^ indfc/xteG emu rnwrecte of the/ 
eoueterby nruougnekic force/ of ■ 000048 C- G S units. 
The/ members withe which the/ curves arc rnourkeds represents the/ days before ( J or after (^~) A ew Moons. 
"West, Nevrmnn &. Co hth 
