Numerus constans nutationis. 



177 



Simili modo accipimus: 



pro 1900 



a'-a=(l+i){ -15"832lSin Q — [6"8683Sin«Sin Q +9"224-0GosaGos Q]tgb 

 -f- 0,l903Sin2Q + [0,0822Sin aSin2 Çl +0,0895Gos aGos2 Q ]ig ô 

 — 0,1872Sin2C — [0,0812SinaSin2C+0.0885GosaGos2C]^g^ 

 +0 , 0621 Sin ( C —T) ^ 0,0270 Sin « Sin ( C —F') tg ô 

 4-0,000154Gos2a^g5^Sin2Q — 0,000160Sin2«f^5*Gos2Q j 



-f(l-2,162i+3,1620 { — l''l64-2tSin20— [0"5052SinaSin2O 



-f0"5506GosaGos2O] 

 + 04170Sin(O— r) + 0,0507Sin«Sin(O— r)%<5 

 — 0,0 1 9 5 Sin ( O +r) — [0,008 5 Sin a Sin ( Q +r) 



+ 0,0092GosaGos(O-|-r)]fg^ I ; 



a'-3=(l+i) j — 6"8683GosaSinQ-l-9"224-0SinaGosQ 

 4- 0,0822 Gos a Sin 2 Q — 0,0895 Sin a Gos 2 Q 



— 0,0812Gos«Sin2C4-0,0885SinaGos2C 

 4- 0,0270 Gos a Sin (C — F) 



— 0,000077Sin2ai^5Sin2Q —[0,000023 



-f 0,000080 Gos 2 a] ^g- 5 Gos 2 Q j 

 4-(4-2,162i+3,162^) j — 0"5052Gos«Sin2O + 0''5506SinaGos2O 



+ 0,0507Gos«Sin(O-r) 



— 0,0085 GosaSin(O-}-r)-l-0,0092SinaGos(O+r)j . 



Jam comparemus cum nostris formulas a cl. Besselio {Schum. Astr. 

 Nachr. JW 83) pro 1800 evolutas, in quibus nutatio — 9''6't80 supposita 



est, substitutione valoris izz. — ita mutatas, ut nutationi 9"22305 



9 64S0 



respondeant. Sic prodeunt nutationes ad mentera Besselii sequentes: 



