15 
Observations of « Cygni. 
For this star the mean zenith distance Jan. 1, 1819, has been sup- 
posed = 8°.4.4/ 55”,60—e. 
The four resulting equations that have been deduced from 228 
observations are 
1. 228¢4 54,802—34,64p—22,22:+83,00=0 
2. 54,80e+91,49640+26,9658p—15,48342+3,0558=0 
3. -34,64e+26,96582+92,0096p—34,20842—37,2714=0 
4. =22,2%—15,48347—34,2084p + 98,13382—42,1174=0 — 
Whence 
z= +0",5572 
p= +0,5003 
z= +0,0624 
e= —0,2487 
Here also the value of z comes out considerably exact. 
The three equations for obtaining probably more exact values 
of p, 2 and e, are 
1]. 228¢ + 54,801—34,64p+72,94—0 
2. 54,80e + 91,49642 + 26,9658p—4,9208=0 
3. -34,64e + 26,9658 + 92,0096p—53,6798—0 
Therefore 
x= +07’,0802 or const. aberr. 20”,35 
p= +0,4584 or 2p =0",92 
e= —0,2696 or mean N. P. D. Jan. 1, 1819=45¢ 21’ 49”,37 
The value of the semi-parallax is probably exact to 3, of a second. 
