166 Scientific Intelligence. ‘ 
refractor seems to be better adapted to the color of a Lyre than 
to that of 61? Cygni, and this may be a reason why the probable 
error is Jarger for the latter determination. 
There are no stars which have been so frequently and withal so 
carefully investigated for parallax as Ve 1? Cygni. It 
may be interesting to place alongside of Professor Hall’s elabo- 
rate determinations other published values of the parallaxes of 
the same stars. 
a Lyrze. “ 61? Cygni. “ 
F. Struve OGL thee cee 0°55 
GASB, Potere ois oie: es Wine) Cie db 0°8 j 
© AP Pétera oes es aa) ile 8 0 Se ee 0-348 ; 
Johnson 0-14 OG, Av Pe Potters 22: os. = <p e510 BAF 
O. Struve R1iGs1t ACW Poters. oe cles 0°360 
O. Struve Beer ree 0°384 , 
Maln S154: COnnnOn os ee 0°397 
Briinnow PITT Wolddtedk oo ee 0°523 
Briinnow OR ye ee ee ere 0-509 
Hall 07155 ES ae ae CREE Oe Dae MEINE 0°564 
Hall Ree te 04783 
The excellence of the observations, the character of the instru- 
ment, and the carefulness and skill of the reductions, seem to 
justify our having unusual confidence in Professor Hall’s work 
and result 
as well as the hyperbola. 
e question whether observations ever require us to accept 
the hyperbola as an actual form of orbit for any comet is of 
special interest. Professor W. Beebe undertook a full discussion 
of all the observations of this comet, to determine whether they 
would give the same result as the six used by Encke, whether the 
perturbations by the planets would modify the results, 8” 
whether any effect, and if so what effect, would be caused by 
