73 
the pair must have been very close in 1897 (Bryant: “round”, 
Lewis: “possibly elongated”), that there are tolerably concordant 
measures by Bryant and ArrkeN about 1903, and that the pair is 
single again in 1904 (Hussey) and 1906 (Arrken). Because of their 
large discordances the measures between 1893 and 1914 have been 
omitted in the computation of the orbital elements, though it will 
be of interest to see how they are represented. 
The observed distances, plotted against the time, show symmetry 
about the epoch 19048. Therefore | assumed as a first approximation, 
that the major axis and the line of nodes are coincident, so that 
we have: 7'—1904:8. and w= 180°. Provisional values for the 
other elements were derived graphically, the period by measuring 
the areas of two sectors. These values are: 
P 280: years-e 0:83 a 0"89.2. +476 2, 10707. 
They give already small residuals for the reliable measures, but 
a marked systematic deviation of the angles between 1866 and 1893 
shows, that the assumption w — 180° is erroneous. Normal places for 
the epochs 1830, ’40, ’50, ’60, ’70, °77, ’84, ’90, 1915 and 1921 
are derived from interpolation-curves of angles and distances, and 
a solution by the method of least squares, using Comsrock’s formulas 
(The Orbit of © 2026, Astr. Journ. Vol. XXXI N°. 725) and giving 
half weight to the distances, gives the elements: 
T 1901-73 
P 295°6 years 
e 0:823 
a 093 
A) 169°2 
i + 82°04 
Q) 110°6 
angles increasing. 
The measures of the next decade will give a better definition of 
the present half of the orbit, and consequently a closer approxi- 
mation of the elements. 
The hypothetical parallax, aP~*s, is 0"021. If we adopt the mean 
value for the sum of the masses, given by AITKEN in The Binary 
Stars, 1°76 ©, the parallax will be 0’018 and the mean distance 
52 astronomical units. The maximum difference in radial velocity 
is then 17 km. per second. The spectrum is /’8 according to the 
Draper Catalogue, and the photographic magnitude of each component 
is 8:5. The pair should have been observed with a large spectros- 
cope in the neighbourhood of periastron. The absolute magnitude 
of each component is 8:5 + 5 log 0:018 = + 0-1, in good agreement 
with the value to be expected from the spectral-type. 
