(17) 
Observer. a nm Observer. | at n 
Aitken 7.805) 5 |Hussey 7".594) 4 
Bigourdan 7 .507/ 5 [Newcomb 1.747 4 
Burnham 7 .404) 10 [Peirce 7 .576| 4 
Denér 7 .417| 5 [Pritchett (C.W.)|7 .668) 5 
Frisby 7 .776) 4 [Stone 7 423) 5 
Hall 7 .533| 18 [Struve 7 .812) 14 
Holden 7.911! 7 fWilson 7 314) 4 
Hough 7 .358| 8 [Young 1.579 7 
From all the measurements of the above observers I find in the 
mean 7594 for the semi-major axis. The complete system of elements 
by the side of which I introduce for the sake of comparison thie 
one found by Prof. Auwers in 1892, runs as follows: 
System II, 
ZWIERS 
f i 1894. 0900 
m— Sb 
a 
—7°37069 
48.8421 year 
0.5875 
46 EI 
44 30.2 (1900.0) 
212 64 
7594 
System V*, 
AUWERS 
1893. 615 
— 702877 
4G.399 year 
0.6292 
37 30.7 1) (1850.0) 
219 56.5 
7"568 
I have also investigated for systematic deviations the distances 
found in the various years. To each observer of the above table the 
weight 1 was given (with the exception of the 6 measurements, men- 
tionned above), the remaining ones were given the weight 3, evident 
failures being excluded. After the periastron-passage the observations 
of Ser and Boornroyp were omitted. As appears from the table 
1) Reduction to 1990.0 + 16'.9. 
Proceedings Royal Acad. Amsterdam. Vol. IL. 
