W. A. Rogers on Variability of Personal Equation. 307 
aor arising from the variability of personal equation, 2 de- 
termining the value of this function by means of artificial stars, 
the observations for this purpose being nearly coincident with 
those of longitude. 
= the Basics of actual stars were made with the equato- 
tial, four, of four wires, constituting a complete set. Thus : 
R observed the first four wires. 
Ty “ last “cc “ec 
R “ec “ “ce “ cc 
A ce “cc first ce cc 
Reducing each observation us the interval from each wire to 
the mean of the wires, and t king the arithmetical mean of 
the Febnilts, the relative oblesceant was found free from the error . 
wire intervals, 
R.—T. from the equatorial. R.—T. from artificial stars. . 
May 31 =—"08°* "hi 
June 2 11 079 
4 15 087 
9 “16 103 
15 “09 071 
17 06 110 
y » 22 16 ‘085 
. — -_ 880 pees fare! _ 1,000 sat isl 
==—’116*. ==— 093° 
I do not asst: assert that this ee will exist in 
every case, becaus 
_ (a): The relat "inight have been different had the observa- 
8 been made with the transit instrumen 
(6.) The same pamease might not exist with other observers. 
most peice las of “the claire! equation. 
