498 Trans. Acad. Sci. of St. Louis. 
quently as possible by removing the transit instrument to its 
usual place in the transit room and observing for time. The 
results of observations for 47 of the sidereal clock for the 
period July 14 to August 1 follow. 
AT AND RaTES OF FAUTH SIDEREAL CLOCK. 
Date Siderea Dail Hourly Temp. Fahr. 
1891. Time. FAT Rate. Rate. in Clk, Case. 
July 14 17h. 55m. + 58.58 
ames © aie SG 8 0 — 7 05 —4s .03 —0s,168 69°.5 
—10 .87 —4 .16 —0 .178 70 .5 
vate 17 - 30 Clock stopped/and pend. bob|turned down 3/divs. 
+ 1s.0 
WS Sth ts 26 ont 8 —l1s .09 —0s.045 73 2 
e 8h-| 90. BS ey ay a | —0 .051 69 .4 
“ 99 42 <0 01S snk 08 —0 .043 70.7 
Se) Aias OH Oe cae im BS *,47 ane 9 —0 .050 72 2 
The Observations were made on six nights in July, 1891. 
The new diagonal eye-piece of the transit instrument had not 
yet been purchased and the old one, power 40 diameters, had to 
be used. The verticality of the threads of the reticule was 
adjusted with great care but all observations of transits were 
made near the horizontal thread. Thestars were observed on 
the chronograph and over all five threads of the reticule. 
The instrument was accurately adjusted in the prime vertical 
by means of B. J. stars, which transit the prime vertical at a 
low altitude, and in no case has the correction to the latitude 
for error of the azimuth been appreciable. The inclination 
of tae axis of the instrument was measured seven or eight 
times each night with the new striding level. The value of 
One division of this level was accurately determined in June, 
1891, by myself at the Washburn Observatory, Madison, 
Wisconsin. The adopted result of this determination is — 
1 Div. = 1.784 + 0”.015. 
The results of the level observations for each night were 
plotted in a curve and the inclination of the axis at the time 
of each observed transit was read off the curve. Careful tests 
