— 219 — 
Total Eclipse of the Sun of August 18, 1868. 
Jourse of central line: Cochin-China, North-Borneo, North- 
Celebes. Minimum distance from Batavia + 12°. Maximum 
phase at Batavia + 0" 15" p. Available are eye-readings of 
Declination at Batavia. !) 
Hourly values of D at Batavia give much indication as to 
the course of the variation in D, because this element. is 
commonly very quiet in these regions except on days of 
greater disturbance. Besides, the year 1868 was magnetically 
quiet. 
Below are given the hourly deviations from the daily mean 
for the eclipse-day and of the average hourly values for the 
month (Easterly deviation is.reckoned everywhere positive, 
westerly negative). 
How. WS" A. Mut eter. E 
6^ a 1.'8 1.'0 1"p —1.'8 —0.'8 
7 1.9 R5 2 —0. 7 0. 1 
8 0. 4 0. 6 3 0.3 0:4 
9 — 1.1 —0.9 4 152 Ka 
10 —1.8 —1.7 5 Li 0.7 
11 —2.1 -—1.9 . 6 0. 4 0.3 
Noon —9.5  —1L4 
In the plate I have plotted both curves, not by joining the 
points representing the hourly values by straight lines, but 
by drawing the most probable curve through them; this 
iving a nearer approximation to the true curve than a 
broken line. 
Looking at the curve of August 18' the most striking 
feature is the deviation from the normal at noon. 
Til 11ba the two curves are closely parallel, but afterwards 
) Observations made at the magnetical and meteorological observatory at 
Batavia, Vol. I. : 
