55 == 
Time of, | | Time of 
Green- | AE | :HÄD | AV Green | dE! HAD 
wich. : wich. 
7h10nl 89| 54A| 91 | 721 8.9 5.1 
el 9.0 52 22 89 5.1 
12 9.0| 54 30 arl bol an 
13 9.1 5.6 80 5.4 | 10.0 
14 9.1 5.6 30 |— 9.3 7.8 | FE 
15 9.0| 5.6 9-0 |=126[ <91 ARB 
16 8.8 54 30 |—16.3| 10.3| 28.9 
17 8D Oele 10 0 211 | 48:90 | 340 
18 8.8 51 30 |—-19.5 | 15.2| 35.1 
19 8.8 5.1 11 0 |=16.3| ‘16:41 GRS 
20 8.8 5.1 8.4 
On the plate the trace of the horizontal vector for Karang 
Sago on May 18*, 1901 and that for the period May 9—17 
(scale 1 mm. — 0.2 7) is inscribed (fig. 1). Fig. 2% gives 
the same for Batavia on the same scale and fig. 2% on a 
scale of 1 mm. —= 1 y. Fig. 3 gives the oscillation of the 
vertical intensity at Batavia on May 18'* and mean oscillation 
for May of the minimum sun-spot year 1887. 
Fincly the mean May-vectordiagram for the period 1883— 
1899 for Batavia has been inserted as figure 4. 
Let us first submit these figures to a closer examination. 
The average curve deseribed by the extremity of the horizontal 
vector at Karang Sago and at Batavia, deduced from the 
period May 9—17, fairly corresponds with that according 
to the May-diagram 1883-1899 but for the fact that at 
Karang Sago the maximum morning-elongation was not reached 
before 5.18 Gr. t. 
The magnetogram for Karang Sago for May 18'* shows 
that this maximum elongation was reached at about 4.0 Gr. t- 
