68 
Transactions of the Boyal Society of South Africa. 
Borehole No. II. on Jan. 27 at 6.25 p.m. gave llj galls, in 44 sec. 
28 11.55 a.m. „ 45 „ 
3.0 p.m „ 44 „ 
„ 6.55 p.m. 45 ,, 
Borehole No. IV. on Jan. 28 at 9 a.m. gave 11^ galls, in 45 sec. 
10.30 a.m. 
12.40 a.m. 
2.25 p.m. 
3.35 p.m. 
5.5 p.m. 
6.35 p.m. 
44 
44 
44 
45 
45 
45 
Borehole No V. — 
Jan. 27 at 
12 noon gave llj 
galls, in 12 sec. 
= 56*6 galls, per min 
1 p.m. , 
13 „ 
= 52-3 
5 p.m. , 
15 „ 
= 45-3 
28 
8 a.m. ,, 
17 „ 
= 40-0 
9 a.m. , 
16 „ 
= 42-5 
10.30 a.m. 
14 „ 
= 48-6 
12.30 p.m. 
13 „ 
=: 52-3 
2.20 p.m. 
13 „ 
= 52-3 
3.30 p.m. 
14 „ 
= 48-6 
5 p.m. , 
14i „ 
= 46-9 
6 p.m. „ 
15 „ 
= 45-3 
7.45 p.m. ,, 
14 „ 
= 48-6 
29 
9.55 a.m. ,, 
161 „ 
= 41-2 
10.50 a.m. 
15 „ 
= 45-3 
Thus it V70uld appear that No. Y. alone exhibits a notable variation in 
yield. 
It will be observed that on January 28, between 8 a.m. and 8 p.m., the 
yield rises to a maximum in the neighbourhood of 1 p.m. and falls to a 
minimum about 6 p.m. 
This No. V. borehole opened into the bottom of an iron tank about 
2 feet square and 2 feet deep. An exit pipe of 5f -inches internal diameter 
at the side of the tank conducted the water from the small tank A for a 
distance of about 15 feet into a larger and much deeper tank B. (See 
Diagram 2.) The water on emerging from this pipe had a drop of several 
feet through air before reaching the level of the water standing in B. A 
second exit pipe from the bottom of B led the water into a dam about 
100 yards distant. 
It was observed that the level of the water surface in the small tank A 
was always higher than the upper edge of the first exit pipe. This is 
