Investigations Beg ar ding Brack'' (Alkali) in Cape Colony Soils. 135 
These results are favourable towards the suitability of the soil for 
irrigation, but, at the same time, had opportunity offered, it would have 
been desirable to extend the investigation to 3 or 4 feet lower down, for 
reasons already detailed, in the manner illustrated above. 
Division of Colesberg. 
Six soils from the farm Oorlogspoort, in the Colesberg Division, were 
also examined with a view to ascertaining the proportions of soluble salts 
present. These were found to range between "038 and "090 per cent., and 
to average '058 per cent. Such amounts are not sufficient to be harmful 
to plant life, even if the salts consisted* entirely of sodium carbonate or 
"black alkali," the most injurious form in which alkaline salts are found 
in the soil. 
Division of Beitstown. 
One of the first investigations into the possible alkalinity of lands pro- 
posed to be irrigated was carried out in connection with the farm Houw 
Water, in the Division of Britstown. Five sets of samples were taken in 
almost a straight line, nearly a mile and a half from end to end, from the 
lands intended to be irrigated, below the site of the proposed dam. In 
each case samples were taken in the manner already described to a depth 
of 6 feet. The physical nature of the soil may be gathered from the 
following table : — 
HOUW WATER (BRITSTOWN DIVISION) SOILS. 
Surface. 
A. 
B. 
C. 
D. 
E. 
1st foot 
2nd foot 
3rd foot 
4th foot 
5th foot 
6th foot 
Fine loose loam 
Stiff compact clay 
)> 
)i 
Very loose loam 
Fine loose loam 
Stiff hard clay 
»> 
Very loose loam 
Loose loam 
55 
Stiff hard clay 
55 
55 
55 
Loose loam 
5 5 
Rather stiffer loam 
55 
Stiff hard clay 
Loose loam 
Loose loam 
55 
55 
Rather stiffer loam 
Looser loam 
Moist loose loam 
The approximate distances apart of the points whence these samples 
were taken were as follows : — 
Between A and B 430 yards 
„ B „ C 250 „ 
C „ D 850 
„ D „ E 900 „ 
Time and circumstances did not permit of any thorough investigations 
into the depth of the water table below the surface, but as the average 
annual rainfall is very low — only about 5 inches — and as E was the only 
one of the five probings which showed a suspicion of moisture within 
