542 



importance. At present over twenty wells have been put 

 down within the area, and water is pumped to Ooldea at the 

 rate of 10,000 gallons a day. It is legitimate to assume that 

 the vegetation within the Soak basin has suffered somewhat 

 from human interference, and it may suffer still more if 

 pumping permanently lowers the water level. Mr. Brown, 

 referring to his visit about 1887, speaks of ''clumps of bull- 

 rushes'' growing here and there. None are there now, while- 

 of the plants collected by us only Adriana tomentosa — locally 

 called "water-bush" — seems definitely indicative of consider- 

 able edaphic water. Within half a mile of the Soak, in a 

 north-easterly direction, lies a salt lake or clayjpan, smaller 

 in area than the Soak itself. This was dry at the time of 

 our ^^sit, but the friable soil overlying the clay bed was 

 impregnated with crystals of soluble salts, including gypsum,, 

 that caused a white efflorescence at the margins. 



Climate. 



Climatological data for Ooldea were not kept before 

 December, 1916, because, until the construction of the East- 

 West Railway, there was no settlement at the place. From 

 that date rainfall records have been kept, the temperatures 

 have been recorded less regularly. The actual figures cover 

 too short a period to allow of generalization on them 'alone, 

 but, taken in conjunction with what is known of other places 

 similarly situated, they are useful. 



The following table gives tlie rainfall in inches from 

 January, 1917, to October, 1922 : 



1917. 1918. 1919. 1920. 1921. 1922. 



Januarv ... 2-50 O'OO 0-70 0-00 0-03 0-00 



Februarv ... 1*15 0*00 l-m 0-00 2-83 0-5^ 



March ' ... 1*18 I'OO 0-00 0-06 0-28 0-71 



April ... 1*24 0-60 2-11 1-00 0-01 1-27 



Mav ... 0-51 0-63 0-06 1-39 2-13 0-2.> 



June ... 1*49 1-06 0-2o 0-45 0-91 0-74 



July ... 1-48 0-16 0-16 0-68 0-15 0-25. 



August ... 0*22 1-19 0-57 (V69 0-15 0-0C> 



September ... 0*76 0*29 0*08 2-32 0-03 0-00 



Octolw ... 1-69 0-72 0-54 0-64 0-36 0-1-^ 



November ... 1*16 1-31 0-20 0-49 0-93 — 



Decemljer ... 0-73 0-39 0-33 042 0-^5 — 



Total for Year 14-11 7*35 6-63 8-16 8-16 *3-96 



A\'ot Days ... 65 30 27 47 43 *2T 



*Totals for 1922 on figuivs for 10 months only. 



